TR2/3/3A turn a tr3 non-full syncro transmission into a full syncro

[sp53]

I remember hearing years ago that I could turn a tr3 non-full syncro transmission into a full syncro just by changing the main shaft and probably getting a different first gear, I do not know. Anyways there is local guy selling some tr6 main-shafts on Craigslist, and I was curious if anyone had heard similar stuff and if a tr6 main shaft would fit inside a tr3 case.

Steve

 

[karls59tr]

I put a TR6 transmission in my TR3 years ago. The only modification I had to make was to relocate the bolt holes on the rear mounting bracket....moved them back about 3/4".

 

[charleyf]

If you look at the exterior of the two diffrent trannys you will see a marked difference. Especially where the the first and reverse gears are located.
My answer is it is not possible to make a TR3 adapt to having a synchro from 2nd to1st.
Charley

 

[CJD]

Unfortunately, "no". The case is different. Some of the gears are interchangeable, but not enough to add the synchro. The difference in the case is the "bump" required for the reverse gear in the full synchro box.