CV Bolts all sheared?!?

[Aerodynamic]

Just got this 1987 924s recently but a odd click from the right rear called for investigation. What I found was only one bolt remained, there was metal dust scattered and there was a mangled piece of metal on the remaining bolt.

Advice? What now?

[Spring44]

Finish removing your cv joint and the old bolt stubs and see what you have. If the cv joint is undamaged, repack it with grease and reinstall it using new bolts.

Pay attention to use proper torque on the bolts, as this is probably what caused the old ones to fail. Prior owner either over-torqued and weakened them, or he left them too loose and the cv joint hammered the bolt heads off under load.

If the cv joint is damaged inside, you'll need to replace it.

Check the operation of that wheel bearing too, while you have it apart.

[thomasryan]

When you get it apart, see if both joints are indexed on the shaft

If you look at the ends, the fat part of the inner spider should be opposite the thin side on the other end.

[IdahoDoug]

It happens when the bolts are not at the proper torque, or missing the lock washers. Too tight causes them to snap later. Too loose causes them to loosen enough for impact forces of movement to snap them one at a time. You caught it before the last one let go - good job.

No worries about the CV being damaged. It's way tough and this issue won't damage it. Just wipe out any dust/dirt on the end of the axle once you have it loose so you can swivel it to see that there is grease in it. Then get the broken stubs out and put on fresh correct bolts with the correct (Schnorr?) lock washers and you'll also want 3 new backing plates. They distribute the load like large washers and that piece of metal is the remains of one.

You dodged a bullet very well here. $40 worth of fasteners and you're back in business.

[Spring44]

I forgot to mention in my earlier post, but if you find spalling ( metal pitting where the ball contacts the cage) inside of the ball cage in the cv joint, you can just swap sides with your axles.

The axles are the same length and can be interchanged L to R and R to L. Changing sides reverses the rotational direction of the axle and so it also changes the contact area of the ball and cage and gives the ball a fresh surface to press upon. I did this and it works fine.

[9FF]

Originally Posted by Spring44

I forgot to mention in my earlier post, but if you find spalling ( metal pitting where the ball contacts the cage) inside of the ball cage in the cv joint, you can just swap sides with your axles.

The axles are the same length and can be interchanged L to R and R to L. Changing sides reverses the rotational direction of the axle and so it also changes the contact area of the ball and cage and gives the ball a fresh surface to press upon. I did this and it works fine.

Just an fyi, this only works on manual transmissions, auto trans have unequal L&R axles and the op didn’t specify a trans.

[Spring44]

Originally Posted by 9FF

Just an fyi, this only works on manual transmissions, auto trans have unequal L&R axles and the op didn’t specify a trans.

Yeah, thanks! I have a manual and never think in terms of automatics in a 944.

[IdahoDoug]

It also only works if you make the former inner end of the shaft be the OUTER end on the other side of the car. If you accidentally swing the axles around and cause the current inner end of the shaft (close to the transaxle), to be the inner end on the other side of the car you will accomplish absolutely nothing. Diagram this out to see why. Even experts make the mistake. I mark mine with a sharpie and be sure to orient them correctly.

Hope I got that right....

Doug

[Spring44]

Correct! I wrapped masking tape on the shafts and drew an arrow on them in the forward rotational direction before I removed them, because it is easy to get confused once you get them off of the car.
When I saw the need to reverse the shafts I just installed them with the arrows in the opposite direction.

[IdahoDoug]

Nice. Great solution. I do this on my Vanagon during CV joint services an it is sooooooo easy to make a mistake.

[DannoXYZ]

Originally Posted by Spring44

Correct! I wrapped masking tape on the shafts and drew an arrow on them in the forward rotational direction before I removed them, because it is easy to get confused once you get them off of the car.
When I saw the need to reverse the shafts I just installed them with the arrows in the opposite direction.

No, it's not rotation direction that matters, but the torque direction. Flipping axles on same side retains same twist direction and torque. You need to switch left <--> right sides in order to reverse torque on the axles. Inner/outer position doesn't matter.

[IdahoDoug]

Yes, Danno is right. I had to stop and think about it Switching sides is the only way to reverse torque.

However, it is best to make the former inner the new outer to spread the wear if one end gets more wear. For instance a front shaft has the outer CV getting more abuse due to turning. So making that the inner would be good practice. Thanks Dan.

Doug

[Aerodynamic]

Innermost section is stuck to the axle. Cant get it off with all my might. What now?

[thomasryan]

..with the clip removed?

[kdjones2000]

Remove the clip for sure then use a brass drift and a hammer to tap around it to get it to move...

[RKT951]

I had it happen once they do get loose but with lots of traction and loose bolt snap. I used stage 8 bolts so they dont loosen torque 5 lbs more if you use no gasket and the stage 8 bolts will fix the problem.

[curtisr]

+
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[DannoXYZ]

Be sure to clean off mating surfaces with acetone and be careful when installing not to get any grease between them. It's the bolt-tension that generates friction that keeps the two sides together and that friction transmits power across. Lowered friction from insufficient bolt torque or grease between interfaces allow slippage which breaks bolts.

I prefer blue loctite on the threads AND USE A TORQUE WRENCH!!! Torque spec is kinda high and it'll feel like you're gonna snap those bolts But that's really the correct torque. Grind 0.5mm off tip of cheesehead tool to make it wider and grip better. Also scrape all crud out of hole in bolt-head so tool can slip all way down.