[T3] Rear bearings ?

[Jim Adney]

On 10 Aug 2013 at 11:40, J. Jonik wrote:

> Re/  71 Std FI Sqbk
> 
>  While driving, out of the blue came a fairly loudish
> scraping-grinding noise, from a rear wheel area.  It didn't change
> when braking.   Coming home later, the noise wasn't there...but it
> returned the next day. It wasn't as loud as when it first started. 

The most likely cause would be some rust rubbing between the brake 
drum and the brake backing plate. That would tend to sound somewhat 
"tinny," however, so that may not be your problem. Just taking the 
drum off sometimes gets rid of this problem, but you should also look 
for spots that have been rubbing around the outer lip, where the 
backing plate inserts into that groove in the drum. Also, check to 
make sure the springs that hold the 2 shoes against the backing 
plates are still there; they sometimes fall off and get ground up by 
the brakes.

The next thing to suspect would be a CV joint. You have axle shafts 
there, not tubes, and those should slide back and forth without 
feeling gritty. Like Bob said, make sure the bolts haven't come 
loose. Then check the 2 rubber boots; if those are torn, the CV 
joints are even more suspect, because that lets the grease out and 
the dirt in. If you jack up that wheel, you should be able to turn 
the wheel while you watch from below, for backlash in the CV joints. 
Any backlash you feel should be minimal, and you should not be able 
to see any at all. A little backlash in the tranny is normal.

Rear wheel bearings seldom go bad, but anything's possible. Just 
getting in there is a really big job, so make sure that's the problem 
before you start. The Bentley tells yo to take the diagonal arm off 
to do this job, but I'd do it on the car. I have parts if you need 
them.  

-- 
*******************************
Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
*******************************