CV Joint Failure Carnage

[Tippy]

Hoy crap!

I can't believe this has happened to so many people.

Mine have always been tight.....maybe because I always put the "oil field torque" on them.....

[RWebb]

Originally Posted by Superman

Yes, the half-moon plates are factory. So are Schnorr washers. That's probably sufficient, but safety wire is a nice guarantee against this. We see this often. But rarely on a joint that was properly assembled and torqued using new parts. Including the Schnor washers.

and that lack of proper assembly is why we see this happen "so frequently"

the metal faces will retain the grease only if they are are nice and flat - which they should be

BTW - safety wire will not maintain tension on the bolts nor will it keep the faces of the CV joint on the mating part - it only prevents the bolt form being backed out all the way

the bolt will be snapped in half even when safety wired

so, I don't see any reason for safety wire...

[RJ911SC]

Ok Stupid question time,
Would Lock Tite world or help?

[Tippy]

As long as they are torqued to specs.

Removing them after Loctite will have you cussin'

[schumicat]

I have the same year, and I have seen contradictory info on this board. Some say the 82 did NOT have the schnorr washers and plates from the factory (the parts diagrams I have seen support this) and some swear they did.

Originally Posted by ohecht

Are the "half-moon" things part of the 82SC setup? I never had any on my car and the catalog does not list them, but I don't want to leave out a critical part.

My damage could have been a lot worse. The parking and regular brake cables were spared, but the heater box cable got a little tweaked. The only throttle linkage piece that is trashed is the one from the bell crank to the engine, and the bell crank pivot itself looks salvageable, even thought it was wrapped around the CV by the linkage. It is barely bent at all. It might take a week to get the pivot pin from pelican, though, which will cause a lot of down time.

Olivier

[RJ911SC]

Tippy
been doing alot of cussin on this fix, any idea what the tourqe specs are?
thanks
Rob

[KTL]

The washers are good insurance, regardless of whether they are factory spec for whatever year you have, or not. The key is to make sure the contact surface between the screw head and moon plate are clean & dry. After installing and test-driving it's always a good idea to check for tightness again. The M8 CV screws are known to come loose.

The M10 like Tippy has rarely come loose. I've tracked my '87 for years and every time I check the M10 screws, not one is ever loose. Not even slightly. However on my '79 racecar, every once in a while i'll see the paint safety marks slightly misaligned. It's a good way to watch your screws w/out having to torque check them all.

This season the '79 gets a new supply of screws with moon plates and serrated washers.

BTW the bell crank is part number 911.423.017.01

Pelican Parts - Automotive Parts and Accessories - Porsche & BMW

The torque spec for the screws is 30 ft-lb for the M8 screws and 60 ft-lb for the M10 screws.

[RJ911SC]

KTL thanks for the info, i have the lock washers , new gaskets, and will try the safety marks.
thanks for the part number on the bell crank

[JeremyD]

I put the stage 8 locking bolts on my car with the early transmission (only four per side)

Seems like good insurance.

[CaptainCalf]

I ordered a set of stage 8 locking bolts cuz the last thing I want to see is this kinda carnage when I grab a big hand full of second gear

[CaptainCalf]

Here's a pic of the Stage 8s

[cmcfaul]

Got you all beat on close calls. Saw a bolt in the driveway and said to my self, I know where that goes. Sure enough the remaining ones were loose. Reinstalled with new washers and a dab of locktite and so far so good a couple years later.

Chris

73 911 E

[porwolf]

Originally Posted by RJ911SC

Ok Stupid question time,
Would Lock Tite world or help?

Has anybody used epoxy in the threads? Bolts could be removed then with heat applied to the bolts with a torch. Seems to be easier for removal than red Locktite. Blue Locktite is probably too weak. Is that even thinkable for those CV bolts. I have done it in other applications but I don't know whether heating those bolts is practical.

[cmcfaul]

So far so good on the Lock Tite. I cleaned the threads and bolts as much as possible. Applied the lock tite to the bolt and the CV threads and tried to avoid getting grease on them.

my bolts protruce a couple MM's from the back of the CV Joint. I put a drop of lock Tite on the end of the bolt as well.

Just another layer of possible protection and I check them every time I look under there.

Chris

73 911 E

[Bonecrusher944]

just installed my new STAGE 8 LOCKING BOLTS after similar CV carnage at Sebring in my 944 S2 race car. Stage 8 reports zero failures ever. Anyone having good results with these bolts ??

[Tippy]

Originally Posted by Tippy

Hoy crap!

I can't believe this has happened to so many people.

Mine have always been tight.....maybe because I always put the "oil field torque" on them.....

Originally Posted by Tippy

As long as they are torqued to specs.

Removing them after Loctite will have you cussin'

Oh the irony of my posts.......happened to me recently and I WILL put Loctite on them.......

Same old story as others on this thread; grease flung everywhere, a few bolts backed out without damaging allowing to go back together to limp home, and the throttle linkage got a nice lashing.....

[RWebb]

the problem does not need to be solved with epoxy or Loctite or expensive locking fasteners

just [1] get all threads clean with brake cleaner, both female and male
[2] use moon plates
[3] use NEW Schnorr washers
[4] inspect the cap screws (bolts) carefully - both threads and the indent for the Allen socket (aka, wrenching fixture) & see [1] above
[5] torque properly
[6] check the torque later


this has been posted innumerable times here by Grady, Jim Sims, and on the CV thread that rececale (sp?) started, but it does not seem to have sunk in - maybe those threads should be made stickies and Emailed to everyone who joins Pelican with their authorization Email

[MysticLlama]

I have the Nord-Locks on mine and have been really happy with them. I can see how safety wire or stage 8s are another step above that, but that's also getting a lot fussier for install.

The torque needed to unlock the Nord-Locks and take the bolts out seems to be about 2-3x the amount you torque them down with, they hold really well. They are also reusable, and available locally more easily than Schnoors.



Once the ramps are locked together, they have to be spread apart to loosen at a different rate than the bolt pitch, which is what makes them hold tighter than a teeth only solution.

One thing to note if you think of switching is that they are thicker because of having two halves, and may require longer bolts. (Good to switch to new ones anyway)

[rw7810]

RWebb - I forget, but do the cupped side of the Schnorr washers face the moon plates or the allen head bolt ??

[RWebb]

Clean all grease out of the threads. Concave side of Schnorr washer faces away from cap screw head, toward the moon plate.

parts for mine:

Bolts, M10x48, 12.9 strength; 55 mm long overall; 48 mm from end to base of head; p/n 900-067-128-01; 4 bolts per side of each axle = 16 total

16 Schnorr lock washers, p/n 999.523.103.01

8 moon plates, p/n 911-332-191-00-M100

4 paper gaskets, p/n 901-332-297-00

you only need new washers and gaskets each time if the rest looks ok, as per above