Guys.. I've got these two hub's from a friend of mine which had his hub's replaced after he heard a "crunching" noise from the rear axle. I took one of the hub's apart and gave it a proper clean, and I cant really say whats wrong with it Anyone who knows what to look for??? The last pic shows you the inside of an uncleaned hub, in which was very greasy and messy. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Who told your friend it was the hubs that were faulty? Did he change them because someone told him to?
To be honest, I did + someone else, I had not heard the "crunching" noise so I just gave him a suggestion of what it COULD be. I then ordered 2 new hub's for him form the UK, they got replaced - and the "crunching" noise was gone....hmmm
If there's a bearing problem you should be able to find some damaged balls or spalling of the race surfaces. I don't see your noise in any of the photos. If it's a "crunching" sound the problem should be easy to spot on a bearing. If the noise is gone you apparently made a good call. How are the CV joints? Are the rubber boots intact?
Have look at the connecting flange. Some times the flange can get cockeyed inside the bearing race and wear a groove in it. At lease that is what happened to my car. Though I have an earlier 348 with a different axle hub. Anyway, with my car I was hearing a grinding sound when turning corners because of the stress place on one side of the bearing, and because of the flange being cocked. As a result, on one side the connecting bolts for my cv joint were knocking against the bolts for holding the axle bearing in place on the side face of the hub. The cause on one side was a piss poorly tightened ring nut. So take a good look at the shaft of the flange to see if it shows signs of wear.
This connecting flange looks flawless...to me.. The grooves are in good condition... Come to think of it, my friend never said he heard the "crunching" noise on both sides, so this COULD be a perfectly fine hub....for all I know. I havent cleaned the other one yet... Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
The inside teeth look okay, but there seems to be quite a bit of rust. Now how about the outside of it? The part that the bearing slides over.
When I put it together, like pic 3 - I can then turn the hub around perfectly, no noises or resistance what so ever (but that not under preasure/load though)...and there's no gap/space between the connecting flange and the utter bearing. The balls and the brown "ball holders" also seem to be in good shape, think I have to clean the other hub too...
It's not rust actually, is some sort of sticky goof of some sort, there's no problem to get rid of that stuff...
I've just finished cleaning the other hub, and I discovered this... these grooves goes all around. There were also a slight different color on the balls who have made the grooves in the pics. Maybe it's me imagine things, but something tells me the balls does not have the same size as the other set of balls....but it's extremely hard to really see IF there is any difference in size, and I havent got the tool to do the exact measure. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Pretty much what Pap said. New bearings and it "should" be good to go. But again, make sure that the axle connecting flange is in good shape before you fit new bearings to it.
May have also been a lack of grease or water in there as well..... the race is fairly blue, Low grease or water in there leads to overheating, Overheating breaks down the case hardening on the bearing races.... The bearings then proceed to pick at the races next thing you know bearing is RS. Looks like you picked it up in time, change some bearings (and check the hubs) and you should have a couple of good spares.
