TR2/3/3A Is the 4A Gearbox Top Cover the same as the TR6 Top Cover?

[karls59tr]

I accidentally knocked a TR6 top cover off the work bench and I must have dislodged one of the detent balls. I have a top cover from a 4A that I could use rather than try to repair the damaged one. Are they the same.....both are synchro in first?

 

[TR3driver]

I believe they interchange, as far as the shift fork locations go. There were a lot of variations in TR6 top covers, but mostly in where the switches were located and how the shift detents were retained.
https://trf.zeni.net/TR6bluebook/82.php

 

[glemon]

Would agree, don't think the 4A had back-up lights, so there is a switch for that you will be missing, but it should work otherwise, other variations would be overdrive switches which allow the O/D to work in certain gears but not in others, but it is not too hard to add these as needed, as far as how they work with the tranny to shift the gears pretty sure they are interchangeable if not exactly the same.

Good write up on rebuilding the top cover on the VTR website if you decide to stay with what you had.

https://vintagetriumphregister.org/maintain/TransRebuild/TRTrans02.pdf