Pinion Angle

[SnoDrtRider]

I did a search and came up blank...

I have a rumble (slight but annoying) at 50-55 MPH in my 95 AWD. I don't know if it was there before the lift or not. I lifted the van 3" last year with the normal 2" sub-frame spacers/1" torsion lift and S-10 rear springs.
Since in actuality I only changed the relationship between the transfer case and rear axle 1" it does not seem to me that the pinion angle would make a big difference... is my thinking correct on this or should I shim the diff 1* to allow the drive shaft and pinion to run on a closer plane in relation to each other?

Right now the pinion is pretty much parallel to the ground by eyeballing it.

[LiftedAWDAstro]

Using an angle finder is the easiest way. That way you know if you need to adjust the angle at all. I posted it on here before with pics...I'll look for a thread....

Here's one.

I also will recommend changing out the transfer case output bushing and seal since they are cheap and I chased the same vibration for over a year.

[SnoDrtRider]

Thanks! It did not show up on a search for Pinion Angle the drivelines.com link is a great help!

[Rebel]

If I remember correctly, the pinion should be angled up the same degree your tranny is angled down.

[doyoulikeithere]

Use an angle finder to see if the 2 u-joints are parallel, or how far out they are.
If Its off parallel too much it oscillates, wears parts.
Its possible that you changed the angle with the new leafs.
I gotta do the same one o these days.

That being said, these old 10 bolts are getting pretty old and tend to wear out I'm noticing after 4 or 5 vans now.