CV Joints - Rebuild or Replace?

[jcsjcs]

Hey all -

I am in the process of having my Transmission rebuilt. When I removed the CV Joints, the ball bearings fell right out.

Is this a problem or can I rebuild the CV joints? I have heard that the rebuild can be a bit challenging - like a Rubik's cube.

Looks like new CV Joints would be about $320.

Parts to rebuild including boots are about $60.

I have an '84 911 - apparently things changed a bit in 85.

Any advice appreciated.

[Superman]

Nearly all of the CV joints I have inspected were worn. Many were pitted. In my experience, it is fairly rare to come across CV joints that are fine and can be cleaned and reused. I think that if someone disassembled, cleaned and repacked them annually, they would stay fine for a long time. But nobody does that. Used, worn ones can of course be cleaned and repacked. And generally they will provide service. So....I guess it is up to you. My advice, if you can afford them, is to simply replace. Or clean and inspect. Look at the wear surfaces on the races. Pitting is bad. A little wear/discoloration is acceptable. They are not difficult to disassemble and reassemble. There are pictorial, step by step instructions. Probably posted on this site somewhere. Not difficult at all to disassemble and reassemble. Messy, but not difficult.

[MT930]

If they are in fair shape rebuild

If they are heavily warn replace.


Some excellent threads on this are easy to find with the search function.
Type CV Joints

Rebuild is not bad, it is very greasy.

You will need
2 Roll paper towels
5 pair of rubber gloves
Half gallon of lacquer thiner (Cuts the grease)
Brake Cleaner
Metal cans or bowls for soaking

This the best one I have found.

Reconstructing Constant Velocity (CV) Joints

It not that bad, spend some time reading the CV threads they contain all the fine points.

[RWebb]

take some good closeup pics of the ball bearings & of the cages - post

or just buy rebuilt ones if $$ is not that big an issue

[Bob Kontak]

Everyone is correct in this set of threads. It is like a Rubick's cube. It is greasy. It is not difficult.

But it will suck time. Lots of time for the DIY "noob" (like me) doing this job. You can't really put them back together wrong as they will not pivot freely. They will freeze.

I would suggest to scope it out before you buy the gaskets, seals and grease. Clean them up and see if there are heavy wear marks on the thrust surfaces. Slight wear marks are ok.

If I had to do it again, I would spend the money and get new.

[midnight911]

the bolts, people...the bolts...

since yours is 84, I suspect you did not see any washers with the six hex bolts holding the CV to the gearbox and hub flunges. getting the bolts in grease free is near impossible but i encourage you spend time and try.
also, get moon plates and schnorr washers if you can.

M8 Schnorr Safety Washers P/N~?? (CV thing)


besides that, rebuild and repack. CVs can go many many miles.

[jcsjcs]

Thanks - will update you all this weekend with pics.

[Justin@Athens]

An entire new rear axle is only $420 if you go genuine Porsche. You can get one on this website for $320 from GKN and not worry with the grease! 911-332-024-15-M60

[sparkle84]

As to grease free bolt installation, this works pretty well:


Clean bolts 1st
Install all bolts & tighten to 5 ft/lbs less than spec
Remove 1 bolt at a time, clean hole with brake cleaner & compressed air
Clean, dry & reinstall bolt
Final torque & you're done fairly quickly & without too much mess.

[d.a.autry]

BTW, I don't know if the link provided above states this. . .I haven't checked it out, but there is a way to redo these (as long as no pitting on the balls or 'races' (if you can call them that) to where you can get the balls to ride on unworn areas of the outer and inner rings. Once you get one clean and figured out, you'll see what I mean.

[snbush67]

I dissagree with MT 930 above: You will probaly need at least 3 rolls of paper towels.

[jcsjcs]

Pics - as requested. I am leaning towards cleaning and repacking - due to other projects I have to complete right now. Open to suggestions on this....

Seems to be some wear - balls look perfect.

[RWebb]

looks like minor wear but not too crazy re the color changes...

what does it feel like to your fingertips? to your finger nail?

[jcsjcs]

Feels very smooth. There is a very slight rounded indent in every other "track" (don't know what to call them.) The indent is not deep 1/10th mm or so?

What's the risk in repacking these and using them?

[TechnoViking]

IMO, this is not only a financial decision. What is your threshold of pain for doing this kind of project?

Do you plan on having them off again, say, next year for an engine drop or bearing replacement? If so, rebuild the CVs and drive them 'till they break.

If this is something you want to do once and drive the car for the next 5 or more years, trouble-free then buy new. CVs are a PITA, especially the kind we have. I have never had one come loose, BTW, after careful re-torquing after driving a bit. I get grease everywhere when re-assembling (like most mortals) so don't sweat it.

[RWebb]

very low risk - some just run them until they get noisy - yours weren't, right?

the real question is the $$ vs. the fun of R&Ring them again sooner than if they were new ones

[jcsjcs]

Thanks for the advice. Mine were not noisy and I would rather spend the $250 saved (or so) for just CVs OR $400 saved (or so) for axles on other more critical stuff right now.

I only drive 3 to 5k per year - so I think these will last awhile!

[d.a.autry]

Originally Posted by jcsjcs

Thanks for the advice. Mine were not noisy and I would rather spend the $250 saved (or so) for just CVs OR $400 saved (or so) for axles on other more critical stuff right now.

I only drive 3 to 5k per year - so I think these will last awhile!

Again, I'm sure you see what I was talking about now as far as arranging things to run on unworn surface areas. I've done this on several CV's, even a pair of really noisy ones on a 44, got an additional 100k out of them after doing so.

Good luck and have a blast!

[jcsjcs]

Does the order of the ball bearings matter?

Do I need to install the same CV to the same side of the car?

I am not quite sure if can backtrack and figure out what went where exactly - but don't want to create further problems due to wear patterns.....

Immediate Advice appreciated - as I want to start tearing these things apart tonight!

[snbush67]

Originally Posted by jcsjcs

Does the order of the ball bearings matter?

Do I need to install the same CV to the same side of the car?

I am not quite sure if can backtrack and figure out what went where exactly - but don't want to create further problems due to wear patterns.....

Immediate Advice appreciated - as I want to start tearing these things apart tonight!

It is always best to put it back the same way it came apart. But I would not go so far as trying to match the bearings back to where they were. If you notice there is a small groove around the circumference of the outer assembly. Note if the groove is inboard or outboard, that is how you want it to go back together on the car. I would recommend you dry assemble, check for proper movement and rotation, then pack with grease. Also make sure you torque the bolts to 32 foot lbs. in an alternating sequence.