[Top] [All Lists]

Re: U-joints, 78 suburban

To: Matt Wehland <>
Subject: Re: U-joints, 78 suburban
From: Dave & M <>
Date: Wed, 25 May 2005 17:13:08 -0600
Hi Matt,

Since the problem just appeared, I'd guess it was related to the U
joints. There may be something preventing the cups from fully seating.
The fit of these parts must be nearly perfect.

I doubt of overtightening would cause the problem.

I once got a U joint together with on of the needles out of place
between the trunion & the end cap. The snap rings went back in & I
thought all was well. But the joint was forced slightly off center.Made
a terrible vibration & noise. Pulled it apart & put the needle back
where it belonged, & all was well.

Dave Russell

Matt Wehland wrote:
 > Hello, I just replaced the ujoints in my 78 suburban (front & rear, 1
 >  piece shaft). I now have a  noise, sounds like grinding metal from
 > the rear. It is most pronounced from 10-25mph, above 25 the frequency
 >  becomes higher and the rest of the truck makes so much noise that I
 > don't notice it. I checked the shop manual (after reinstalling the
 > shaft) and noticed that it calls for around 20ft-lbs on the rear
 > strap bolts (4 bolts that hold the joint to the rear axle).  I had
 > torqued the heck out of them.  So I loosened them up, lock-tited them
 >  and retourqued them to a guesstimated 20-25 ft-lbs (much less than I
 >  had them before). I also had one of the rear bearing caps fly off of
 >  the shaft and roller bearings go all over while installing the
 > joint, I cleaned them up real good and got them all back in place.
 > Also the pinion seal has been leaking for some time now, I haven't
 > even looked at it yet. The truck sat for 4-6 weeks, only driven once
 > before I got around to replacing the u-joints.
 > What is the best guess on what is making the noise? Did I screw up
 > the u-joint by over-torqueing? Dirt in the bearings from when I
 > replaced everything? Something with the pinion bearing that became
 > worse after replacing the u-joints? Bad u-joint from the factory? It
 > was real tight when moving by hand, but it is brand new so?
 > I have no problem replacing the u-joint again if that really is the
 > problems, but I'd hate to do it and then find out it was something
 > else stupid.
 > Thanks, Matt

<Prev in Thread] Current Thread [Next in Thread>