CV Replace, But do I need new axles as well?

2003 330xi 113k. I was changing my oil the other day and doing my due diligence when I noticed that I will need to replace my CV boot on passenger side. Obviously I will just do them all. The question I have is that I've noticed a slight "clunking" sound coming from my front end when hitting small bumps under 30mph. While I had the front end up I looked at A-arms and everything that would be obvious, but no apparent slack anywhere. Upon crawling out I noticed that when turning the front wheels forwards and backwards there appears to be slack originating in transfer case. Do I need to just order 2 new axles and swap them out? If so which ones are the way to go. I've read that there are multiple options and I'm not trying to save some coin by doing this, I just want to do it right and put the most reliable ones in.

Clunking on transitions and broken pavement can be sway-bar links or bushings. Get a pro to diagnose rather than assuming the axles are toast.

Did you see a massive amount of grease on the inside of your wheels? That is the clear sign of boot failure which will lead to axle failure if ignored.

There was not an inordinate amout of grease in the rim, I just noticed a crack in the outer boot. The thing that leads me to believe the noise is due to impending axle failure is when I rocked the wheels clockwise and counter clockwise there seems to be more play than what I assume is standard. That, and the sound is coming from where the axle sets in the transfer case.

have a real close look at the sway bar end links. i had a small tear in the rubber housing that enclosed the bushing. that was enough to make a clunking on low-speed, smallish bumps that drove me crazy. i never would have believed that was the source, but it was. end links are super easy and inexpensive to replace, if i were you i'd be hoping that was it.

The easiest way to check the endlinks is to use a lever or piece of wood to pry up and down on the sway bar with the tire removed. You will see and possibly hear the end link clunk up and down at the joint.
The boots were still fine on one of mine, but both were toast and needed replacement. The new joints are very stiff compared to the used/worn ones.

The drivetrain is somewhat sloppy in our cars. You have 2 differentials and 1 transfer case, all with gears. My car has about 3/4" free play when you rock the tire/wheel clockwise - counter-clockwise. It does make a slight clunk, but this is normal.

Ok, it appears that the sway bar end links are responsible for part or all of the clunking sound. I ordered both sides (Lemfoerder) off of BavAuto, and will get them on asap. Took me forever to get my rims off of my rotors. Damn surface rust puts up quite a fight on those. When replacing the links would it be easiest to have them on ramps, or to use my jack and lift from the front center? I would have more room with the suspension hanging lower, but would that make removing the links more difficult because of the stress caused by the suspension hanging?

You will have to have the car on jack stands. I don't really see how you can get the upper joints loose on the end links with the wheels installed. Leave your jack under the car and put a stand under each side, that way if a stand fails at least your jack should help hold the car up.

Glad it was something cheap/simple

Good point Bobby, I guess I didn't think of the tire being in the way. Rookie mistake. I just figured with the strut compressed it would make life easier. Thanks for the advice, and yes I would've been using stands. I'm brave/stupid at times, but not crazy.

You can get them off just fine without taking the tire off, just makes it a little harder. You do need to have the load of the car taken off of the sway bar before you take off endlinks though. So jack stands are for sure the way to go.

Glad to hear it wasn't the axles and good luck!

Put some antisieze on the backs of your wheels before putting them back on the hub. And if you are ever changing rotors, put a dab of antisieze on the little retaining screw for the rotor. They won't be so hard to take off next time.

Originally Posted by drewseim

There was not an inordinate amout of grease in the rim, I just noticed a crack in the outer boot. The thing that leads me to believe the noise is due to impending axle failure is when I rocked the wheels clockwise and counter clockwise there seems to be more play than what I assume is standard. That, and the sound is coming from where the axle sets in the transfer case.

The axles don't "set" in the transfer case. They are seated in the front diff. Did you mean the diff? Or is there something going on with the transfer case?

-G

Hey G, yes I did in fact mean where the axles set inside of the diff. Bv the transfre case transfers power to the diff which in turn transfers that power to the driveshatfs and ultimately the wheels. There doesn't seem to be any issue with the transfer case, but I should probably do a fluid flush/change soon since I am at 113k.