I have a 92 d350 dually with getrag and it has a vibration and leaking oil. The main shaft has a good bit out play up and down. I took transmission out and it seems like it doesn't have enough shims? Bearings feel real good. It has 95,000 miles on it. What thickness of shims should it have? Should it have any play? This is my first time working on one.

 

Here's the getrag rebuild manual http://www.dieselhub.com/PDF/Getrag-G360-manual.pdf

On page 21-71 it talks about the shims. You want 0.006 - 0.008" of preload with your shims. You'll need a depth micrometer to do it properly.

 

Is this a common problem that need add shims time to time? Or do I have something else wrong?

 

Once the end play is set, it should stay that way. If the end play increases you have bigger problem internally. My guess is that the bearing(s) are going bad. Even though they "feel" fine, doesn't mean they are.

I would tear it down for a full rebuild...since you already have to tear it partly apart to try and band aid fix the end play. New bearings, and syncros at a minimum.

 

Where do you recommend getting rebuild kit from?

 

I got mine from zumbrota bearing and gear. Best price at the time when I did mine.

Make sure to get the bearing preload exact or there's a good chance you'll have issues later on.