'35 t-plane transmission

tigermoth

hello, finally got the '35 back on the road after engine overhaul. the trans slips out of third gear. sliders are adjusted correctly, shifter is locked in third, but unless i hold a little up pressure while in third it will pop out of gear. (the sliders are still holding the shifter in the third gear position with the transmission in neutral) i am going to continue to drive it through the summer, but what parts should i be on the look out for before i pull it this fall? what parts typically wear? shifting fork? thank you. sincerely, tom

Unknown

Tom, I am doing one of these transmissions now. Only difference is that it is popping out of 2nd. What I've found was the shift rail was worn badly where the detent ball goes. I was able to find a new clutch dog piece , thats the piece that goes inside the 2nd gear and either engages the high gear synchros or the 2nd gear synchro. Your input shaft that has the main drive gear on it also has synchros on it. They might be worn out also the clutch dog might be worn also. I would try to find everything related to making the tranny stay in third gear. The shift rail could be worn also like in the one that I am working on. Hudson changed a lot of internal parts on these transmissions so watch your part#'s.

Geoff

It could be that the mainshaft is too far forward, but if the end play is correct, then you will have to install a thicker gasket in the rear housing, and remove shims from the front bearing cap to bring the mainshaft back. Check the mesh of the 2nd gear teeth and sleeve, they should be in full contact, but not protruding out the back of the gear. Also check the end play of the 2nd gear assembly. The thrust washers may be in need of replacing. However the shift sleeve dogs could be worn tapered, or the mainshaft dogs, or both. If so ,you can grind them straight with a small stone. However if you are not familiar with these boxes, don't mess with them until you familiarise yourself with the details. Good luck,

Geoff.

tigermoth

thanks geoff and hudson 1...in reading your notes i realize i said popping out of 3rd...i meant to say 2nd gear...always proof read. thanks guys. sincerely, tom

Geoff

Ah, that puts a different light on things, as 2nd gear is the one it usually pops out of. This is usually caused by worn drive dogs on the second gear and selector sleeve, but can be caused by incorrect adjustment of the mainshaft by removing shims to adjust end play. There is a matter of interpretation here, as Motors Manual says to adjust end play by removing shims from the front bearing cap, whereas the Hudson workshop says to adjust end play when assembling with new parts by adding shims. You need to check the mesh of the 2nd gear drive teeth when it is engaged, and they should be in full depth mesh. If the mainshaft is too far rearward, you will have to bring the whole assembly forward by adding shim washers between the rear bearing and the topshaft 1st gear, and adding shims to the front bearing cap to adjust end play to around .008". Of course you also need to check that the detent shafts are not worn, and the springs in good condition. The locks on the side of the gearbox should hold it in gear, but these are primarily to ensure the clutch is engaged before shifting gear, rather than holding the gear engaged. If the drive teeth are worn, nothing will hold it in gear. Good luck,

Geoff.