Noisy Axles, Is there a trick I don't know about? Options

[John]

This past weekend, I did my first track event of the year (have been doing them for the last 18 years).

I started hearing a clunking noise from the rear. It sounded like it was coming from the Left Rear (Driver side). I checked it out and the only thing I could find was that if you grab the axle shaft and vigerously shake it side to side, the axle shaft will bottom out and cause the clunking sound I am hearing out on the track.

What I believe has happened is that there is no grease left at the end between the stub shaft and the end of the axle to cusion the shaft movement.

Here is part of my problem. I bought the axle shafts from Patrick Motorsports 2-3 years ago when I did the 915/916 transmission, and they are different axle shafts. The stub shaft is connected to the CV joint and the other CV joint (tranny end) has a sealing cap crimped to it. I don't know if it is perminantly attached, or if it comes off.

Are the axle shafts worn out when you can move the axle shaft like this, or do they need grease. If they need grease, how do I get the grease in where I think they need it?

The only changes I made to the rear suspension this winter was to lower it about 3/4" (axle shafts are horizontal), increase the spring rate from 350# to 400#, and align it. I have checked everything out and nothing is loose.

Any ideas, suggestions, or wisecracks welcomed.

[ArtechnikA]

QUOTE (JOHNMAN @ Jul 9 2005, 08:00 PM)

If you know how to dissassemble the outer portion, please enlighten us, as these axles are not cheap.

some FWD cars used a similar CV, and had a circlip that could be used to release the joint from the axle. you might look for such a mechanism on those, but my understanding is that they are, indeed, not dis-assemblable. you'd hope there's some documented way of cleaning and relubricating them but i don't know what it is. i'd guess that hot-tanking it, with an ultrasonic cleaner to break up the dead grease, would do it, and grease re-introdued to the joint through a really thin tube.

it's possible that they're considered "lifetime" jints, in which case, you kinda hafta hope there's really good grease in there.

but the outers don't have nearly the issues the inners do. i'd guess that if you disassembled your axle joints, you'd find that the outer is still in pretty good shape but the grease in the inner is dead.