Check Your CV Bolts Boys!!

Wrecked944 · 11-24-2005, 07:10 PM

YIKES! I replaced my CV joints about a month ago and then yesterday my car began making that familiar "clunk clunk" sound again. I coud barely believe what I was hearing because the CV's were brand new. But then fellow Pelican Chrisbennet suggested I check to see if the CV BOLTS had backed themselves out and VOILA! Chris was correct. The bolts on the outer CV had backed themselves all the way out and one had even "gone on holiday" and was missing from the car!

So I re-torqued them all and the clunking is gone. So here is a warning to all: Check your CV bolts!!

Dantilla · 11-24-2005, 07:33 PM

I haven't checked mine for a while. I will soon!

Thanx for the reminder.

Craig 930 RS · 11-24-2005, 07:34 PM

Happened here..check em!

walt · walt's Garage

Did you use schnoor washers? I used fresh bolts with these locking washers and, so far, so good.

Zeke · 11-24-2005, 10:24 PM

CV bolts need to be retorqued after 100 miles. That is with new washers, clean thread bores and Loctite. W/o those factors done correctly, you may not get 100 miles. Seems like the 2nd torquing will keep them tight for some time, but it never hurts to check at oil change intervals.

emcdan · 11-25-2005, 11:24 AM

I noticed that 3 on my driver side had backed out recently. I locited and re-torqued but they have loosened again. Does anyone else have some good solutions?

RoninLB · 11-25-2005, 11:40 AM

saftey wire may be unnecessary for most guys.

randywebb · 11-25-2005, 12:49 PM

Soln is to use new Schnorr washers, and to clean the bolt threads and female threads with brake cleaner - should be no grease in there. Go back and retorque after 100 miles as per above.

Some use Loctite - I don't and never have problems.

GIBSON · GIBSON's Garage

Randy's technique has worked well for me. In the 70's I was driving on the 10 freeway at the 405 interchange when one of the CV joints parted company with the trans. That is not a great place to loose drive. No breakdown lane. Since then I've checked them every few months.
It's really easy for the CV bolt to be covered in grease on the early non-sealed CV joints and back right out. Clean bolts, new washers and check torque at 100 miles.

cashflyer · 11-25-2005, 01:29 PM

Quote:

Originally posted by RoninLB
saftey wire ...

That's EXACTLY what I was going to suggest!

safe · safe's Garage

Quote:

Originally posted by randywebb
Soln is to use new Schnorr washers,

What is a Schnorr?
Picture?

island911 · 07:42 AM

saftey wire ... schnoor washers . .. loctite . ..

you guys . . NONE of that is enough.

Every CV bolt should have a calibrated torque wrench engaged always. -- and never drive a car with CV's!

seriously...

Quote:

Originally posted by GIBSON
.. .
It's really easy for the CV bolt to be covered in grease on the early non-sealed CV joints and back right out. Clean bolts, new washers and check torque at 100 miles.

My thoughts exactly. (except for new washers)

Dry bolt-head & contact surfaces will provide plenty of torque lock to keep the bolt in place. (edit: assuming/implied proper torque)

randywebb · 11-25-2005, 02:28 PM

Magnus - you need to do some searches - try to put recale in the search box - he did a nice how to do it on this

those are special serrated lock washers

also get a Bentley manual and find the VW manual pages someone posted when you search

you will then be well prepared to do it right.

efhughes3 · efhughes3's Garage

Very timely post, as I'll be bolting my outers up tomorrow as part of the re-assembly of my rear suspension. Thanks!

rcecale · rcecale's Garage

Lots of great info on this topic from the likes of Randy Webb and Grady Clay here

Randy

JasonAndreas · 10:21 PM

Janus,
The 964 CV joints are torqued to 31 ft.lbs if you have the M8 panhead screws and 59 ft.lbs if they are M10. Also, the torque specification is WET (just the threads) not dry and the recommended lube is Optimoly HT (copper grease). The flange covers that tie two bolts together should be dry.

ktr6 · 11-26-2005, 11:17 PM

I check mine every other weekend or so since mine backed out one day. It takes all of 3 minutes with an allen key. Don't even have to take the wheel off. My drivers side bolts tend to loosen up occasionally.

safe · safe's Garage

Quote:

Originally posted by ktr6
I check mine every other weekend or so since mine backed out one day. It takes all of 3 minutes with an allen key. Don't even have to take the wheel off. My drivers side bolts tend to loosen up occasionally.

If they loosen up something must be fundamentally wrong, right?
I mean they are supposed to be installed and forgotten for 100000 miles, as on all other cars.

efhughes3 · efhughes3's Garage

Now I'm thinking about this. The factory torque specs are only about 30lft-lbs according to Bentley (8mm bolts). If this is such a common issue, doesn't that seem a little low?

Gunter · Gunter's Garage

No need to apply the Grand-Unification-Theory here.
With gaskets, the bolts may have a tendency to back out because the gaskets get squished over time.
I don't use gaskets. If the mating surfaces between CV-joint, and flange are clean and true, gaskets are not necessary IMHO.
New Schnorr washers, lube the threads, BUT NO LUBE ON THE HEADS/WASHERS for wet-torque of 30 ft-lb on the 8 mm bolts.
The Allen bolts are high tensil-strength (12.9) and can take a little more.
If no halfmoon-shaped plates are used, check the bolt-length; sometimes the bolts may stick out a little and need to be ground off one or two threads.
Replace the bolts if they are really old with new ones. When the inner hex is nearly rounded off, it's time to get new ones.

Seems to work.