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Wed Jul 01, 2015 12:25 pm

after our last camping trip, I noticed a bit of a clunk when reversing into our spot. Today I got under the van and low and behold 18 of the 24 bolts were not fully torqued down to 33 ft.lbs. is this common for them to slowly backout? Should I add this to my yearly maintenance check? Is loctite used on these bolts to prevent this?

Thanks

Wed Jul 01, 2015 12:38 pm

Yes, check them yearly or more often if this is an issue. I would not use locktite for risk of not being able to remove when doing maintenance, maybe blue if ever... I torque mine down in two stages, 20 ft.lbs then 36 ft.lbs then check after 100 miles and they stay tight (so far), for the last 400,000 miles I have not had one loosen, but I know that plenty of folks do have that issue so mine may be the exception. YMMV.

Wed Jul 01, 2015 12:46 pm

when I first did my CV's (first time) I used blue Loctite. It held fine but was a minor pain to clean up. Just re-did CV's. Did not use Loctite. Still holding fine. I was VERY careful to evenly torque the fasteners in diagonal pattern. (like final torque on vehicle wheel)

Check that each bolt has the correct serrated washer between bolt head and metal plate thing.

Neil.

Wed Jul 01, 2015 1:17 pm

Vanagon Nut wrote: when I first did my CV's (first time) I used blue Loctite. It held fine but was a minor pain to clean up. Just re-did CV's. Did not use Loctite. Still holding fine. I was VERY careful to evenly torque the fasteners in diagonal pattern. (like final torque on vehicle wheel)

Check that each bolt has the correct serrated washer between bolt head and metal plate thing.

Neil.

Hmmm...i did not see any serated washers on any of them... The metal clips were in place, but no washers....looks like a trip to the hardware store is in order.

Wed Jul 01, 2015 1:22 pm

They are one time use... Big part of why they come loose. Get a fresh set of bolts.

Wed Jul 01, 2015 1:39 pm

http://schnorr.com/products/safety-washers.html

Wed Jul 01, 2015 1:54 pm

kustomizingkid wrote: They are one time use... Big part of why they come loose. Get a fresh set of bolts.

So the bolts need to be replaced each time?

Had not read or heard of this before...

Wed Jul 01, 2015 2:02 pm

that might be because it is completely incorrect - the "bolts" (cap screws) can be reused for decades - carefully inspect the threads and the wrenching fixtures on them

they are NOT one time use only

BUT!!! the Schnorr washers ARE one time use - many threads here on this so find them and read carefully the part about cleanliness of threads

and NO do not use something else form a local hardware store - a trip to the hardware store is not in order

I would also add the moon plates as used on Porsche 911 CV joints (up until 1980s cost cutting resulted in their deletion)

Blue Loctite will not kill you but is not needed if you do it right

so it wrong and you can see what a flailing steel rod can do to tranny & engine when it is swung around at the same high speeds as a mower blade

Wed Jul 01, 2015 2:05 pm

Ah, thanks for the clarification. Bad to not use the washers? I've done it both ways and haven't had them loosen on me without them...

Wed Jul 01, 2015 2:11 pm

T3 Pilot wrote: http://schnorr.com/products/safety-washers.html

nice link.

anyone have a source for these at a good price? thinking I'd like to order like a box or something.

hate paying $3 ($0.25/ea x 12 Go Westy plush shipping if not w/another order - I wish I could just drill a hole in a quarter) to $13 ($0.95/eax12 local VW service shop) each time I want to remove a CV axle.

Wed Jul 01, 2015 2:12 pm

If the bolts are too loose they will fatigue and thus are more apt to break down the road even if later tightened to spec. If the bolt has been properly torqued and stayed that way then I don't have qualms about reusing them.

The Bay Window guys fight themselves over these bolts as the early torque spec for them is a measly 24 ft*lbs, and thus the bolts tend to come loose and their steel fatigues. The Bay guys do all kinds of stuff to try and fix their issue, cleaning the threads of all grease, using Loctite, wiring the bolts heads, etc, but seem morbidly afraid to use VW updated torque spec of 33 ft*lbs.

Wed Jul 01, 2015 2:38 pm

I wasn't aware that those washers weren't re-usable. That said, I've reused them with Loctite on threads. Not saying that is correct however.

It also can't hurt to make sure the CV and flange faces are totally clean and that threaded holes are clean and free of CV grease.

Neil.

Wed Jul 01, 2015 3:07 pm

I use these myself.

http://www.mcmaster.com/mv1434659457/#93501A030

Wed Jul 01, 2015 4:41 pm

I'm going to out myself on this one. I've always reused those washers and the bolts ( as long as the allen head is not worn) and have never cleaned the grease away fromthe CV holes. Knock on wood I've not had any issues. Just set myself up probably. 😁

Wed Jul 01, 2015 5:20 pm

Wildthings wrote: If the bolts are too loose they will fatigue and thus are more apt to break down the road even if later tightened to spec. If the bolt has been properly torqued and stayed that way then I don't have qualms about reusing them.

The Bay Window guys fight themselves over these bolts as the early torque spec for them is a measly 24 ft*lbs, and thus the bolts tend to come loose and their steel fatigues. The Bay guys do all kinds of stuff to try and fix their issue, cleaning the threads of all grease, using Loctite, wiring the bolts heads, etc, but seem morbidly afraid to use VW updated torque spec of 33 ft*lbs.

Good point - if the bolt loosens it will be loaded in SHEAR with the full torque of the engine & trans.

The job of the bolts is NOT to transfer torque as is usually assumed. The powertrain torque is transmitted by the flange surfaces. The bolts keep those surfaces tightly pressed together.

So to amend my earlier post: The bolts are reusable (after inspection) when properly installed and used. IF you (or a PO or a "perfessionale" mechanic) eff up, then replace them all. I also like to replace anything older than 50 years on a vehicle...

Wed Jul 01, 2015 5:22 pm

Randy in Maine wrote: I use these myself.

http://www.mcmaster.com/mv1434659457/#93501A030

I know that lots of racers use the Belleville washers. The cost of the Schnorr washers is not high when you realize how infrequently you need to remove the CV axles (you guys are dropping the entire powertrain for a rebuild after each weekly vanagon race are you?)

Wed Jul 01, 2015 5:31 pm

Merian wrote: Wildthings wrote: If the bolts are too loose they will fatigue and thus are more apt to break down the road even if later tightened to spec. If the bolt has been properly torqued and stayed that way then I don't have qualms about reusing them.

The Bay Window guys fight themselves over these bolts as the early torque spec for them is a measly 24 ft*lbs, and thus the bolts tend to come loose and their steel fatigues. The Bay guys do all kinds of stuff to try and fix their issue, cleaning the threads of all grease, using Loctite, wiring the bolts heads, etc, but seem morbidly afraid to use VW updated torque spec of 33 ft*lbs.

Good point - if the bolt loosens it will be loaded in SHEAR with the full torque of the engine & trans.

It is not only the shear load, but any oscillating load that causes fatigue in a poorly torqued fastener. If when you go to remove a CV and you find that the threads of the bolts are being damaged as you remove them, then you know the CV joint has shifted in relation to the flange.

Wed Jul 01, 2015 5:45 pm

As I mentioned earlier, I did not notice washers being in place...but I didn't look either. As would be expected, there was grease and grime. Do theses washers extend beyond the edges of the bolts, or do they sit flush with the edges which would make them hard to spot under the gunk?

I guess I am feeling paranoid, but would rather not replace them if I don't need to. I guess I will go back out and inext more closely tomorrow.... Sigh....

Wed Jul 01, 2015 5:47 pm

VWinVT wrote: As I mentioned earlier, I did not notice washers being in place...but I didn't look either. As would be expected, there was grease and grime. Do theses washers extend beyond the edges of the bolts, or do they sit flush with the edges which would make them hard to spot under the gunk?

I guess I am feeling paranoid, but would rather not replace them if I don't need to. I guess I will go back out and inext more closely tomorrow.... Sigh....

They are very thin and barely larger in diameter than the bolt head.

Wed Jul 01, 2015 5:50 pm

Wildthings wrote: VWinVT wrote: As I mentioned earlier, I did not notice washers being in place...but I didn't look either. As would be expected, there was grease and grime. Do theses washers extend beyond the edges of the bolts, or do they sit flush with the edges which would make them hard to spot under the gunk?

I guess I am feeling paranoid, but would rather not replace them if I don't need to. I guess I will go back out and inext more closely tomorrow.... Sigh....

They are very thin and barely larger in diameter than the bolt head.

Aha! All is not lost! :D I will still go and check tomorrow.