Re: 37 Senior trans problem

Posted by Tim Cole On 2015/7/23 14:55:14

Hi Ross:

If you look in the 33-36 parts book (same trans) you can get an idea of what is happening.

Once the sychro yoke moves forward and the dog clutch engages the yolk pops back; the blocker ring should then be free from the hub. I suppose if there is not enough end play a lock up situation could happen. You should be able to visually establish end play of the blocker ring.

If you look in the manual there is a procedure for setting the shim size via measuring the yoke travel. It's around 9/64 to 10/64+ inches.

If there is end play of the blocker ring then the intermediate speed bearing has broken apart and locked up.
This would allow two gears at once without any interlock.

So this case is a teardown. You will need to buy shim stock to cut you own shims. Also, the procedure in the manual assumes worn parts are replaced, so if the blocker rings and gears are worn the process becomes very judgmental and artful. I used to get into long arguments with belligerents who didn't believe that great care and judgment is required to properly set up one of those old transmissions. Which is one reason I prefer to work with the engineers here in Detroit rather than old car maniacs.

I've heard someone made up new blocker rings and that may be a help.

Best wishes, and remember that is a hand built transmission.