From: eldred@rrunner.jpl.nasa.gov (Dan Eldred)
Subject: Re: CV joints
Organization: Jet Propulsion Laboratory
Date: Thu, 10 Sep 1992 23:46:06 GMT

In article <1992Sep10.211130.27766@mks.com> seanw@mks.com (Sean Wilson) writes:
>Hi!
>
>I'm thinking of buying a used GTi ('88 - '90), and everywhere I look in
>this newsgroup I see these ominous words ...  CV JOINT!!!!
>
>I have a number of questions:
>
>1.  Why do VW CV joints seem to need replacing constantly?
>2.  How long do they usually last?
>3.  How much do they cost to replace?
>4.  Are there any particular model years in which the CV joints were really
>    bad?
>

1.  They don't need replacing constantly.  But all designs currently on
the market require a flexible rubber boot to keep the grease in and the
dirt out.  If this boot breaks (as it eventually will do), then dirt
gets in and grease gets out, and the CV joint will fail in pretty short
order.  You can almost bet that a broken boot is the cause of a CV joint
failure.  The fact that you frequently hear about bad CV joints reflects
the fact that many people don't monitor the condition of the boots and
just wait for a noise before anything is done (==too late).

2.  The joints themselves appear to last almost indefinitely if you
make sure to keep the boots in good condition, and clean and repack the
joints when replacing the boots.  I've got 170,000 miles on my '84 Rabbit
and 150,000 miles on my '80 Vanagon, with the original CV joints (but
not boots).  My '71 bus went about 180,000 miles on the original joints,
except for one which was replaced at 150,000 miles (it had been driven
for several thousand miles with a broken boot before I bought the car
at about 60,000 miles).   On the other hand, you can expect the boots to last
50,000 to 100,000 miles, depending on how much straight-line driving vs.
turning you do, how much smog and salt there is, and what the material
is in the boots if it's aftermarket.  I had a batch of cheap boots on my
'71 once that lasted only about 25,000 miles;  those on my '84 went to 95,000
and then tore; and two on the '80 are still original while the other two
were replaced at 100,000 miles (they tore while I was removing the tranny
to replace an oil seal--not while driving).

3.  If you do it yourself, they cost about $60 or more for the joint, and
about $10 for the boot.  If you use dealer parts, double these numbers.  And,
no, I don't know if they're better, or worth the cost.  Labor for doing it
is going to be somewhat steep--figure $150 per axle (it's easier to do 2 at
once), as the job is a pain in the butt.  I am guessing at the labor figure
since I have always done it myself.

4.  Not that I'm aware of.  VW/Audi does seem to make pretty good CV joints,
and they have been at it for longer than most companies--they were using them
on their cars at least as far back as '68.  There appear to be only a few
different joints made for all the cars--for example, my '80 Vanagon uses
the identical same CV joints as my '71 Bus did.

So my advice is:  make sure the CV joints are ok when you buy the car, and
then poke your head under the car every oil change (3000-5000 miles) and
inspect the boots.  You should also inspect the boots protecting the rack
and pinion steering at the same time.

	- Dan