I installed a new center section in my car and now have a vibration on decel. It was new from moser. When I was installing it I measured and squared the rear end in the car. I moved one side back 3/16" to get it square. The driveshaft seems to have quite a bit of play up and down in the transmission. When DS is installed it is 1 3/8" from fully engaged in the transmission. I've always been told push the yolk clear in and pull out 1" is correct. I assumed 3/16" wouldn't cause an issue but not sure. When I squared it I obviously pulled the DS out slightly. The rear doesn't make any noise and seems smooth when I jack it up and run it through the gears. Thoughts from people with more experience than me? The tail shaft has some play but I'm thinking that is normal. It is a roller tail shaft with the hardened roller yolk.

This message has been edited. Last edited by: inferno camaro,

When i had my door cars (4 Link). It was 3/4 to 1"
Out with the suspension loaded. No free hang. Stands under the axle.

The perfect pullout drag racing is 1" to 1.250".

1.187 pullout is not your vibration

My bad its actually 1 3/8 not 3/16

quote:

Originally posted by inferno camaro:
My bad its actually 1 3/8 not 3/16

Ok, and?

Its 1 3/8" out of trans not 1 3/16". Don't think that would affect anything? It is all the way through the roller bearing.

quote:

Originally posted by inferno camaro:
Its 1 3/8" out of trans not 1 3/16". Don't think that would affect anything? It is all the way through the roller bearing.

You wanna know if it's the new chunk is growling on decel, probably is, BUT there's only one way to find out for sure.

What brand gear was used?

Move the entire assembly forward .125", to achieve ideal drive shaft pullout. At least you'll know it's straight.

I think Moser uses US gear.

quote:

Originally posted by inferno camaro:
I think Moser uses US gear.

Get ya some compound, look at the pattern. It'll be the first step to doing them for yourself.

Fix your driveshaft pullout first of course, see what that does.

I just did this one up, quiet as a mouse.

If you have two chunks now, What I did is setup a third complete pinion support and pinion gear for a third option.

Makes for a easy third option gear change.

I slid the rear forward 3/8" and vibration is gone.

Good deal!

Egg center: Yolk
Trans/rear: Yoke

Depth, Should be able to pull the driveshaft out with all suspension components loaded. The u-joint should clear the rear or the front yoke (if it is removable) without jacking the car to let the rear hang.
A chassis car with a 4 link will not have as much need for expansion as a ladder bar car. If 3/4 inch will allow the shaft to come out then that is all you need, If it is an inch then that is what you need. If you moved the yoke 3/8 back into the trans and the vibration went away you have some underlying issue, as 3/8 is not enough to make a drastic change, unless the yoke is not machined correctly.

This message has been edited. Last edited by: Bad News,

I called Mark Williams and the told me it should be pulled out of the trans .75-1" Mine was 1 3/8" out and they told me that would cause a vibration.
The yolk was was just barely through the roller bearing before so maybe that was part of the issue.

3/4 to 1" has been the standard for 100 years. Roller or bushing. Glad the shake is gone.
Smooth sailing.

quote:

Originally posted by TD3550:
3/4 to 1" has been the standard for 100 years. Roller or bushing. Glad the shake is gone.
Smooth sailing.

Yep was my bad, it use to be 1" but the rear was crooked. When I squared it I pushed it back to 1 3/8 and didn't figure it would matter (WRONG)