oldskewel

I have a 1985 cab with a 915.68 transaxle (they went to 915.73 mid-year) and ~131k miles. No problems at all with the CV joints, but it recently occurred to me that they probably still have 24 year old grease in them (but I don't know the full service history prior to 1994 / 85k miles). I went under there yesterday to check things out, and the boots still look just fine. No visible leaks. Axles feel tight. I've replaced CV joints on my old air-cooled VW Vanagon, so I have an idea of how nice and clean a job it can be.

So here's the question: If possible, I'd like to just pump in new grease under the inner end of the 4 boots. That would seem to be at least 10x as easy as removing the inner CV joint + 2 boots and cleaning/regreasing. And since I have no problems seen, this is probably better than doing nothing. Does something like this make sense?

If so, any advice on how to do it best, type of grease to use, etc.?

Thanks, Ed

theiceman

it certainly can be done . I think pete suggested once slipping a piece of almost flatened copper pipe in there at the small end and squeezing in the grease.
Theproblem could be if you use an incompatible grease to what is in their you could break down the grease. I say you could squeeze in some moly 101 though ..

old man neri

I have heard of some people using a syringe to get grease in there. (This was not on a 911 though.

rusnak

With all due respect, I would take them apart. It's not a demanding job, just dirty. You need to know if your stub axles are separate before you can order the right replacement parts. I would also have a supply of new bolts and 24 washers.

ricster

I would think that after 24 years that lubrication is most likely broken down. I would take apart clean and re-lubricate. While your at it...I would exchange sides while your at it..so they wear in a different direction.

r911

take them off & replace with new/rebuilt if you need to

or DIY all the way

- you just need to do this ugly maintenance item every 20 years or pay a shop to do it.

- shooting grease will not get the old grease & grit out.

cal44

You guys are going to shoot me. I do the syringe. Cut a very tiny hole with a scalpel and insert the syringe end, no needle.
No....I am not a doctor. Just happen to have a bunch of items left over from my Army days as a medic.
rusnak is right..........the job should be done correctly.

Houpty GT

I am all about cleaning and repacking the CV joints when the boots have broken and are being replaced. If the boots are not broken and the seals and clamps are still there then I would leave them alone. I plan to clean and repack mine but only because a previous owner felt the need to do whatever he did to them and then not reapply the clamps. This has present the opportunity for water to enter the boot. This project still does not make it as a priority on my list.

I have never seen a oem CV fail when the boot was not broken. Front wheel drive cars have the majority of the problems since their CV joints are subject to increased movement due to steering. This also increases the movement in the CV during steering.

If it makes you feel better I would just repack CV joints the next time you do a clutch or other similar work.

I would like to hear if Pete or Steve have encountered any that needed replacement with original unbroken and uncontaminated boots.

theiceman

mine needed replacement at about 170,000 kilometers.

r911

If the grease is a few years old, then that's fine.

If the grease is 20 or more years old, then I would pay a little for prev. maint. and avoid a possibly big big problem.

oldskewel

Thanks for the advice, everyone. I did the job last week. Sorry to those whose advice I did not follow, but I decided to just inject new grease. The car is 24 years old / 131k miles. I've owned and maintained it for 13 years / 36k miles. Service records from the PO covering the previous 2 years / 10k miles. No known CV joint maintenance or problems during this time. In general, the car is mechanically almost perfect.

If anything needs to be done, I think I may be in need of a new clutch. So I figured I'd inject new grease for now, and do it right if/when I replace the clutch.

Thanks for the tip on the flattened copper pipe and syringe - the ideas led me to something that may be even better: I had a section of 3/16" OD hard brake line in the garage, with (I think) a 1/8" NPT fitting that came with it. This fit perfectly in my grease gun. So I was able to use it to inject the CV joint grease under the small end of each boot, with no flattening required. By feel, I think I was even able to get the tip up to the CV joint itself, sliding in an extra 1/2" or so, then pulling back out when rotating the wheel to another location. Hopefully this got the grease where it was most needed. Either way, I expect it is better than doing nothing.

jakeflyer

question: so you used a 3/16 od and inserted it under the boot? You must have undone the clamp? where did you get the grease, and what did you use to reclamp?

ricster

I think its more trouble than its worth...I would have just done the clutch and the CV'S

Steve Weiner-Rennsport Systems

If a very close inspection of the boots reveals no small cracks at the bottom of the folds, its likely that someone has repacked them and replaced the boots since they generally don't last 24 years,....

JMHO but based on experience, 131K mile CV's need more than a fresh injection of grease,.....they should be cleaned and inspected before they are repacked with grease and new boots get installed. Its better to be proactive about such components since the consequences of a failure is much more expensive than a set of CV's and boots.

retiredrider

My car is a '90 C2 - 964. I have the axle out to replace a bad rear wheel bearing and a torn CV boot. I have the inboard (transaxle) side off the axle as the circlip is easy to get to. How do you remove the outboard (wheel) side CV from the axle? It appears to be pressed on but I cannot tell where to apply a bit of pressure to remove it. I know that once I get the spline that goes into the hub removed that I can then get to the circlip to remove it and the CV joint.