Lord Flashart Posted July 4, 2015 Report Share Posted July 4, 2015 Gentlemen, Drove the TR yesterday and the overdrive just stopped working. I reversed out of the garage and realized that the switch was engaged when I changed to second gear. Then when up to speed I tried to re-engage the overdrive and now it won't work at all. When I got home I checked the wiring and electrically everything is in order, including the inhibit switches, so overdrive cannot have been engaged when I reversed. Tonight I pulled the covers off and had a poke around. The fluid level is correct and the only thing I can see is that the level on which the solonoid acts has no resistance to it all, when I fitted it to the car I could feel the pressure realising when this lever was pulled. Is there something that is likely to cause this? I've searched the archives and all the advice I can find is electrical or fluid level, both of which are correct. Paul Quote Link to post Share on other sites
AlanT Posted July 4, 2015 Report Share Posted July 4, 2015 (edited) The wonderful articles on the OD, from the "Buckeye" site, are down at present, it seems. If you PM me with an email address I can attach copies from my archive. I guess the operating valve is blocked. I hope so because this is easy. This series in also very good: http://vintagetriumphregister.org/maintain/TransRebuild/TranIntro.pdf Edited July 4, 2015 by AlanT Quote Link to post Share on other sites
Robert Price Posted July 4, 2015 Report Share Posted July 4, 2015 Had the same problem and it turned out to be a single wire strand on one of the column switch soldered connections which was shorting the switch. Rob Quote Link to post Share on other sites
RogerH Posted July 4, 2015 Report Share Posted July 4, 2015 HI Paul, just to clarify - When in 3rd/4th gear, ignition on, operating the Column OD switch - does the relay clunk in and the solenoid activate. Roger Quote Link to post Share on other sites
ctc77965o Posted July 4, 2015 Report Share Posted July 4, 2015 Hi Paul, With car stationary, ignition on, top gear selected - can you hear the click of the solenoid when you switch OD on?? If not, reach under the dash and waggle the wires on the relay.....if not not..is there 12V on the relay?? If all is good then I would just drive it more...overdrives are pretty bomb-proof...a little heat n exercise could well fix it.... dave Quote Link to post Share on other sites
Lord Flashart Posted July 4, 2015 Author Report Share Posted July 4, 2015 (edited) Cheers guys, It's not electrical!! I drove the car without the transmissions tunnel on and pulled the lever with my hand and it still didn't work! Paul Edited July 4, 2015 by Lord Flashart Quote Link to post Share on other sites
AlanT Posted July 4, 2015 Report Share Posted July 4, 2015 (edited) Apart from VTR and Buckeye, I also have the Laycock manual. If the "lever" feels wrong then the cross-shaft maybe does not lift the valve. It comes back to me that if the clamp gets loose, and the rod turns a bit, then the valve can drop past the end of the lever that lifts it. This does no harm and is not too hard to recover. You have to fish the valve back up. Edited July 4, 2015 by AlanT Quote Link to post Share on other sites
Lord Flashart Posted July 5, 2015 Author Report Share Posted July 5, 2015 Gentelmen, Had another look at the overdrive today and with the engine running and car in gear (wheels on jacks!) there is fluid flooding into the operating valve chamber, so I think the pump is probably ok, but I don't yet have a pressure gauge to confirm. The operating rod that normally connects to the solonoid still appears to have no resistance to it at all so I'm guessing that it's not connecting properly inside. Do any of the experts know if I can get to this from the side cover of the unit? I'm reluctant to pull the whole gearbox at this stage, but I will if I have to. Paul Quote Link to post Share on other sites
Chilliman Posted July 6, 2015 Report Share Posted July 6, 2015 Do any of the experts know if I can get to this from the side cover of the unit? Unfortunately not Paul. The only important attachment on that rod is at the other side of the unit to the side cover (inside) - Basically there is a small lever held on the shaft by a pin, that lever then pushes up the operating valve assembly when the solenoid is operated causing the reserve of pressurised fluid in the accumulator to be released and the pistons operated. There should always be resistance to the movement on that rod when rotated as there is a constant spring pressure acting against it at the top of the operating valve. Before doing anything drastic, remove the operating valve plug and check to make sure the valve hasn't dropped down off the operating lever - if it has it would explain what you are describing but would also mean box out as the pins possibly broken? Quote Link to post Share on other sites
Lord Flashart Posted July 6, 2015 Author Report Share Posted July 6, 2015 Thanks chilliman, That's what I suspected! I'm going to put my non overdrive box back in so I can still drive the car. I might leave it that way, the overdrive just seems like something else to go wrong. Paul Quote Link to post Share on other sites
RogerH Posted July 6, 2015 Report Share Posted July 6, 2015 Hi Paul, removing/fitting GB's isn't funny. However OD's can and do work reliably once sorted. Don't give up. Roger Quote Link to post Share on other sites
littlejim Posted July 6, 2015 Report Share Posted July 6, 2015 For what it is worth on my 4A the '"book" procedure for setting the O/drive didn't work. I had to put it up on jack stands and loosen the clamp on the shaft that goes through the gear box and clamp it where the solenoid actually engaged O/drive. The 'pin through the hole in the lever on the opposite side' method didn't work. The hole in the lever was several mms above the decreed position when i got it to work properly. has continued working like a charm. Dunno if this has any relevance to your situation. Quote Link to post Share on other sites
Chilliman Posted July 6, 2015 Report Share Posted July 6, 2015 However OD's can and do work reliably once sorted. Don't give up. There are as many polarised views on overdrives as there are best oil types for the gearbox but for my money it is a splendid piece of kit that I wouldn't want to be without, so don't write it off, like Roger says - once they're working as they should they can be very reliable and they will add significantly to the overall driving enjoyment. They are also not that complicated to work on so don't be afraid, - if you do decide to go for it yourself - I've got a load of pics that would help. Quote Link to post Share on other sites
Lord Flashart Posted July 7, 2015 Author Report Share Posted July 7, 2015 Cheers chaps, I'll pull the gearbox (easy!) and then I'll need to separate the overdrive from the main housing to see what's going on with the actuation switch. Is there anything I need to know about separating the units? Does it just unbolt or is it going to spring to bits when I separate them!! Paul Quote Link to post Share on other sites
Chilliman Posted July 7, 2015 Report Share Posted July 7, 2015 It is under pressure of the O/D clutch springs but you will find the two centre studs holding the box & O/D casing together are a lot longer than the others and allow you to slowly release all the pressure by undoing them gradually and evenly, be aware that the springs themselves are of two different lengths according to where they sit (inner or outer ring). Quote Link to post Share on other sites
BlueTR3A-5EKT Posted July 7, 2015 Report Share Posted July 7, 2015 When going back together do a 'dry run' without the springs and cam to ensure the splines are all in line - it should just drop into place with the overdrive held in the vice and the gearbox dropping on vertically. Fail to align the splines in the overdrive and you will definitely crack the adaptor plate when you start tightening the nuts/studs. - been there, done that. The manual says use dummy mainshaft to align splines - that is effectively what you are doing, using your gearbox as the dummy shaft. Peter W Buckeye Links - Just click through from the menu list http://www.buckeyetriumphs.org/technical/AOD/ http://www.buckeyetriumphs.org/technical/AOD/AOD1/ http://www.buckeyetriumphs.org/technical/AOD/AOD1/AOD1.htm Quote Link to post Share on other sites
sadman Posted July 7, 2015 Report Share Posted July 7, 2015 Mine didn't work for quite a long time, & thought I had the adjustment right, oil level ok, checked adjustment re workshop manual, solenoid working ok, took it to Rugby overdrive spares, 7 minutes on the ramp, sorted! so was the wallet, (he actually did it for goodwill) I'll gladly use him again Doug Quote Link to post Share on other sites
Lord Flashart Posted July 7, 2015 Author Report Share Posted July 7, 2015 Cheers, I'll hopefully get to it next week sometime. Doug, I'd love to just take it to Rugby overdrive services but since they are around 5000 miles away, it wouldn't be a cheap trip!! Paul Quote Link to post Share on other sites
sadman Posted July 8, 2015 Report Share Posted July 8, 2015 Hi Paul, I suppose echoing earlier comments re workshop manuals accuracy. (also me not paying any attention to where you are!) Regards, Doug Quote Link to post Share on other sites
Lord Flashart Posted July 20, 2015 Author Report Share Posted July 20, 2015 (edited) Chaps, So I've got the 'box on the bench. I'll report back if I manage to mend it! Paul Edited July 20, 2015 by Lord Flashart Quote Link to post Share on other sites
Lord Flashart Posted July 20, 2015 Author Report Share Posted July 20, 2015 I've got it apart and found the problem. The activation rid has fell off the cam and bent slightly. Should be an easy fix! One question though, predictably the springs all fell out on disassembly. There are two lengths, anyone know which way they go back in? Paul Quote Link to post Share on other sites
Chilliman Posted July 20, 2015 Report Share Posted July 20, 2015 Short ones on the inner rods and longest springs on outer rods, you may find the ends of the springs painted, red on short, yellow on long. Quote Link to post Share on other sites
stargazergs Posted July 20, 2015 Report Share Posted July 20, 2015 Hi Paul If your stuck it may be worth contacting Len Drake at Drakes British Motors in Kelowna BC, if he can't help himself he may know a man who can. I bought my 4a from them and they were very helpful with the whole process. regards Gavin http://www.drakesbritishmotors.com/forsale-triumphs.htm Quote Link to post Share on other sites
Lord Flashart Posted July 20, 2015 Author Report Share Posted July 20, 2015 Cheers guys. I've found an online manual which is going to help also. Gavin, I'm just down the road from drakes and know them well. The car came from them a few years ago. They don't really have any mechanical knowledge, other than basic stuff! Cheers Paul Quote Link to post Share on other sites
Lord Flashart Posted August 7, 2015 Author Report Share Posted August 7, 2015 I replaced the actuation rod and put it all back together and fitted the unit to the car. My car is still a four speed! Any suggestions? There is fluid in the box and the solenoid is working fine. Again, if I disconnect the solonoid and move the levers but hand while driving, there is still nothing. I'm just going to drive it for now anyway as the season here is ticking away and if the car is off the road for another month awaiting parts I won't be able to drive it until next year. I'm starting to regret even laying eyes on this damn overdrive, car drove for years just fine without one. What I'm starting to question is the wisdom of driving an old British car this far away from any support. Cheers in advance. Paul Quote Link to post Share on other sites
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