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J-Type overdrive for sale on CL


Jedi Knight
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J-Type Overdrive on CL

Is this from a Triumph or a Volvo, and, if the latter, is it easy to adapt to the TR6? I'm guessing by the serial # that it IS from a Volvo. And how does it compare to the A-Type (from any personal experience)?

Also found today on CL, a supercharger.


Great Pumpkin - R.I.P
Has the wrong speedo fitting for a TR, so Volvo seems likely to me. Check out the Quantum Mechanics web site, he sells a conversion kit. Don't forget, you'll have to disassemble the unit to change the speedo gear (which of course I think is a Good Idea anyway).

I have an A-type in the TR3, J-type in both Stags. IMO the J-type is stronger, more rugged and easier to service. If all you want is a 5th gear for cruising, it's an excellent choice.

But the A-type is more sporty, IMO. Engagement is instantaneous and 2nd OD is an almost perfect split between 2nd direct & 3rd direct. I'm kind of sorry I didn't hunt around for an A-type to go in the Stag.



Jedi Trainee
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Looks like one for a Spitfire 1500; the upper holes are for the topcover/shifter. I bought a 1500 OD trans for some internal parts for a TR6 J-type I have. Never got around to the rebuild but will check the #s when I can get to the OD.

74.5 & 75 TR6


Jedi Knight
I have to agree with Jeff. I have a Volvo J type and the overdrive ratio is 27%. If the serial number stamped in the case is to be believed that unit is 25% which is what Triumph specified for their J types.


Jedi Trainee
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I just checked mine and "25 115867" is a J-type for a Spitfire 1500. A lot of J-type internals are common but you'd have to compare the part numbers. As others have said, the OD unit itself is sort of the tip of the iceberg when converting a non-OD box to OD.

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