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TR2/3/3A Putting a J type in a TR3A

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Got_All_4

Got_All_4

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I have a 1960 Tr3A and recently 1st and reverses gears blow up. I may have a line on a J type trany out of a TVR. What issues would I run into trying to install this in my 3A?
 
I've herd that the mounting flange where it mounts to the engine block is thicker so I'm concerned that there will be clutch problems?
 
No serious problems at the engine; I have a TR6 gearbox in my TR3. The extra thickness is to the rear, so no affect on the clutch. You'll just need longer bolts & studs, plus some adaptation because the clutch slave cylinder is a bit farther to the rear.

But the J-type is a major problem at the rear, as it's adapter is 4-5" longer than the A-type adapter. That puts the large part of the OD farther back, where there isn't enough room between the frame rails (and probably not under the tunnel as well). The rear mount is also completely different and would have to be fabricated from scratch.

Couldn't find a really good photo, but maybe this will give you some idea
 
Here's a somewhat comparative photo of an A-type, where maybe you can see how much farther forward the OD body is. The flange will be in the same location as the J-type above.
 
Here's a link to an article on installing a J-type overdrive in an early TR250/TR6 (and TR4A) frame from the Buckeye Triumph website.
Transmission adapter for J-type overdrive in A-type frame

I'm not sure how applicable this would be to the TR3 frame as I've never seen the rear transmission crossmember and mounts.

Scott
 
Wow ok good info. Not going to be easy. Would the drive shaft need to be shortened too if it's 5 inches longer?

Here is another scenario. I also have a 69 TR6 waiting to be restored. It has a A type overdrive in it. I may sell the car and if i do I'll pull the trany and it sounds like the A type will fit right up to the 3. Now as far as the 250 it was restored with a later tr6 frame under it. Sounds like the J type will bolt right up to it? I had to get a adapter plate to mount the 4 speed to it. Then both cars will have overdrives.
 
No, the driveshaft is OK. Note how the J-type is much shorter behind the speedo drive. They made the adapter longer to keep the overall length the same.

Your plan of A-type in the 3A, and J-type in the 250 sounds more workable to me. Personally, I think the A-type is more sporty anyway; the accumulator makes it shift much quicker than the J-type does. I'm a bit sorry I elected to put a J-type in the Stag (but of course it's not a sports car).
 
BTW, there are still some small mods needed to fit the TR6 box in the 3A. Longer studs in the back of the engine, move the holes in the rear crossmember, that sort of thing. Should be no problem, but it's not quite a drop-in operation.

First time I did it, I didn't realize that the 4-synchro box is a bit longer than the original 3-synchro, and just forced it in. For some reason, my motor mounts didn't last very long ...
 
The short story is that on a tr3 or early 4 the J type is big trouble for the exhaust routing.You will have to run your pipes under the center of the car.This will give you next to no clearance at all.The sixes ride higher..and have 2 smallish pipes.
I would just go to the Toyota 5spd and have done.Eagle Gate has a very nice kit and the trans is cheap and parts are too.
MD(mad dog)
 
MDCanaday said:
I would just go to the Toyota 5spd and have done.Eagle Gate has a very nice kit and the trans is cheap and parts are too.
Click to expand...
Yeah, but then you are driving a 5 speed manual Toyota, instead of a 7 speed semi-automatic Triumph!

And no one will ever say "What IS that switch you keep playing with !?"
grin.gif
 
You said it Randal"when you are driving" Having lived with a J type in my 6 and an A type in my 4 and fixing the blasted things for several friends,I must say that dropping in a supra tranny is a breath of fresh air.Under the bench is a great place for an aging gear box to rest up for the next 50 years!!
MD(mad dog)
 
I'm with Randall on this one. Wire wheels and overdrive are part of the character of a British sports car for me.

Scott
 
Well, when the original A-type in TS39781LO finally got 'tired' after over 30 years of service; I dropped in an A-type from a 56 that was found sinking into a cornfield (and bought for $500). That one was still working (although poorly) when I finally got enough money scraped together to rebuild one properly. The rebuilt one is still going strong today in spite of the car having been totalled.

I'll happily compare that to ANYTHING Toyota built before 1960 ... and if I really want to drive a modern Toyota, I can always borrow the wife's Camry. It just turned 20, and has already left her stranded in the middle of I-10 because it's tranny literally locked up. Months after getting a replacement tranny, it suddenly started pissing oil far worse than any Triumph. It will be in the bone yard soon.
 
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