Late Model Transmission Problems

[SasquatchSanta]

I recently installed a NOS late model transmission in my M37. Not long after installation, I experienced a problem while attempting to downshift on a steep hill on a rural road.

The first time the problem surfaced I noticed a small amount of smoke coming out of the top of the transmission shifter tower after down-shifting to second gear. When I downshifted I noticed what I would term as extreme drag coming from the transmission. The problem didn't last long and after experiencing the drag and noticing the smoke coming I was able to put the transmission in and out of gear and the problem went away.

Last night the problem happened again. Once again, after downshifting on a steep hill, smoke came out of the tower after downshifting and the engine pulled down from what appeared to be drag coming from the transmission. This time, I had trouble getting the shifting mechinism working. After a short time of moving the shifter through the gears (while standing still) I was able to get rid of the drag and smoke BUT it wouldn't go into 4th gear.

I drove home in 3rd gear. After arriving home I checked the 80/90 fluid lever. The transmission nor the shifter tower wasn't hot and there wasn't any roll-over noise.

Given that smoke came out of the upper part of the tower as the drag was experienced it appears the problem is somehow centered in the tower.

As mentioned before, the transmission is a NOS late model unit.

Anyone fot any insight?

 

[m376x6]

Pull the floor pan and remove the shift tower with the transmission in neutral. Is this a US version style transmission. If it is, it is only synchro'd in 3rd and 4th gears. Sometimes the shift towers get bolted down with out having the forks over the tangs correctly. If you keep trying to work it loose you'll crash the entire transmission.

Regards,
M376X6

 

[SasquatchSanta]

Update

Soldier Number-One and I pulled the transmissions and opened it up.

Someone either failed to install the spacer (used to replace the spedo drive gear in civilian models) between the rear bearing and companion flange OR someone removed it after the transmission was assembled. Without the spacer the main drive gears were able to move back and forth. It's a wonder the transmission didn't blow up. I was able to find a spacer and set of syncros from Bob Stahl at Veterans Vehicles.

Sometimes you can't even trust NOS