Slipping out of 3 rd on compression

[SSsssteamer]

Originally Posted by J Franklin

I had rebuilt a transmission with new gears that did the same. I had to find another mainshaft that fit better with the sliding gears. This is covered in the mechanics bulletins Dec. 1928 Pg. 303.

That was my fix too, another main shaft and gears. In my case the input shaft and main shaft did not have enough end play and they were binding end wise front to rear. The needle bearing cage that was provided in the transmission rebuild kit was too long for the input main shaft and it pressed the input shaft forward a bit which didn't help with the engagement of third gear. That plus the 3rd gear shifting fork lacked 1/8" of being in full engagement going with the third gear detent position. The pilot bearing was still fine, but I will buy a new one tomorrow just to be on the safe side. I found an almost new transmission on my shelf that had a broken case. I used the main shaft, the 2nd and third gear slider, and the needle bearings for the main shaft out of the found transmission. To be safe, I should have probably swapped all the innards out into my transmission case. An interesting observation was that Ford's 2nd and 3rd gear slider will not fit onto Mac's main shaft but Mac's 2nd and 3rd gear slider will easily fit Ford's main shaft. Reminds me of the Chinese parts that we buy that don't fit properly. Thank you all for your help.