[65 Lamnas]

Originally Posted by chiphead

How loose does the TH400 extension housing bushing/yoke fitment have to get to cause driveline vibration? What is the clearance between the yoke and the bushing supposed to be?

I've had a driveline vibration at 65-75 MPH with both the original driveshaft and the aftermarket shaft that's in there now. The yoke has a a few thousandths of slop if I wiggle it up and down in the extension housing. I replaced the seal when I swapped driveshafts, but can't remember if I did the bushing.

I pulled the shaft last night in order to drop the trans. The new 1350 yoke has the coating worn off on one side, after 2K miles. It's def been wobbling as it ran. Can I just pound in a new bushing or what else do I need to check?
With yoke removed, I can wiggle trans output shaft roughly .040" back and forth. Is that normal?

I don’t know how much clearance or wear it takes to cause a vibration. The wear limit on that bushing is .008”

Measure the OD of the yoke with a mic, and the ID of the old bushing too. Put in a new bushing and remeasure.