Grinch threw up all over my rear right wheel/knucke :(

[2ss-booya]

Well I suppose things could always be worse, but today when I was adjusting my endlinks I noticed dark green grease all over the rear right of my car :(...Gotta take it in.


Any ideas what would cause this? defective part?

never been to the track.

[fastlane2010]

looks like an axle boot issue is there a hole in the cv shaft boot

[JDP Tech]

Gotta love that! Happened to mine and several others of us locally, but we were racing when it happened.
Don't be too hard on it until its fixed, or you may blow the axle like this:


I think its the poor quality boot GM uses, there isn't much flex in them so they split and spew when you're hard on it, especially when lowered.

We stabbed the above new GM axle in to replace it to get back on the track, and by the end of the day, the brand new one looked worse than yours does.

A couple of us had warranty take care of it, the rest upgraded to better axles with better boots.

- Jeremy

[PfadtRacing]

Yep, leaky boots are the cause of that. Good luck with the repair, since it doesn't look like you're lowered you shouldn't have too much trouble getting that covered under warranty.

By the way, nice trailing arm!

[JusticePete]

Originally Posted by 2ss-booya

Well I suppose things could always be worse, but today when I was adjusting my endlinks I noticed dark green grease all over the rear right of my car :(...Gotta take it in.


Any ideas what would cause this? defective part?

never been to the track.

Is your 5th Gen lowered?

[JDP Tech]

Its weird, 98% of the boot's I've seen like this have all been the right side outer boot...

Here was mine:

[JusticePete]

Originally Posted by Tech@JDP

Its weird, 98% of the boot's I've seen like this have all been the right side outer boot...

Here was mine:

Is your's lowered?

[JDP Tech]

Yes, mine is.

[JusticePete]

Heat.

When you lower a 5th Gen the half-shaft angle changes and with it the amount of heat generated increases. The OE grease liquifies at a modest temp. The boot is not designed to hold a liquid. It is designed to keep road debris a moisture out. When the grease in the joint gets too hot the liquid state 'grease' is slung out. When it cools you have Grinch Grease.

Half-shafts from reputable sources use a much higher temperature lube. Changing shafts changes the grease. The other option is to replace the OE lube with the high temp lube. There is a fair amount of labor involved for both.

With the unusually hot summer we had across the country there were an unusually large number of lowered 5th Gens that experienced this failure. It is generally restricted to lowered 5th Gens that are run on road courses. Don't ask how I know

[JDP Tech]

Exactly, though it was a particularly cooler day of racing (compared to others in the season) we figured it was the heat build-up from the length of sessions; each session was 40 minutes, instead of the normal 25 minutes. None of us had had a problem before the longer session days.
That, combined with the lowered cars and the extreme driving we were forcing caused it.
Most of us upgraded to some nice DSS axles, since now's the time to upgrade, when its broken, right?

I just find it odd it's the right boot on almost all of them...

- Jeremy

[Rock-It Man]

Inspect the boot carefully.

Since there was work done in the area, it could have been punctured by a wayward tool.

[ss/rs-matt]

So is there a solution to this short of replacing the entire axle? I just installed coil overs and Im about 2" lower than stock. If I can I like prevent this from happening. Suggestions?

[JusticePete]

Originally Posted by ss/rs-matt

So is there a solution to this short of replacing the entire axle? I just installed coil overs and Im about 2" lower than stock. If I can I like prevent this from happening. Suggestions?

If you plan on running road course tracks at speed for longer sessions, repacking the shafts is the solution. Use a very high temperature synthetic lube that will not liquify under load at higher temps. If you are lowering and will run an occasional 20 minute session you shouldn't have any issues. Unless you live in a dessert like climate. The solution would be the same.

[ss/rs-matt]

Originally Posted by JusticePete

If you plan on running road course tracks at speed for longer sessions, repacking the shafts is the solution. Use a very high temperature synthetic lube that will not liquify under load at higher temps. If you are lowering and will run an occasional 20 minute session you shouldn't have any issues. Unless you live in a dessert like climate. The solution would be the same.

Thanks for the info! Info plan on going to the auto club speedway or willow springs the next time speed ventures is in town. How hard is it to repack the CVs?