TR6 TR series transmission compatibility

[Ottibee]

I apologize if this is not the right protocol - 1st time asking a question. I was wondering if anyone had definitive information on transmission compatibility. In particular, does anyone know for certain if a TR4A non-overdrive transmission will fit a TR6 without any modification? (I’ve had my fill of challenges this summer and am not looking for another.). Thank you.

 

[glemon]

The bellhousing and input shaft stayed the same throughout I think. The insides changed over the years, oh you may need to mess with clutch and pressure plate as well the rear transmission mount, location changed over the years and between overdrive and non-overdrive

 

[Ottibee]

Thank you. You’ve said the magic phrase to scare me away; “mess with the clutch and pressure plate.” I already have enough problems with the clutch ...... I don’t want to add another variable. Thank you again.

 

[TR3driver]

TR4A should fit, but is not as strong as TR6. Probably work fine if you drive modestly, but I wouldn't try it if you like to drive hard (as I do).

The 4A used the same clutch as TR6, so no worries there. If you did get a TR4 (instead of 4A), the only clutch change necessary is to trim a bit off the input cover (and use the TR6 clutch components, TOB, carrier sleeve, etc).

BTW, I think your "protocol" is fine. Maybe could be just a bit more descriptive on the title line, like "TR4A trans in a TR6?" but what you have is good too. It can also help if you put your commission number in your signature; for example late TR6 uses an adapter at the rear motor mount for a non-overdrive gearbox; which might be missing if you don't have the old gearbox.

PS, Welcome to the asylum!

 

[Ottibee]

Thank you for all the info - much appreciated!