Mgb overdrive solenoid test. ) fiber washers from under the switch and re-install.

Mgb overdrive solenoid test Wasn't sure what to do, so I ignored and kept checking. On road was dropping in and out. Checked the switches. Sometimes cleaning On my 1979 mgb the overdrive is not working. Ordered parts inc filters/o rings and set about replacing. PS With the cover removed, mass connection is gone and the feed loop on the solenoid broken, so the test mentioned in your post does not tell you anything 1980 MG MGB "Red On Red On Red" Jul 17, 2018 12:44 PM. When I moved the gear lever from the 1-2 plane to the 3-4 plane I expected to hear the solenoid click, but it MGB GT or Roadster Overdrive Filter. 9 Conversion, 1977 Triumph Dolomite 1850HL, 1971 MGB roadster now sold. I recently tested the overdrive transmission that I bought from a forum member a year ago. I also got an engine with 50,000 original miles on it. Using the typical manuals and John Twist videos on the subject, I started by removing First, check the oil level in the gearbox. It has two coils wound internally. Drained gearbox stripped out and cleaned NR valve. There is a switch for the reversing lights and a switch for the overdrive both fed by an aging wiring loom. You will not hear a second click because it takes hydraulic pressure within the overdrive unit to push the solenoid plunger back down to where it could click Check the MGB wiring diagrams for the appropriate model. I did this so far 1) installed a new swiths on the gearleaver. It is obviously malfunctioning. When I connect the spare to a 12v battery it does engage, but the piston t A delayed engagement of the overdrive on an MGB can be attributed to a failed solenoid. You can't really hear the solenoid action on the LH Overdrive with it installed as it is inside the casing. Then test the electrics, in and out by itself: This situation is caused by the failure of the tiny O-ring at the top of the solenoid piston. New gearstick switch. Dear Guy's, I'm having trouble with my MGB 1980 overdrive. In overdrive-overdrive does not work: Test for an electrical problem by piercing the solenoid wire with your test light with the ignition on, the overdrive switch on, and the gear lever should be hot. On my previous MGB GT which had a vacuum switch the overdrive wouldn't disengage on full throttle even though I had switched it off with the dashboard switch until I lifted off the throttle. Overdrive solenoid confirmation question #1. But NO HyD pressure registering on the dedicated gauge I purchased when screwed into the plunger port So to refresh I have recently acquired a '73 MGB. 5 MGB-GT I received my overdrive o ring kit and I'm about to start the service work on the overdrive. 6. I could get My overdrive is up and functioning again. Overdrive Solenoid. Side fill plug (NO dipstick) 5. They show the 3 main elements of the overdrive that can be serviced with the gearbox in the car. You will not hear a second click because it takes hydraulic pressure within the overdrive unit to push the solenoid plunger back down to where it could click This afternoon I thought I would check the overdrive (LH type) and applied 12v to the yellow/red wire with the negative from the battery connected to the gearbox case. If it still has power and no click, pull the solenoid (small square cover) and see if the wire is shorted against the case going into the solenoid. What can I do Whether there is constant voltage on the solenoid or not of itself means nothing because as Gerald says it also takes 15-18mph of speed for the OD to develop the pressure it needs to actually engage so if it's stuck Fill to correct level ,test electric circuits,and go This afternoon I thought I would check the overdrive (LH type) and applied 12v to the yellow/red wire with the negative from the battery connected to the gearbox case. As far as a thicker gasket goes, the standard gasket has a large hole which allows the base of the solenoid to sit against the cover. Fitment . Time and time again your postings have been very helpful and I appreciate your input and assistance. Started by Mag9; Feb 9, 2023; Replies: 2; Austin Healey. Initially, it seemed that when I was decelerating around 60 mph the car would quickly drop in and out of overdrive. Square clutch fork boot 4. 1962-1967 MGBs with a 3 main synchro gearbox used a “D-Type” Laycock overdrive My point was that the solenoid in the video must be from a D type OD. So all that's needed is power to one terminal of the new switch, and then one wire from the new switch down to the overdrive lockout switch on the shift tower, and then a short wire from the lockout switch to the overdrive solenoid. A mate of mine says its the solenoid. I’m a helicopter pilot and I thought that was a reasonably stressful occupation until I had an MG!! I had some questions about the described cause and cure, subsequently found Paul Walbran's web page (scroll down to Overdrive "Pumping") that at the time described the same problem and solution, and left me with the same questions. pdf A good article from the MGOC website explaining checks to do if you have problems with the overdrive unit. It runs great, shifts smoothly, but the OD doesn't work. The overdrive is activated by the flick of a switch on top of the gearshift. We did connect a test pressure gauge to the test port on the OD and pressure changed in line with specification each time the switch was operated - this was done on a hoist with the rear wheels turning (rebuilder I am doing a bench test of my new to me overdrive transmission before I install it into my car. I have replaced the I just converted my '73 B GT to overdrive by picking up a used tranny that was equipped with one. Note that the plunger will not operate with the test bulb in series, this is just an electrical continuity test, not a functional test of the overdrive unit as a whole. I Am I correct in thinking that the solenoid should click audibly? Will I have to remove the solenoid and clean it? Overdrive is a mystery to me but that was probably 5 years ago. Posted by nrw34260 . When changing your gearbox oil drain the overdrive unit and clean the magnetic filter element under the rectangular sump cover. Part number 37H1942. ODSpares How does one know if a component is bad, such as the solenoid switch? Also looking for a diagram to know how it is wired. Overdrive Solenoid oil leak. Also to make sure I have everything I need for it. Barrie Jones says “the initial current is about 16 amps but once latched, the holding current is only 3 amps. I recently got a 1980 MGB roadster and the overdrive does not engage. This could be caused by a number of things: The best way to proceed is to break the circuit into sections and test for power. I have watched the John Twist videos as well. 25 kg: Reviews There are no reviews yet. Next we drained all of the oil in the gearbox and overdrive unit. Hi guys - I'm still having issues with my J-type OD. All was well until I dropped Are the wires going to the unit in the case for a solenoid? This all appears to be after the main gearbox case. Since it's a lockout it serves as a backup to ensure the OD is only engaged in 4th (and maybe 3rd). 1969 MG MGB MkII. What is the best way to test it to see whether it is working properly? Check the MGB wiring diagrams for the appropriate model. 1970 MGB Roadster 1970 MGB Roadster. You may or may not have such a I've been doing the long, tedious work of refurbishing an OD unit (later LH style) to be put in my B. I just converted my '73 B GT to overdrive by picking up a used tranny that was equipped with one. 1968-80: 1: MGB: Gearbox & Driveshaft, Relays, Switches & Miscellaneous: Overdrive Electrical Components : 46: VALVE ASS'Y. For Sale MGB Black Label Overdrive For Sale Or Trade For New RB Parts. Later blue label units allowed overdrive only in fourth gear. During one of The rubber bumper cars are fitted with a Laycock overdrive situated at the rear of the gearbox. All the parts inside the overdrive are accessed from the front (gearbox face) of the overdrive unit, so the overdrive has to be separated from the gearbox. The gearbox is in the car. We tried to give it direct power, bypassing the wiper switch, but still no sound from th With any MGB or a derivative fitted with a Laycock D or LH overdrive, there is a surge current when the overdrive solenoid is switched on. Overdrive Solenoid - How to test. Overdrive Pressure Test. When I moved the gear lever from the 1-2 plane to the 3-4 plane I expected to hear the solenoid click, but it I put an LF (Black Label) Overdrive transmission in my 1977 MGB. We first had to install a known good solenoid to replace one that did not work. The only test you can do easily is the solenoid. But as the seat of the valve is part of the solenoid assembly, that will move out as well, so the plunger and the valve seat will have the same relationship and travel as before. Removed the solenoid checked the resistance 15 Ohm and the current draw of 800 ma Check with a test light that you have power through the solenoid. The round plug covers the oil pressure relief valve and its filter, the square plate with the blue printing covers the solenoid and the large steel moulded plate is a small oil sump and contains a gauze filter and covers the oil pump. 2 KB. large selection professional support fast delivery Magazine | Contact | Catalogues +44 (12 93) 84 72 00. The overdrive on my 56 100M was working perfectly and then out of nowhere it stopped. With a multimeter check resistance from the free end of the wire to G/box case which should be around 15 Ohms. e. The solenoid however isn't 'clicking' when trying to activate it from the wiper switch on the steering column. You can see where this is going I have four forward gears and reverse but no overdrive. I’m having problems with no oil pressure from my overdrive oil pump. We tried to give it direct power, bypassing the wiper switch, but still no sound from th I have been refurbishing and bench testing an overdrive gearbox from a donor car. The white/red stripe feeds the overdrive switch which after activating the overdrive solenoid goes to earth. Ignition off, no power at all. Being fed by a white wire, you should have power whenever the ignition switch is on, you should have power via your on/off switch, and you should have power through the overdrive isolation switch with the gearstick in In reply to # 4796010 by dickmoritz Go for a test drive and push the gearstick slightly to the right when in fourth gear and with overdrive switched on. If a thicker or second one of these is fitted both the solenoid body and the plunger will move out from the overdrive casing by the extra thickness. Once the engine/trans I just temporarily hooked up my 12v test light to the solenoid and went for a test drive Same problem. I acquired an overdrive LH Type transmission last year and was getting ready to attach it to engine, so was giving it a once over before attaching. If you have the shifter switch, the wiring is basically the same, but you have to wire one side of the switch to I bought all the stuff to bench test it— my father, who is otherwise a saint encouraged me to not test it. MGExp Winter Sale on now! Save on magnets & stickers in the MGExp Shop while supplies last The MG Experience. We tried to give it direct power, bypassing the wiper switch, but still no sound from th Both Type “A” and “J” but this one in my 1970 MGB has me beat well and truly. Posted by jewar . After experiencing a problem with my overdrive kicking out after approx 15 min of driving I am replacing o-rings in my LH type O/D and I have scoured the archives for tips etc on this task. John at Quantum Mechanics does not recommend using the vacuum solenoid, but provides a relay in his kit. That kit includes various parts that require removal and disassembly of the overdrive unit. Gearbox/Overdrive Removal. Weight: 0. It is a single switch on the dash as shown in the attachment. . Offline. The solenoid assembly requires three O-rings – change all three. I bought about 2 feet of 3/4 Make sure you test all switches and clean and service OD unit. I bought all the stuff to bench test it— my father, who is otherwise a saint encouraged me to not test it. Topic List Forum List Newer Older Start New Topic. We tried to give it direct power, bypassing the wiper switch, but still no sound from th MGB overdrive issue. I'm installing an overdrive in a '63 MGB and have a harness that connects to the solenoid and the overdrive interlock switch and runs up to the firewall connecting to the relay. Feedback + Email . Clean up the copper If there is power to the solenoid, and it has enough grunt in the above test, then do a hydraulic pressure test. Now I'm ready to take a look at the solenoid. Overdrive options for an MGB fall into 3 types. Not sure if it's electrical or a mechanical fault. It constantly jumps in en out, while driving in 4e gear. Topic Creator (OP) Dec 31, 2021 07:11 AM. Question #1) Wondering if it is the solenoid and I have a spare. My mechanic says it isn’t the electric switch but a part in the transmission and I have the same question as Don. These overdrives allowed overdrive in both third and fourth gears. I could get I just converted my '73 B GT to overdrive by picking up a used tranny that was equipped with one. MG MGB Technical - Testing overdrive solenoid While the body is away being painted I am looking at the engine and gearbox from my 1971 B roadster. Order your Overdrive Solenoid - LH Type - 37H1934 ⛽ Low prices and fast, worldwide delivery British car experts ♚ Call ☎ 01522 568000 or ☎ 1-855-746-2767. Overdrive Solenoid oil leak #1. Anything that Part 1 of 3 showing how to repair your overdrive when it won't fully engage. The wires from the switch in the knob down to the solenoid are subject to fatigue breaking from being bent back and forth as the shifter is moved, so first action would be to take the shifter apart and check that the switch in Order your Overdrive Solenoid - LH Type - 37H1934 ⛽ Low prices and fast, worldwide delivery British car experts ♚ Call ☎ 01522 568000 or ☎ 1-855-746-2767. overdrive. After I installed engine assembly the overdrive is not engaging. JPG 72. It is currently on an engine stand. Disconnecting either wire at the switch will prevent power from reaching the overdrive unit Dick In reply to # 4575256 by Denwhit Hi In reply to # 4796010 by dickmoritz Go for a test drive and push the gearstick slightly to the right when in fourth gear and with overdrive switched on. Product Code: 37H1935 MGB Overdrive rear oil seal 4 synchro. If that's ok the next item is the overdrive solenoid which is accessible from underneath the car. and then on to the overdrive solenoid. Simplified installation of overdrive wiring. To my knowledge the LH solenoid has just one Overdrive Maintenance. The workshop manual covers hydraulic faults well and describes how to go I've been doing the long, tedious work of refurbishing an OD unit (later LH style) to be put in my B. Was this post helpful or interesting? Yes No Thank. Posted by Woodypear . I've got the one in the Haynes manual but it's connect the other side of the lock-out switch to the solenoid and you're good to go. Click here to add a discussion for this item. If you want to service the overdrive with the unit still in the car, I suggest you buy and replace the filter/screen, the three o-rings and the square gasket on the solenoid assembly, and the two o-rings on the pressure valve. 1969 MGB Roadster 2020 MG HS Exclusive 2007 Mercedes SLK Plus 34 other cars since 1965. It is bolted to a 1970 (probably original to the rusted-out 1970 body) overdrive transmission - all new clutch components including flywheel, new front/rear seals and I disassembled/cleaned the OD solenoid, replaced its O rings, replaced the little screen thing, made VERY sure I didn't lose the little steel balls and properly filled with new 20 Double check the oil-level, then test-drive the car and check for leaks. Re: They are taking it out on test drives to ascertain the problem exactly. COIL FOR OVERDRIVE SOLENOID. As the gearbox is out of You can do a quick check of oil pressure/flow by supporting the car safely and level, and with the solenoid removed and a catch pan underneath, briefly run the car in overdrive and watch for a flow of oil out of the solenoid Overdrive Gearbox, TROUBLE SHOOTING - GT-308. www MGB overdrive (1974 model) OVERDRIVE SEAL AND GASKET KIT. The solenoid is not moving the solenoid Hi, I have an mgb gt 1979 with overdrive. For fitting instructions order 327500. Couldn't get reverse to engage. Product Code: NKC39A Both Type “A” and “J” but this one in my 1970 MGB has me beat well and truly. I could not get the solenoid to make any noise when hooked up to power and grounded. Checking power to solenoid and cleaning up the various parts of the overdrive to try and get it working#MGB I did test the electrical circuit by inserting my 12v test probe thru the insulation on the wire near the solenoid - other end earthed - switch is working fine. In overdrive Blue label signifies rubber bumper (1975 to 1980) LH MGB overdrive - DAM1362E; Red label signifies MGB GT V8 LH overdrive - 22B687E; Green label signifies MGC LH overdrive - 22B397E; An LH Overdrive viewed from below, note the printed ID plate held on by four screws that also secures the internal solenoid. Blue label overdrives are geared for speedometers rated at 1000 TPM. I & test switch & lamp gp gp gp reverse lights & switch gn g gn † wip er/ ash switch gk gk overdrive solenoid transmission interlock switch fuel pump w y yr yp w † overdrive on - off switch lh door switch p wg p p p p p p pw pw trunk water temperature speedometer tachometer oil pressure 1 2 5 3 diagram 10 - 70/71 mgb from bentley Buy spare parts for "Overdrive - D-type outer" of MGB (1962-1980). MGB 1975, Overdrive engage and disengage properly for the first 5 min of driving the car. Start the engine and place the gearbox in the fourth gear position. You say you're getting no power to the solenoid under any conditions. A freewheeling clutch can allow the engine to return to idle while the car is still running down the highway at 60 mph. If it does, check for power at the solenoid. If you put a magnet over the solenoid while engaged, you can feel it move— that part I’m confident is MGB_LH_Overdrive. If you would like a response, please supply your MGB: Gearbox & Driveshaft: Late Type LH Overdrive 1968-80 : 98: GASKET KIT: 1968-80: 1: I just converted my '73 B GT to overdrive by picking up a used tranny that was equipped with one. In reply to # 4381981 by Capt Bob Best person to ask is transmission Zen Master Dick Moritz. It should click when energised. Vic Butler Posts: 811 Joined: Wed Dec 21, 2016 6:07 pm Forename: Vic Surname: Butler The likely causes for an overdrive cycling in and out are a faulty overdrive inhibitor switch, a low oil level in the gearbox, an ageing seal causing an oil pressure leak, a faulty seating for the valve ball bearing, a faulty multi-function stalk switch operating the overdrive or an electrical fault related to the solenoid. The Moss Motors web site has a video with Kelvin showing how to test a solenoid. What I can tell you is when the engine and transmission were out they replaced the overdrive filter, the solenoid gasket and the inhibitor switch. About a quart came out the drain plug. I have a 1974 MGB-GT. 5 MGB-GT Quick question. switch out of the car and check its operation with a test meter. Fortunately mine was working fine before i took it out with the engine – Hope it still does 🤞 when I’ve got it back in. I wired the knob switch to a relay and the fused power side of the relay to the 3 4 selector switch on the transmission and then on to the solenoid. Oil level is OK. It worked before the car was laid up for winter but was slow engaging (there was a short delay after switching it on). If no power, your problem is electrical, which is the most common issue and easiest to fix. When I moved the gear lever from the 1-2 plane to the 3-4 plane I expected to hear the solenoid click, but it John Twist explains the operation of the various overdrive circuits for the 1968 → 1980 MGB/MGC. I added a dash indicator light in parallel to the solenoid connection so I know when power is going to the solenoid. Maker of BHH558 carb and choke bracket for MGB cars fitted with the SU In overdrive-overdrive does not work: Test for an electrical problem by piercing the solenoid wire with your test light with the ignition on, the overdrive switch on, and the gear lever should be hot. Removal or vacuum switch will make this overdrive more of a manual 5 gear. A low level. 5 MGB-GT In overdrive – overdrive does not work: Test for an electrical problem by piercing the solenoid wire with your test light, ignition on, overdrive switch ON, gear lever in 4th. Re: Overdrive solenoid confirmation question #5. Disconnect the (usually) orange wire bullet connector wire coming out of the overdrive solenoid. Log In | Register; MG Spares. This could be a fault on my unit which needs attention - I just don't know but it is a point worth remembering when test driving a prospective purchase! Later models of MGB have the overdrive switch built into the top of the gearshift knob. Road My '73 MGB GT trans has been pulled and has been disassembled on my mechanic's bench. Sorry no step by step this time. To test you need to completely assemble the overdrive solenoid assembly and manually move the plunger down flush with the surrounding material of the solenoid base plate. -- All the things you need to access are directly on the bottom of the overdrive. My wife has a 1977 MGB w/ overdrive. When testing, you may or may not hear a click when powering the solenoid. Hello all- I recently bought an overdrive for my car, and have started preparing it for testing and install. Overdrive solenoid confirmation question. Connect this power to either terminal of your new switch. The kit contains 11 o rings of various sizes. I did test the electrical circuit by inserting my 12v test probe thru the insulation on the wire near the solenoid - other end earthed - switch is working fine. Then if you ground the solenoid housing and apply 12 volts to the lead wire for the coil, the plunger should snap upward. Engine; Cooling; Fuel; Clutch, Gearbox, Axle solenoid, LH type overdrive; Overdrive - 4 Synchromesh - "LH" Type. MGB. In overdrive – overdrive freewheels on deceleration: In this condition, the MGB will accelerate and run at constant speed. We did so by tapping into the line going to a switch on the overdrive. Thread starter Norton47; Are the wires going to the unit in the case for a solenoid? This all appears to be after (only closes the circuit when you press it) is the test switch for the lamp beside it, which is the NHTSA mandated warning light for brake system hydraulic pressure Quick question. Technical MGB discussion. Maybe a recon box and overdrive and new clutch in the ol’gal. Mike 1969 MGB GTV8 3. Brian Wyld Posts: 12 Joined: Tue Aug 11, 2015 9:27 pm Forename: Brian Surname: Wyld MGCC Member: Yes. The solenoid is getting 12. Make sure you hook up the od solenoid and od lockout wires at the transmission before you install it. If not, test the circuit, connection to connection, The problem is most often the 3rd/4th lockout switch. Attachments: IMG_3620. csn cause overdrive engagement problems. Suggest that you first test the reverse light and 3rd/4th lockout switches on the OD gearbox. Woodypear Roger Sharpe. The outward symptom of a bigger issue was that the operating lever slipped on the operating shaft. 1974 MGB “I’m not arguing Go for a test drive, turn on the overdrive, On my way back from MG2017 my overdrive stopped working,no slipping in and out,just stopped. took the solenoid out old and some rust ,cleaned it up but not sure how to test it with a volt meter? any help would be appreciated Tom Now the overdrive switch on the dash is in the "off" position and has no effect when using it, but when driving the car up. PS2 Next to this click there is another method to test electrical solenoid continuity: This afternoon I thought I would check the overdrive (LH type) and applied 12v to the yellow/red wire with the negative from the battery connected to the gearbox case. All this cost around £80. Oil pressure and flow that actuates the cone clutch is controlled by an electric solenoid valve which presses a little steel ball against free. Posted by Brazzle99 . If it’s more than 20ohms, remove the solenoid by taking the square plate off. There are 3 or 4 switches in the wiring to get your overdrive to engage. The pump was sticking when I initially pulled it out, so I polished it and cleaned it before I r I just converted my '73 B GT to overdrive by picking up a used tranny that was equipped with one. If you put a magnet over the solenoid while engaged, you can feel it move— that part I’m confident is I received my overdrive o ring kit and I'm about to start the service work on the overdrive. The manual No test will suffice to eliminate the prejudice that the car must have a certain speed in order to achieve the o. T. A Test light or VOM will tell you if the yellow wire gets 12v+ with the ign on in 4th gear and O/D switch on. makes no difference to the oil pumping out Solenoid hole. In those early cars, you added an overdrive-specific wiring harness, available from Moss for about 25 bucks, to continue the wiring from there on to the backup light switch, the overdrive isolation switch, and the overdrive solenoid. Prior to the rebuild the overdrive was engaging. Breaks in the windings of the electromagnetic coil are not uncommon w TEST. Set your ohmmeter to the very lowest scale. I had the overdrive solenoid and the pump out while I replaced seals etc. Confirm with a test light or volt meter. Specifically the large o ring on the end of the solenoid. Deutsch Solenoid. Overdrive Solenoid #1. I was once helping a friend diagnose a non-functional overdrive in his MGB. So there has to be a switch inside the housing. What is the best way to test it to The best way of testing the circuit is with an ammeter - it should show about an amp when energised, a bit less when the alternator isn't charging. This is a series of videos from John Twist of University Motors Ltd. If not, test the circuit, switch to switch-but the problem is most often the 3/4 lockout switch. 9 Conversion. The good news on Friday was the discov I haven't had overdrive since going back on the road with my '71B after a long rebuild process. 4 posts • Page 1 of 1. d. I think I need to replace the o-rings in the solenoid and want to know if I need to drain the tranny to prevent a mouthful of oil when removing the solenoid. The reversing switch is an on/off for the two green The overdrive is stuck on in my 1979 MGB GT. Product number: 207732 MGB overdrive (1974 model) Posted by Denwhit . Also known a Laycock de Normanville overdrives. Is this an easy fix? Mark, when you disengage the overdrive do you have to lift off the throttle? You should do to operate the vacuum switch. Normally I have overdrive in both third and fourth. It will engage, drop out, then reengage, then drop out etc. All Classic British products are warrantied to be free from defects in material and workmanship for 2 years from the date of invoice. When I moved the gear lever from the 1-2 plane to the 3-4 plane I expected to hear the solenoid click, but it 1972 mgb gt blue label overdrive unity I believe my overdrive unit needs a good in place servicing/internal cleaning. Is this an easy fix? Suggest that you first test the reverse light and 3rd/4th lockout switches on the OD gearbox. Iv finally had a chance to test your latest suggestions. The picture shows the service plates. I also show how to test the sol It was intermittent for a few drives and then quit suddenly. You can't really hear the solenoid Trying to bench test the solenoid assembly is not always definitive. Library Article: Primer guide to MGB overdrive transmissions at The MG Experience. TR7 5 speed clutch disc Roller throw out bearing AP MGB pressure plate lighten flywheel to 18 lbs. All of these are the Laycock Engineering / GKN Laycock manufactured units based on the designs of Edgar De Normanville. This fits the 4 syncro laycock overdrives from 1968-1980. Help -think I've got a bad overdrive solenoid ? Thread starter bighealeysource; Start date Jun 23, 2011; MGB Help getting my 1980 MGB to pass CA smog test. The diagnosis: a failed washer (has four little tabs-can't find it on Moss exploded diagram) at the end of a shaft. Solenoid; Oil Pressure Relief Valve; Oil Pump; If you undertake overdrive maintenance as shown, pay incredibly close attention to the order of the various bits in disassembly and 1968 MGB GT LH overdrive The overdrive is not engaging. Generally it is more Overdrive solenoid questions. Post by Brian Wyld » Fri Nov 04, 2016 11:12 am. Since the winter break O/D hasn’t worked at all. The overdrive kind of worked, very sporadically, in the donor car when I first picked it up and drove down our country road back and forth. Fitment Info; Metrics # The MGB overdrive also has a clutch Dave Ramsbotham, who started this thread, doesn't give the age of the car I can't comment on the specifics of the early Overdrive (Type D) with the external solenoid or the later (Type LH) You need specialist equipment to do the test. Sign in to contact. Any help would be appreciated. Dec 29, 2013 There is an easy test for the 4th gear advance system. Clutch, overdrive, overdrive, clutch!!! What I don’t want to do is replace the Clutch and associated bits and bobs only to find it’s a bigger problem. Posted by 19661 . Lately it has been going into overdrive after activating the switch, but it kicks out and causes the car to sputter between the overdrive and 4th gear. Green wires have power when the key is on and green wires are fused. ” As others have suggested, refer to the "78 and Later" drawing from the Advance Autowire set. IF it is an overdrive are these fairly common, Triumphs don't seem to However you can use an ammeter, test-lamp or voltmeter to test the circuit and prove its continuity. Sounds good. Top. I have a black label LH overdrive. A good solenoid will test anywhere from about 15 ohms to about 80 +/-. Thanks. The factory never fused the overdrive circuit. To rule out the solenoid valve, I fabricated a test plate with a set screw. After the oil MGB & GT Forum. During one of my tests I really put my thumb pressure on the adjusting lever and it moved some more. I will offer what little knowledge I have on the subject. A lot more than that was pumped in, hard to say how much because it was pumping out of a 5 gallon bucket. This kit contains the overdrive filter, the “o”ring set and solinoid gasket. Blue label on the OD solenoid cover stamped “22/62005” 6. The overdrive on my 1979 MGB is not engaging. I replaced the solenoid and refreshed all the o-rings in the OD that are accessible with it still in the car. 1968 Overdrive Sequencer Relay These are the details of the MkI version. In overdrive – overdrive does not work: Test for an electrical problem by piercing the solenoid wire with your test light, ignition on, overdrive switch ON, gear lever in 4th. ” The fuse rating needs to be sufficient to cope with that surge current so Barrie recommends a I have a 1976 Mgb . I have a pressure gauge attached to overdrive and I can spin unit Checking overdrive. I thought I was in deep trouble. 26V when gears moved into 3 or 4th and it is showing 2. At Jim Legg's house I got under the car and checked for power at the solenoid but found none,so I ran a bypass wire to the solenoid but to no avail,which leads me to believe the lockout switch has failed,thus no power to the O/D. One coil has low-resistance, serves to move the plunger initially; the second coil has a higher resistance and serves to hold the plunger in place. KERBANG!!! In went the overdrive. The O/D did not work and I traced it to the solenoid. Check the fine wire mesh filter for drainage and fit a new gasket cover before replacing. overdrive , i blew everything clear including the oil channels above the valve with an air line and tested the connection to solenoid with a test light and all seems fine. I did replace the wire (14 Gauge) from the In this video, I determine that my 1977 MGB's Overdrive in the transmission wasn't working because of the oil pump (jammed). 77-80 cars had the overdrive operated by a switch in the top of the gearstick. Reply. Turn overdrive switch on. When I moved the gear lever from the 1-2 plane to the 3-4 plane I expected to hear the solenoid click, but it This afternoon I thought I would check the overdrive (LH type) and applied 12v to the yellow/red wire with the negative from the battery connected to the gearbox case. Hi, my 1980 mgb is having issues with the overdrive. 2) changed gearbox oil into 20W-50 penrite, Remove solenoid and test. Started by BN6_2197; Jan 30, 2023; Replies: 25; Austin Healey. this seems to have stopped working in the last month. shaped access cover 3. 6Ohms. There are many posts on the subject if you search on “overdrive wiring. 1000 TPM for OD and non-OD 7 Quick question. It was intermittent for a few drives and then quit suddenly. Clean and test again. I have correct and ample oil in gearbox and unit is out of car. That only tests it electrically of course, In the meantime, if you're looking for a quick and not too accurate test of the overdrive, you could bench test it and, after halting the spinning of the gearbox, but with the solenoid still powered, you could remove the plug or In overdrive – overdrive does not work: Test for an electrical problem by piercing the solenoid wire with your test light, ignition on, overdrive switch ON, gear lever in 4th. Right up front I give you this warning: The MGB overdrive system consists of a manual switch that the driver can use when they want overdrive to be engaged, and a gearbox over-ride switch that prevents overdrive being engaged when it shouldn't be, even if the driver has the manual switch on. The overdrive should be inhibited from operation in any other gears than 3rd and 4th. When I bought my 1980 MGB GT a few years back, the guy selling it said "Don't put it in reverse with the overdrive switched on - you may get away with it once, but not twice". Refilled with same Does anybody out there have a simplified wiring diagram for the MGB overdrive circuit. EUNGELLA, QLD, Australia . 5. Started by JohnGone; Nov 21, 2022; Replies: 19; MG. Just put my Mk 2 1968 GT back together after fitting a new clutch. The solenoid wire In overdrive-overdrive does not work: Test for an electrical problem by piercing the solenoid wire with your test light with the ignition on, the overdrive switch on, and the gear I am a bit worried about my overdrive. When I moved the gear lever from the 1-2 plane to the 3-4 plane I expected to hear the solenoid click, but it The rubber bumper cars are fitted with a Laycock overdrive situated at the rear of the gearbox. OVERDRIVE SEAL AND GASKET KIT. First, I created the connection from the drill to the tranny. But NO HyD pressure registering on the dedicated gauge I purchased when screwed into the plunger port So to refresh My transmission, which is not overdrive, '70 RHD MGB; '11 LHD Nissan XTerra; '23 LHD Mazda Miata. A couple of weeks ago I changed the oil in the tranny. The MG Experience. Now overdrive not working. Last night John Twist and I went through all Checking power to solenoid and cleaning up the various parts of the overdrive to try and get it working#MGB This afternoon I thought I would check the overdrive (LH type) and applied 12v to the yellow/red wire with the negative from the battery connected to the gearbox case. If you would like a response, please supply your MGB: Gearbox & Driveshaft: Late Type LH Overdrive 1968-80 : 98: GASKET KIT: 1968-80: 1: The Longest in the Business. MGB How does on tell if an MGB has Overdrive. Phil Brauer Neosho, MO 1973 MGB; 1958 MGA; 1974. Many classics have passed The only test you can do easily is the solenoid. I am attempting to re-install the " Relief and low pressu Overdrive lockout switch - How to change. I removed the solenoid, pulled it apart and cleaned it thoroughly. ANSWER= Yes to oil being pumped out the solenoid bore with the car on jacks, running in 4th with OD cycled on & Off. I believe I remember that as how I first noticed the problem a few times. If not, test light with the ignition on, the overdrive switch on, and the gear lever in fourth. Use a 12 volt test light or volt meter to check for power coming to the solenoid. What is the best way to test it to see whether it is working properly? This could be a fault on my unit which needs attention - I just don't know but it is a point worth remembering when test driving a prospective purchase! Later models of MGB have the overdrive switch built into the top of the gearshift knob. Hope someone can help. The solenoid wire should be hot. Don Hayter in his 'MGB Story' writes that the American Government Department bought and tested a 1975 MGB and used it in a 5mph barrier test which it failed, to such an extent that the engine had moved forward during impact and the fan had damaged the radiator, potentially causing a leak, despite similar factory testing not showing up the problem. Joined 13 years ago. Would be grateful if anyone has had a similar problem and was able to solve it. Overdrive - LH-Type LH type without ignition relay LH type with ignition relay - UK LH type with ignition relay - North America Location of gearbox switch Hover over a wire to confirm the colour LH type without ignition relay (68-76 and V8): On cars with the dash-mounted manual switch to protect the most wiring insert the fuse in the white wire at A where it connects to the back of We put the car up on his lift and checked to make sure the electronics were working. Unscrew the square cover and withdraw the solenoid and check the ‘O’ rings are in good condition. not yet installed in my MGB: Discussions Currently there are no discussions available for this item. Model (Site) Category Schematic Key Name Application Qty; Jaguar Early Sedans: Gearbox & Driveshaft "G"-Type Overdrive : 24: SOLENOID: Early Sedan: 1: MGB: Gearbox & Driveshaft: Early Type D Overdrive 1962-67 : 7: SOLENOID: 1962-67: 1: MGB: Gearbox & Driveshaft, Relays, Switches & Miscellaneous It should be wired in parallel with the solenoid (fit a double female bullet at the solenoid plug) and will provide you with complete information about if and when power is getting to the solenoid. In this video we will ru Using a drill to drive an MGB overdrive transmission to check the solenoid operation. 9 Conversion, 1977 Triumph Dolomite 1850HL, This afternoon I thought I would check the overdrive (LH type) and applied 12v to the yellow/red wire with the negative from the battery connected to the gearbox case. The solenoid assembly is behind the blue (I think blue) plate with four screws in it and the small wire coming out the side - be careful not to yank on the wire lest you damage it! You can test the entire circuit easily with a test light or volt/ohmmeter, from the switch through the overdrive isolation switch and on to the solenoid. Checking overdrive. With the test plate in place, car in 4th gear running about 40 mph, I lightly tightened the set screw to manually close the solenoid plunger. I have checked the wiring and I'm getting 12v to the solenoid itself with overdrive switch on in 3/4th gear so I'm happy that both the overdrive switch and overdrive gear switch are working. Blue label on the OD I recently got a 1980 MGB roadster and the overdrive does not engage. Additional information. If the operation of the overdrive is normal, then remove the lockout switch and remove one of the (usually red) fiber washers from under the switch and re-install. The overdrive has not worked for a couple of years ,current is good . If not, test the circuit, connection to connection, I’ve check power to solenoid from switch, all ok and replaced solenoid which is functioning. Will I have to remove the solenoid and clean it? Overdrive is a mystery to me and I am loath to disturb it. 4. WillR Jedi Warrior. I can engage/disengage the OD like 10-15 times in a row no problem. The test plate basically turns the solenoid valve into a manual valve for diagnostic purposes. to activate. English. The store will not work correctly in the case when cookies are disabled. Also you need several special tools (8 I think) to dismantle and rebuild the overdrive, and even then you can't test it out of the car at home. The problem: failure to shift into 2nd gear when moving. The overdrive slips in and out weather the switch is engaged or not. Got underneath and determined that there was no power getting to the solenoid, then tested the solenoid itself by simply having someone hold one end of a wire to the batter terminal, the other to the solenoid itself, and got a satisfying 'clunk'. i took the car out for a test drive and the overdrive works albeit slower to engage and disengage than before. Dirty hydraulic components or, more commonly, a worn sliding member (cone clutch) causes this. When I moved the gear lever from the 1-2 plane to the 3-4 plane I expected to hear the solenoid click, but it First, check the oil level in the gearbox. The hydraulic pressure test shown in the workshop manual is best done with sufficient hose length to attach it to the quarter light window so that the car can be driven. It slipped on the shaft I believe because of extreme oil pressure. Very early blue label units allowed overdrive in both third and fourth gears. Model (Site) Category Schematic Key Name Application Qty; MGB: Gearbox & Driveshaft: Late Type LH Overdrive 1968-80 : 80: VALVE ASS'Y. Also the diagram is not clear as to the exact location of several of the o rings. K. Then run a wire from the other terminal of this new switch to either terminal of the overdrive switch on the gearbox, and then run another wire from the other terminal of the gearbox overdrive switch to the solenoid. If it has power all the time, with key on and the switch in the Off position, then the switch is feeding power to the overdrive all the time and the switch is faulty. Sign In Create Account. ignition on, power to the solenoid in 3rd & 4th gear only. Eventually it seemed like the overdrive would drop in MGB & GT Forum. Hi, I have an mgb gt 1979 with overdrive. I am doing a bench test of my new to me overdrive transmission before I install it into my car. In overdrive-overdrive does not work: Open the bottom of the overdrive unit and clean all the parts-the solenoid, Mark, when you disengage the overdrive do you have to lift off the throttle? You should do to operate the vacuum switch. If not, test the circuit, connection to connection, I am guessing here but I think it is possible that the solenoid failed and it stuck in overdrive. Eventually it seemed like the overdrive would drop in 28 ohms is fine. But it just won’t engage in 3/4th. You may or may not have such a MGB Transmission - This video shows work on the Laycock overdrive unit. LH blue label units were used from 75/76 through the end of production. I am getting 12 volts to the solenoid. When I moved the gear lever from the 1-2 plane to the 3-4 plane I expected to hear the solenoid click, but it I've been doing the long, tedious work of refurbishing an OD unit (later LH style) to be put in my B. Page 12. I have been lurking for quite some time on the site reading and learning as much as I could in regards to the MGB overdrive. I thought some folks might want to see how I performed the test and what my setup was. Had to refer to the wiring diagram to identify which of the 3 wires did what. I got this trans/OD unit out of a '80 MGB, and have plans to install it in my '76 MGB. Posted by trymes . When I moved the gear lever from the 1-2 plane to the 3-4 plane I expected to hear the solenoid click, but it The Longest in the Business. Started by thomasd; Dec 19, 2022; TR4/4A TR4 Overdrive Solenoid. 3rd Time to re test the electrics. As far as I know the O/D worked the last time the car was used, but that was probably 5 years ago. Always on (switch always closed, meter reads zero ohms) would mean it's possible to power the solenoid up in 1st, 2nd and reverse if you hit the switch in the cabin Hi, my 1980 mgb is having issues with the overdrive. My overdrive is up and functioning again. 0. Before the change the OD had not been engaging. x. The ball atop the solenoid is 3/16, which is 6/32. You can easily test this by using a test light or meter at the wire going to the overdrive solenoid. If any one of those has failed your overdrive won't engage. Then after a little fiddling the solenoid would click with ignition on and manual switch on and gear selector in 4th gear. We tried to give it direct power, bypassing the wiper switch, but still no sound from th. Stripped and cleaned Solenoid, New o rings, gaskets, filters. The Moss diagram only shows 7. I now find that the electrics are as they should be i. The ball for the non-return valve is 7/32, just a skinch larger than the solenoid ball, To rule out the solenoid valve, I fabricated a test plate with a set screw. If that's ok remove the switch and with it switched on, check for battery voltage on both terminals. When I moved the gear lever from the 1-2 plane to the 3-4 plane I expected to hear the solenoid click, but it Even if the electrical tests are good, the solenoid plunger could still be jammed. We did connect a test pressure gauge to the test port on the OD and pressure changed in line with specification each time the switch was operated - this was done on a hoist with the rear wheels turning (rebuilder Overdrive Transmissions by Tom guide, but rather to assist in selecting the correct model overdrive transmission (or OD for short) for any given year MGB. An ammeter is best as it will show the actual current flowing in the circuit Hi, I have a 76 GT with an LH OD. Started by Alex My transmission, which is not overdrive, '70 RHD MGB; '11 LHD Nissan XTerra; '23 LHD Mazda Miata. This afternoon I thought I would check the overdrive (LH type) and applied 12v to the yellow/red wire with the negative from the battery connected to the gearbox case. I clicked the stalk inside the car and the test-light would light up in 3rd and 4th gear, which I understood to be correct. cjdeq kekndoxa oetnvu grci zki trab oec nrgtw xmwsvg xuwp