John McCormack Posted July 3, 2019 Report Share Posted July 3, 2019 My long door TR2 today passed its roadworthy (MOT) with flying colours. However, the overdrive wasn't working after I adjusted it so I asked the workshop to test it for me. It still doesn't work. The pump pressure is good and the solenoid is working normally. When engaged the OD seems to work, the output shaft moves slightly indicating something is happening internally, but the revs don't change. He doesn't know what is wrong with it so it looks like out with the box and send it to the OD specialist. He isn't available for a couple of months so I can use the car without the OD until then. I want to get the interior finished and can't really do so if the box has to come out again I thought I would see if anybody here has experienced these symptoms as an early fix without removing the box would be great. Quote Link to post Share on other sites
RogerH Posted July 3, 2019 Report Share Posted July 3, 2019 Hi John, assuming the solenoid works, the loom and switches are good, there is enough oil etc etc then it may simply be a matter of re-rigging the solenoid and shaft. Slacken off the solenoid clamp. Move the rigging arm to align with the rigging hole (use a drill ect to check alignment) and then move it the arm a very very small amount beyond the rigging hole (remove the drill first) - then tighten the solenoid clamp. Roger Quote Link to post Share on other sites
John McCormack Posted July 3, 2019 Author Report Share Posted July 3, 2019 (edited) Thanks Roger. I adjusted it like that before I took it to him. He then adjusted it although I didn’t question him in detail exactly how he adjusted it. It is possible but not likely it still isn’t adjusted properly. I doubt it because he has been a Triumph specialist since the 1960s. If I put the rear end on axle stands, run it in top with the clamp loose and pull the actuating lever on the right side of the OD until it either works or reaches full movement, will it do any damage? Edited July 3, 2019 by John McCormack Quote Link to post Share on other sites
RogerH Posted July 3, 2019 Report Share Posted July 3, 2019 Hi John, that would work but be VERY VERY careful. Make sure the front wheels are well chocked. 2500rpm - advance the lever and it should drop in and reduces revs to near 2000rpm. Be careful Roger Quote Link to post Share on other sites
TwinCamJohn Posted July 3, 2019 Report Share Posted July 3, 2019 It was suggested to me that testing an o/d like that would not work as there was no (I can't find the right word) weight of the car. In fact I had re set mine and thought it was still not working as I tested it as above. On the road it worked fine. Quote Link to post Share on other sites
John McCormack Posted July 3, 2019 Author Report Share Posted July 3, 2019 28 minutes ago, TwinCamJohn said: It was suggested to me that testing an o/d like that would not work as there was no (I can't find the right word) weight of the car. In fact I had re set mine and thought it was still not working as I tested it as above. On the road it worked fine. Interesting. There are no switches or sensors to cause this that I am aware of. I have often engaged OD on my other TR2 with the car on stands. My concern is that operating the lever by hand may over extend the operating shaft beyond the point it operates the valve that lets the oil pressure through to the OD. I don't know enough about the OD internals to know if this could be a problem. The car will be on stands tomorrow when I go over to the workshop, I will see what the mechanic and I can do then. Quote Link to post Share on other sites
Graham Harris Posted July 3, 2019 Report Share Posted July 3, 2019 I don't think you will be able to operate the leaver by hand there is too much pressure, you could use multi grips or similar but be careful not to go too far, better to check the adjustment by the manual and it should work through the solinoid. Graham Quote Link to post Share on other sites
Hamish Posted July 3, 2019 Report Share Posted July 3, 2019 With the car on axles stands it is more likely that the speed will rise a bit rather than the revs drop when the overdrive cuts in. I tried it when I had my issues. Quote Link to post Share on other sites
TwinCamJohn Posted July 3, 2019 Report Share Posted July 3, 2019 I have just found the word I wanted !! Running on axle stands there will be no load and that is why the o/d will probably not engage. Quote Link to post Share on other sites
Lebro Posted July 3, 2019 Report Share Posted July 3, 2019 It will engage, but as said above you may not notice because the revs will stay the same, but the wheels will spin faster. Bob. Quote Link to post Share on other sites
John Morrison Posted July 3, 2019 Report Share Posted July 3, 2019 So the revs don't drop, the speedo goes up. Safest way to look at this is remove the prop at the gearbox, then you are not spinning that, the axle or the wheels. Then using the 11/64 th drill in the alignment hole, AS A START, But lean on the drill as you clamp up. To counter the fact that these holes are 60 odd years old, and likely ovalish still no joy? Next you want to remove the operating valve, (7/16) nut on top or the unit, allow for some oil seepage. With a magnet 1/4 inch is great , pull the spring, ball bearing and valve, clean the valve, blow through the hole, replace the ball bearing for a new one, critical this, seat with a mild drift, ally is perfect, and gentle taps, reassemble and reset alignment. Changing the ball bearing for new, and seating on the operating valve are critical processes in sorting the operating valve, then with the prop shaft still disconnected, if the o/d works speedo reading will rise, though in truth you will sense the gearbox jump. All this is in the w/s manual, and all works, ask me how I know? John. Quote Link to post Share on other sites
Hamish Posted July 3, 2019 Report Share Posted July 3, 2019 (edited) 8 minutes ago, John Morrison said: So the revs don't drop, the speedo goes up. John. When on axle stands without road resistance yes. On the road we see the revs drop until the car picks up momentum Edited July 3, 2019 by Hamish Quote Link to post Share on other sites
Rodbr Posted July 4, 2019 Report Share Posted July 4, 2019 FWIW when I had my three overdrive gearboxes rebuilt I was asked about what pressure setting i wanted. The options were standard around 450psi, fast road (a bit more snappy) around 600psi and full race (snap halfshafts) God knows.rebuild the box every season. I opted for the mid range as I like the overdrive to talk to me. After initial problems with burn out of solenoids caused by failure of the solenoid to switch to holding current Duff push switch in the heads. I now have an overload circuit box which sits there working and protects the solenoids. The overdrive either works or it doesn't meaning there is an issue with the electrical circuit butr the solenoid can never be overload and burnt out. I do not consider them to be a consumable. This system is foolproof and works amazingly well. I would suspect that the pressure on your internal pump is not set correctly. Even with the lowest setting you do feel a faint surge as the overdrive kicks in. Rod Quote Link to post Share on other sites
RogerH Posted July 4, 2019 Report Share Posted July 4, 2019 Hi Rod, inside the solenoid there is a little change over switch (pull in - hold in coils). This switch will fail eventually. Roger Quote Link to post Share on other sites
Rodbr Posted July 4, 2019 Report Share Posted July 4, 2019 Hi Roger, Fully aware of this but I had two new ones fail in one year, not a good situation? If this switch fails or sticks it will go into meltdown. It is a nasty primitive system as it it just a small floating pin that moves to break a set of points like a distributer. Quote Link to post Share on other sites
John McCormack Posted July 4, 2019 Author Report Share Posted July 4, 2019 I worked with the mechanic today going over the car. He pointed out a few minor details I hadn't picked up. He had driven the car for about 6 miles and was delighted with it. The OD. We had the car on big workshop stands both ends so could run it safely. OD oil pressure is very good, no problem there. When the OD is engaged the output flange moves slightly as the OD does its stuff. The normal gear noises in the box also change indicating the OD has engaged. However, no change in output shaft revs. We physically moved the operating lever to make sure it was fully home without any change. The OD internals are working but the OD isn't engaging. This could be because it has been assembled incorrectly when the box was overhauled. The mechanic, who didn't do the box, rebuild, can't identify the cause. He rang the OD specialist, unfortunately in another state, who can't pick it from the symptoms. Unfortunately the gearbox will have to come out and be set up on a bench. Looking at it in a positive light 28 months ago I bought a pile of bits home in two trailer loads. It is now a 'new' long door TR2 that drives very nicely. The interior isn't in it yet so the box can come out and go back in without too much trouble. The OD can be repaired while I do some finishing touches to the car. Once the OD is done the interior and weather gear can be completed. All will be good. Quote Link to post Share on other sites
Kiwifrog Posted July 4, 2019 Report Share Posted July 4, 2019 John If you want to learn a bit about the operation of your overdrive you can download the original triumph manual from Tony Drews webpage https://www.tonydrews.com/Overdrive/A-type OD manual.pdf link to his webpage https://www.tonydrews.com cheers Alan Quote Link to post Share on other sites
iain Posted July 5, 2019 Report Share Posted July 5, 2019 Alan Many thanks for posting this link, very useful Iain Quote Link to post Share on other sites
RogerH Posted July 5, 2019 Report Share Posted July 5, 2019 There is a lovely statement in the OD service manual Page 5 'Care and Lubrication' DO NOT USE EP oils So what do we now put in EP90. Roger Quote Link to post Share on other sites
Motorsport Mickey Posted July 5, 2019 Report Share Posted July 5, 2019 49 minutes ago, RogerH said: There is a lovely statement in the OD service manual Page 5 'Care and Lubrication' DO NOT USE EP oils So what do we now put in EP90. Roger I don’t, why would you ? Is that what ORS and other specialist recommend ? Mick Richards Quote Link to post Share on other sites
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