Welcome to our resource for MG Car Information.



TR parts and Triumph parts, TR bits, Triumph Car Spares and accessories are available for TR2, TR3, TR3A, TR4, TR4A, TR5, TR6, TR7, TR8, Spitfire and Stag and other TR models are available from British car spares and parts company LBCarCo.

Triumph TR6 - J-Type overdrive removal?

I had my J-Type overdrive overhauled by a transmission shop (familiar with J-Types) this winter and find that it won't disengage now that I've got in installed again in my TR6. I'm going to take it back to the shop again to have this fixed, but would like to know - in case the O/D has to come out - if it's possible to separate and remove the overdrive without removing the transmission. Has anyone on the BBS tried to do this?

Hauling that tranny out and putting it back again is no pleasant chore and I'd like to avoid that if possible.

Thanks much in advance.

1973 TR6
B. Lanoway

Brian, it sounds more like a wiring problem. I had the same thing happen to mine on reinstall, and discovered I had wired incorrectly. I can't give you advice, as I do not remember how it is wired, but worth double checking.
Pete Russell


There was a recent thread on oil selection for gearboxes with overdrive. At least one poster reported that using the originally recommended EP90 oil, his OD engaged but wouldn't disengage. I just replaced my clutch and had refilled the gearbox with EP 90 but drained and refilled it with Valvoline 20/50 racing oil based on the above mentioned thread.

Good luck.

75TR6 with type J OD
BJ Quartermaine

Brian-Before you remove the trans., try tapping on the brake ring. It is not unusual for the clutch to stick to the brake ring. An easy test to tell if the OD is disengaged is to put the car in neutral and attempt to push it backwards. If it won't move, the OD is engaged.
Berry Price
BTP Price

I want to thank everyone for their suggestions. In the end, I was able to fix the stuck overdrive without removing it from the car. As Berry Price suggested above, the solution was to rap on the external brake ring with a mallet. I had to go through the cycle of drive/engage/stop/hammer-the-ring-to-disengage five times to get the overdrive to fully work, but now everthing appears to be OK.

Thanks again for the advice,
B. Lanoway

Mr Price,as always,well done!

Thanks for the accolades! I am a graduate of the school of hard knocks-no pun intended. The first time my OD failed to release, it almost caused a heart attack as I had visions of having to disassemble it. After reading the trouble shooting section of a manual (Haynes?) a possible cause listed was the clutch stuck to the brake ring and the remedy was to whack it with a mallet or rod. My OD is slow to release and after reading the article on Quantum Mechanic's website, I may switch to 30wt or 20-50 racing oil as Don E. advised. As an after thought, I don't think it is possible to remove the OD with trans. in place.
Berry Price
BTP Price

I just took my od off of trans while in car. This was possible because I had cut tunnel in half to be able to get at that area. This is something everyone should do. cut aprox 14.5 " from front of tunnel. pop rivet a strip of plastic or aluminum to underside of front half to seal it.
greg waters

I don't know if he has mentioned it here,sorry ti hijack your thread Brian, Don E. has torn the 3 apart for a engine freshening and a body paint. Similar to a 50 year old male Drs. appt. Ouch

Hope I wasn't suffering from "Hoof in mouth disease" about it not being possible to remove the OD with the trans. in place. My experience has been with the A type
and if it was possible to remove it with the trans. in place, it would be impossible to replace it. Keeping the springs in place, lining up the splines, and the cam over the pump plunger would be very challenging. A types and trans. like to mate in the vertical position. J types might be different.
Berry Price
BTP Price

This thread was discussed between 01/05/2007 and 08/05/2007

Triumph TR6 index

This thread is from the archive. The Live Triumph TR6 BBS is active now.