PDA

View Full Version : Bad driveshaft vibration - May I?



blankenship
06-13-2022, 12:27 PM
My '95 Alltrac has a really bad driveshaft vibration when accelerating so I'm thinking it might be out-of-balance -
Also thinking the U-joints are shot because there's a little *hesitation then catch* clunk half the time when accelerator pedal is depressed at speed.

I recently replaced a *destroyed* carrier bearing hoping that would fix the problem, but no luck.
For what it's worth, the 'SADS' couplers are also new.

I've been sinking a lot of money into the van, and can't quite bring myself to spend the $1000+ to put into driveshaft replacements right now.
I'm wondering:

How to identify whether it's the FWD or RWD shaft that's causing the issue?
Can I disconnect the problem shaft to possibly eliminate the vibration issue? (And just have a temporary 2WD Previa?)
If I'm correct on diagnosis...that these are symptoms of viscous coupler problem?

Help much appreciated!

Previologist
06-14-2022, 10:05 AM
you should be able to grab the shaft near the joint and feel for play in it in order to determine which u-joint is at fault. You cant drive the 95 far without the rear shaft, the van will lose all drive power and you'll need a tow. Earlier ones (at least the 91) weren't as "smart", so you could drive without it but you absolutely needed the emergency brake when parked because "Park" wouldn't hold.