Despite the greasy mess, I've got four new joints in place without a hitch. Hey, my clunking sounds are gone - go figure.

Just so I keep these guys in good shape, does anybody know the recommended regrease interval. I thought I read somewhere about every 30K miles, but I can't find that reference anymore.

Anybody ever replaced a differential flange gasket? I think my seal on the passenger side is leaking a little. Haynes makes it sound pretty straight forward. Anything I should watch out for?

 

Tom, as long as the boots stay intact, I'm unaware of a recommended re-grease interval. Regreasing would require boot replacement, or at least the clamps. I think the grease is pretty well good for the life of the boot.

On the 944, my wrench suggested replacing the boots at about 80K miles. He cleaned the joints then & packed them with new grease. They were still doing fine when I sold it at ~110K.

Any time you're under the back of the car, look for thin lines of grease on the underside, slung out in the plane of rotation of the joints; that's a sure sign of a cracked boot. This inspection probably should be part of regular maintenance for all of us, at oil changes.

Then there was the Jetta he fixed for a guy who was broke; had to get to Miami for a family funeral. Injected new grease thru the cracked boot, and wrapped it all in duct tape. It made it there & back, and was driven around town for a couple of months before being properly fixed. The joint was _still_ good!

Jim, thru the AM fog.....literally & figuratively...

Jim,

 

One thing you might want to do is wrap the section of your exhaust that passes over the driver's side axle with that heat-retaining exhaust wrap stuff. The heat from the exhaust toasts the driver's side axle.

Bryan

 

Jim, my original boots did not have the clamps you speak of that clamp the boot to the axle, and I don't have the proper wrench to crimp the ones I got with the CV joint kit, so I didn't put them on (I tried with a regular pair of pliers to no success - the clamps appear to be too small). The boots fit very snuggly over the axle, so why do I need these clamps?

On that note, why is it necessary to grease the inside of the boot? None of that grease is going to help the joints. Is it just ot help keep the boots lubricated from drying out?

 

Hi Tom
If they look loke the OEM clamps, I use modified carpenters pliers, grinded the cutting edge off, worked fine so far.
To prevent any water & debri to get in to the boot (capillary gaps make water flow faster than you can even dream of).
You got to have them. Taking them all apart again for some clamps seems like s bit of a waste, so I suggest using the chemical resistant type of ty-raps (black with stainless lip) for now.
No. I think Jim ment that the content of grease last longer than the boot. This is also acc my experience.

CV joints normally last till the boot cracks open and the debri get in there. Boots are the limiting factor (for us normal mortals driving along with less than 300 HP that is.... )

 

I can still wrap the special clamps (or other types of clamps) around the boots and tighten them without pulling the axles.

Hans, if I don't need to grease the boots, why do the instructions (Excellence, Haynes, packaging the CV grease comes in) all say to place the remaining grease inside the CV boot?

 

Tom, just a guess on the extra grease going into the boot... probably to keep the grease in the joint itself from just slinging out into the spaces in the pleats in the boot; makes sure that as the boot flexes with suspension travel, that some grease gets rubbed back onto the mechanical part of the joint. But it's _strictly_ a guess....

Jim, of course, it also helps keep the inside of the boot nice & shiney for concours judging... .. make sure y'all only use _factory_ grease there, now...

 

On my dad's 500SLC the grease is more of a liquid than a gel, the grease in my CV's and boots was like play-dough but the boots were good, I put in synthetic CV grease (and new CV's).

 

Just that.
If you only fill the CV, the grease will travel to the boot in time, leaving not enough in the CV.
Just do not over fill the boot. there should be some air for expantion in there.
Tom, If you can get the clamps on, than that is definitively better than ty-raps.
I think the ones you have are "hose clamp"types with a little lg that needs to be squeezed in the neck of the lug. (more or less OEM style).
The tool for the squeezing I use is the modified carpenters plyers (or when in rush: steel wire cutter make Channelock, just between two fingers...)
Take care

 

I still don't get the logic on this. Whether you put grease in the boot or not, the grease in the CV is still going to work its way out/off of the joint over time. In fact the boot area is offset from where the flange attaches to the joint so the two are totally separate issues.

Skip, are you there?

 

My understanding of the "as much grease as possible" is to eliminate a lot of air in the boot. The CV drivers side, inboard, passes near the exhaust, and can get hot. If there is a significant air pocket in the boot, it heats up, expands, and pushes the grease out thru the band seals. I've seen this one firsthand. I've also heard that some people actually ad some sort of pressure relief valve to the boot to eliminate this problem, but it would be tricky to do without compromising the seal and or boot. With this problem in mind, there is no such thing as too much grease. (until the boot starts swelling!!)
IMHO

 

The seal on the stub axle is easy to replace. Remove the bolt from the center of the axle (after removing the CV joint) and the part will slide out. The seal is right there. You will probably lose transmission fluid (I did mine when the transmission was out if the car) so check to be sure the fill plug can be removed before you start.