Update Carrera CV Boot replacement

88-diamondblue · 03-28-2007, 09:30 PM

This is continuation of this thread Carrera CV Boot replacement that I started when I replaced the CV boots on my Carrera axle. Thanks to Paul Ferradas donating his old Carrera axle I have completely disassembled a Carrera axle. The inner joint comes off the same as all the model years do. The outer joint is welded to the what would be the stub axle. I thought that the outer axle could not be taken apart. They can but not without destroying the tin to attach the boot too. The other reason for doing this was to see if a Carrera axle could be converted to use a turbo stub axle. The inner joint and axle are shared with the turbo and by using a new CV joint this would be a turbo axle. All that is verified by Porsche part numbers and diagrams. Only part that I have not been able to find is the tin to attach the boot to but could be sourced used from old axle assemblies. Ether used or new stub axles from a turbo would complete the conversion. A few shots of the disassembled axle.

This axle could have easily been rebuilt as there was no damage to the outer part of the cv joint. The inner and outer cv both had on worn lobe on each joint. Porsche's use of the crimped tin on the out side joint prevents rebuilding this joint.

The outside joint apart. There is a o-ring seal around the outside of the axle to seal it.

The outside tin is crimped on the outer axle. Tried heating with a torch and finally used a chisel to remove.

All the assembly parts.

KTL · 03-12-2009, 07:38 AM

I too had to mangle the snot out of the outboard CV tin to get a look inside the CV, to be able to see whether or not the outer CV is still in good condition. Well, the outer CV on my axle is in very nice shape- no galling of either inner or outer race. But there's currently no way for me to reassemble this joint and put it into use on a car w/out the outboard tin cover.

Somebody has to supply this outer tin shell/boot support. How else do reman companies refurb core axles and resell them?

88911coupe · 04-06-2009, 07:22 AM

Kevin, I'm sort of in the same boat as you. I've shot brake cleaner into the outer "sealed" CV and have gotten a lot of the old grease out but there's no way for me to disassembe it, other that destroying the tin piece that's crimped on to the stub axle. Not really sure what the logic was behind this design since the inner can be removed. I got referred over to this thread from Michael, aka 88 diamond blue, who was facing the same issue. What threw me off was comments indicating the outer tin piece could be tapped off but I guess that's for ealier models. At this point I'm going to just get it as clean as possible and repack, although it looks like you could possibly but the whole thing on a large lathe and just cut through the tin at the edge where it's crimped and then it could be removed like the other end. I would not begin to know where to start to do that though so it's basically a moot poing. Although I suppose I could get my angle grinder and try something....never mind.

88-diamondblue · 04-06-2009, 08:14 PM

At one time there was some one over on Rennlist that had a source for the tin on the Carrera outer axle. I spent a long time trying to find the thread that had the info on these. Never was able to find it again. There are others who have done the brake cleaner route and have not heard any problems with it.

KTL · 04-08-2009, 09:12 AM

THanks for the replies guys. Yes, there's no way to get this tin cap off the CV race without destroying it because it's crimped down into a groove.

I have no problem doing the cleaner solvent and repacking with grease and a new boot. The only concern I have is that you can't really see the condition of the race-ball contact surfaces, so you can't really tell if the joint is still any good to continue using. Of course as (un)luck would have it, my outer CV joint was in good condition upon inspection when disassembled. But unfortunately I can't put it back together without a new tin cap.

These late style axles are unfortunately not too rebuild friendly with that "special" outer CV with the integrated stub axle shaft....

Rot 911 · 05-05-2009, 07:34 AM

What year was the change to the crimped on cover?

KTL · 05-07-2009, 05:25 AM

Kurt,

The CV's with the non-bolted outer CV were introduced 1985.5

Rot 911 · 05-07-2009, 06:50 AM

Quote:

Originally Posted by KTL

Kurt,

The CV's with the non-bolted outer CV were introduced 1985.5

Thanks. Guess I better get that axle off and see if I can at least get the old grease out and some new in (torn outer boot).

KTL · 05-08-2009, 05:08 AM

With the axle removed from the trailing arm, you can pivot the axle quite a bit with the tin cover still in place. So getting the grease out is do-able. The only thing that bugs me is you can't get a look at the races to see if they're galled or not. I suppose if the CV feels smooth as you pull it axially, you should be able to feel if the CV is badly worn. Best way to check for smoothness is with grease removed, wouldn't you say?

Rot 911 · 05-08-2009, 05:49 AM

I agree Kevin, I wish you could disassemble to eyeball the races. But a good cleaning and repacking should keep it on the road! I am not sure if it would feel smoother with the grease removed or more sloppy because without grease you have more clearance between the bearings and the race.

J Smith · 05-08-2009, 01:42 PM

Check out this thread on Rennlist.

I just rebuilt my Carrera axles using Geoffrey's method of dis-assembling/re-assembling the outer cv joint. Worked great!

88-diamondblue · 05-08-2009, 02:31 PM

Looks like a great solution. I will need to check with the machinist that I have used for some other work and see how much this would cost to have done. You could judge the probability of the outer joint based upon the condition of the inside joint before having this done.

burgermeister · burgermeister's Garage

I seem to remember seeing this allen bolt fix someplace else on Pelican .. but I can't find where. I had 2 outer CV boots tear this year (on new lobro axles installed last year) ... very irritating.

I did mine with 6 M4x8 allen bolts. 3 probably would have worked just fine. I used a cutoff wheel to carefully cut the crimp off, tapped the cover off with a drift, and used a dremel to clean it up. Once I had the stub axle seperated, I tapped the cover back on. A simple "fixture" (2 sufficiently tall pieces of plywood screwed together with an appropriate width spacer) held it on the drill press. A hand drill would have worked too, but the drill press is easier.

I just tapped the holes with the cover still attached, and I added a dimple for alignment (I have no doubt those 6 holes only line up with one orientation). Obviously drill only where there is meat in the CV joint (6 places). It seemed pretty soft, no issues drilling or tapping.

The 4mm allen head interferes with the cover plate which will prevent the bolt from seating. I made a little tool to fix it. Basically I welded a 4mm allen bolt to a big nail (grind the nail tip so it almost fits into the allen recess, then pound it in with a hammer - that holds it well enough for welding), and then ground the threads off. Insert into hole on driveshaft, a few taps with a hammer, and voila! The allen bolt head now seats perfectly. I added some #2 permatex under the bolt head to make sure it's sealed.