Drive yoke hitting floor pan.

[SS_Sean]

I had the Buick down for some service work and the tech calls me and says my driveshaft yoke is hitting my flloor pan right at the tail housing of the tranny. He said he stood on the brakes and he could hear it hitting the floor, whack, whack, whack!

A couple weeks ago I went in and replaced the crossmember rubbers at each frame rail, I installed a HRParts trans mount, and everything looked okay. I also have a brand new driveshaft with 1350 u-joints. Now, I have a driveshaft safety loop installed, so I can't imagine the yoke could hit the floor pan at all. Can anyone fathom how the rear of the tranny could move upwards enough that the yoke is hitting either the floor or the top of the drive shaft loop? It shouldn't be moving at all, period.

 

[Squid4life]

I would crawl underneath and verify that it is hitting and where. Not really sure how hitting the brakes would make it move all that much...

 

[Nick Micale]

It can hit the loop, especially with 1350 u-joints.

It will sound like it is hitting the floor pan. :smile:

We have had to modify or space down many hoops.

Guess you may need to check your motor mounts?

 

[SS_Sean]

Thanks. The more I think about it the more I'm convinced it's the u-joints hitting the bottom of the drive shaft safety loop. If you get on the binders the distance between the body and rear diff opens up, which moves the u-joint down towards the bottom of the loop. I can certainly space the loop down a little or cut it and open it up a little bigger.

Thanks again....