Flange Wear from CV Joint Options

[frank_c]

Today I started the process of dropping the engine & transmission so that I can send the transmission off to Dr. Evil and take care of some misc engine work (rear main seal, oil return tubes, etc. ). As part of this work I was also hunting for a clunking noise I hear from the back when the car is stopped and as I let the clutch out and the car just starts rolling forward. I already checked and/or replaced all suspension and engine mounts, as well as the outer CV joint bolts (inners are safety wired) and found nothing loose. So next on my list was either the CV joints themselves, or possibly loose flywheel bolts.

When I removed the inner CV joints from the transaxle flanges, I was surprised to see some pretty deep gouges in the flanges from the CV joint inner race/star (see photos below). This seems like a good candidate for the noise I am hearing.

I have never seen this type of wear before with any of the other cars I've worked on - what would cause this? I noticed that there is not much grease in the joints, which I suppose is one possibility. Was the inner race put on backwards? Wrong parts? I did confirm that the axle shaft does move in and out freely at the outer CV joint.

Thanks for any insight.

Left flange:


Right flange:


Circled area shows where inner race is cutting into the flange.

[Jack Standz]

"I have never seen this type of wear before with any of the other cars I've worked on - what would cause this"

Typical wear from 50+ years. Replace (CVs, axles, etc.) worn parts. Lately, we've been replacing with PMS flange adapters and Carrera axles (930 CVs) due to the fact that original style 914/4 CVs aren't available.

[Superhawk996]

That isn’t normal wear. The CV spider should never be plunging far enough to come into contact with the flange.

You have some sort of mismatch somewhere.

Possibilities:
CV joint was previously disassembled and not reassembled properly as you speculate.

Flanges not correct / not seating deep enough into differential?

Axle shafts too long?

Wrong CV’s - maybe someone using the wider 944 CV’s without proper machining mods to 914 axles? (Not sure this is possible without doing the axle machining to get the CV onto the axle)
http://www.914world.com/bbs2/lofiversion/i...php?t80641.html

Don’t know if you’re running non-stock trans position / angles / ride height that is resulting in too much axle plunge?

[bdstone914]

That isn’t normal wear. The CV spider should never be plunging far enough to come into contact with the flange.

You have some sort of mismatch somewhere.

Possibilities:
CV joint was previously disassembled and not reassembled properly as you speculate.

Flanges not correct / not seating deep enough into differential?

Axle shafts too long?

Wrong CV’s - maybe someone using the wider 944 CV’s without proper machining mods to 914 axles? (Not sure this is possible without doing the axle machining to get the CV onto the axle)
http://www.914world.com/bbs2/lofiversion/i...php?t80641.html

Don’t know if you’re running non-stock trans position / angles / ride height that is resulting in too much axle plunge?
@frank_c


I agree with the above reply. Never seen that wear.
Is it both sides? Have you pulled the axles and checked to see if it happened on the outboard CBs?
Need to look at nothing sides of the center of a cv to see if that could happen from wrong installation.

[914Sixer]

It is a rare but I have seen in before in stock axles.