carfreak967

Hello all, i recently got an 01 WS6 in Feb with 72k miles, and did the typical fluid changes including rear gear oil. car has 77k now, and i have been noticing a slight rumbling type noise from the rear. kind of sounded like a rear end related noise, but had a slight oscillation to it that increased with wheel speed. based on the frequency i narrowed it down to either carrier bearings or axle bearings. i jacked it up and let it roll in 3rd gear, and couldnt really pinpoint the noise, but it seemed possibly just as loud or louder near the wheels. it sounds "deeper" than a dragging caliper though, and i confirmed that the rear calipers float freely.

i decided to crack the case back open and pull the axle shafts to check the axle bearing (best case)

the inside of the case looks fairly normal (to me) with a little bit of fuzz stuck to the magnet, but upon pulling the driver side axle shaft, i found scoring along the axle surface where it rides on the bearing. i will attach pictures shortly.


But was odd to me, is i found little clumps of what appeared to be black RTV silicone (which i used on both sides of the gasket when i put the cover back on)

RTV was nowhere inside the case, just in the axle tube. im thinking perhaps those two holes in the mating surface of the case (that look like they lead to the axles) could have gotten some excess RTV in them when i bolted the cover down?

the gasket did not have any provisions for these holes, so thats why RTV would have been exposed to this hole when i bolted the cover back on.


so, my questions are:

would some floating RTV turds cause the bearing to freeze up? or do you think it was unrelated? the rollers seem fairly smooth, but obviously something must have went wrong at some point.

is there anything special to look out for in terms of these axle holes while i am installing the cover/gasket/rtv?

and, it dosnt look like my driver axle shaft really lost much material, it just has a rough/pitted appearence to it. possible to clean this up? or will i need a new shaft? (will have a pic up soon)



thanks for the help guys!

-Ryan

carfreak967

Here are some pics

01ssreda4

iTrader: (96)

If its pitted replace it, anything else is a bandaid. Lots have had issues with the "fix it" bearings that move the bearing surface inward a tad to get you on fresh metal. I would recommend against those as well. What you saw was probably a coincidence unless you globbed the heck out of the rtv.

carfreak967

thank you for the response.

any suggestions for repairing this so that i will not be hearing this noise again in the next year? lol

as for the RTV, i just found it was in close proximity to the axle bearing, so figured i would ask if this could have caused it.

so does the wear on the axle in my pictures look to be abnormal? is this possibly the cause of my noise?

i was not sure if they were supposed to look like this, or be smooth and shiney when removed, figured i would post up and see what is "normal" and what is "bad"


if this is a "bad" axle, what should i use for a replacement?

thanks!

BMR Sales2

iTrader: (40)

The correct way to fix it would be to replace the axle with a new or used axle (in good condition of course) and install a new axle bearing in that side. The RTV probably didn't have anything to do with the bearing failure and even if it did it would be very minimal at the most. The wear on your current axle looks normal for a car with a bad axle bearing. That area of wear on the axle where it rides on the bearing would normally be smooth and not discolored if it was in good shape.

The only way you could reuse your current axle is with a "fix-it" axle bearing but they can be a pain and don't always work like they should so that is why I would recommend replacing the axle along with a regular axle bearing for the car.

carfreak967

ok that is what i was looking for. i have yet to pull the pass side (will do after work)

but if you had to guess, if i replaced both axles and both axle bearings, should this quiet my rear end down?

i would just hate to put a lot of money into trying to quiet it down, and have it still sound the same afterwards.

especially because i plan to swap to a S60/9" rear at some point with this car.

will a 98 axle with 3 channel abs work? will the ring swap over to the 98 axle?

01ssreda4

iTrader: (96)

First, yes the axle is a paper weight. Its fucked. If it was me, I'd source a used one here or off eBay. You need a 4 channel axle because it has a shoulder for your speed gear to press on. Preferably, I'd buy one with the gear still attached so its a drop in and go type of deal. New bearing, new seal, used axle, you should be good to go for another 100k.

carfreak967

What is involved in pressing the rings off of my axle and on to a new one? What about wheel studs? only used ones I can find locally is $50 For a set of 3 channel axles off of a 98 (craigslist) or summit racing has some options for 200-300 a set. Parts stores want 200 a piece and it's a special order.

carfreak967

Also, for $50, what happens if I ran the 3 channel shafts? Would they fit and just disable traction control?

01ssreda4

iTrader: (96)

Yes, the 3 channel axle will fit but abs and traction control won't function. You can heat and pry your old ring off, but only designated 4 channel axles have the shoulder for it to sit on. 3 channel axles are molded slightly different where the ring mounts.

carfreak967

Thank you. Luckily I found another set of axles for $40 and am in the process of swapping the bearings. The pass side axle turned out to be fine, but I'll put 2 new bearings/seals in regardless. Hopefully just having that one scored axle was causing most of my noise, but I'll follow up with the results soon

01ssreda4

iTrader: (96)

I'm sure you will have no issue from here on out. Good luck.

SparkyJJO

iTrader: (11)

My old car had one axle look like that and it made a rumbling/roaring noise. I did the same with new seal, new bearing, used axle, and all was good after that.