• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

TR6 Moving TR6 gearbox to TR4a - any issues?

Share this page

T

tdskip

Yoda
Country flag
Offline
Hi guys - one thing that did go very right yesterday on the trip to the shop is that it confirmed that the gearbox in the '74 TR6 is in good shape. No slipping, nice tight shifts.

My plan is to take this transmission out and put in the factory O/D J-type into this car, and then use this transmission in the TR4a. Any issues with moving a stock 4 speed from a 1974 TR6 to a 1965 TR4a solid axle?

Thanks!
 
I recently helped install a TR6 A Type OD transmission into a TR3a and as far as bolting the transmission to the engine there were really no issues. You will need to get some new bolts because the later trans has a thicker bell housing flange. The locating dowels appear to be too short but they will work. You should find that there are a couple of extra holes on the bell housing that will not get used on the tractor engine. Everything else should be the same.
 
No experience here... But information I believe I've heard somewhere along the journey indicates that the J-type gear box rear mount may be different. Check that out before you climb under the car to bolt it in...
 
No issues. I fitted a TR6 gear box in my 3A and I don't think I even used different bolts.
 
Check the 3 studs at the top of the engine block, against the thickness of the gearbox flange at that point. If they are long enough for a nut & lockwasher, you should be fine. On my TR3A with a later TR6 box, I had to use longer studs.

Also had to fiddle with the support rod for the clutch slave, and trim a bit off the pushrod, but that's no big deal either.
 
Back
Top