New Owner, New Member, and a CV Boot Question (Pics!)
 

Hey all, I'm the proud new owner of a 2004 X5 4.4i. It's my first BMW (and the first car I've ever bought). I flew out to Chicago last Saturday, bought it, and drove it all the way back home to Northern VA by Sunday. It's Sterling Gray, with Sport Package, Premium Package, Cold Weather, 19s, Nav, and basically all the doodads except PDC (bummer). It's even got the slide-out load floor, which is a really neat feature that I'll probably never use. About 104k miles on the clock, but it's in spectacular shape inside and out. I absolutely love the way it looks, sounds, and drives. It'll be more adventure-mobile than daily driver, so hopefully I'll be able to keep it going for a very long time.

Xoutpost has already been a great source of information - I got a very fair price on an OEM tow hitch from BMW of Bloomfield, based on the recs from here.

Here are some pics taken by the dealer:
http://photos.ecarlist.com/BP/MR/2K/.../UT/kQ_800.jpg

http://photos.ecarlist.com/ms/km/In/.../Lb/yQ_800.jpg

I love the black interior w/ light poplar trim:
http://photos.ecarlist.com/ub/ly/vs/.../D1/7g_800.jpg

http://photos.ecarlist.com/L4/uP/KZ/.../IX/ng_800.jpg

Anyways, that brings me to my question. During the drive home from Chicago, I could hear a very quiet 'wum-wum-wum' noise coming from the left side of the car. The noise increases with speed, and it seemed to be one 'wum' per wheel revolution. I figured it was probably a wheel bearing on the left side just starting to go bad, because I've had that problem in other cars and it started out sounding similar. It's barely audible - you can't hear it sitting in the passenger seat. No vibration or tracking issues either.

Earlier today, I was talking to a friend who also has an E53, and he mentioned the CV boot issue they have. I went out and checked, and sure enough, both sides front outer CV boots were torn. They aren't gaping wide open, but they're definitely split, and some grease has leaked out.

So my question is, could the CV joints possibly be causing the noise I'm hearing? The noise doesn't seem to change with turning, braking, or accelerating - it just depends on speed. I've also heard the CV joint noise described as 'clicking', and this is definitely not clicking. It sounds exactly like road noise, only pulsing (like I said, 'wum-wum-wum').

It's important for me to figure out which one it is, because if it couldn't be the CV joints, then the joints are probably fine, and I'll just replace the wheel bearings and CV boots. If it is the joint, well, then I'll need to buy a whole new joint assembly (or maybe two).

Also, if it could possibly be either one, is there any way to check which is causing the noise before I start doing major dissection?

Thanks in advance for the help.

If its audible once its up to speed, and is like a wum-wum wum or just a loud humming (sort of making the wheel revolutions louder), its probably a wheel bearing with that mileage and age.

As far as I know when CV's go bad they start clicking and stuff. Personally, I have a 2003 with 66k miles and I have bad front wheel bearings believe it or not, my indy and I were just talking and he said he heard it when road testing my car so my next round of maintenance will be taking care of the CV's and the wheel bearings.

I'd definitely get a good indy to look at it if I were you, just to be sure.

As far as the axles go, if grease has leaked out of the boot and splattered under the car, personally, I would NOT re-boot the axles, I would replace them. You never know what grit, dirt, etc, has gotten into the CV joints. My personaly opinion is you replace the boots at first sign of cracking, but when grease leaks out, replace the joint to avoid any potential problems in the future.


Other than that, the truck looks beautiful. Do you know what recent maintenance has been done? I'd give a once over on the cooling system, make sure belts and tensioners are good, and do the differentials, transfer case fluid, coolant flush, etc just to know that your fluids are fresh.

As far as checking the wheel bearings, I've heard to jack up the front of the car, in neutral, and spin the front wheels to see if you hear any metal on metal sounds, although I don't think my car makes any of those, and to also grab the wheel at 9 and 3 o clock and pull in and out to see if there is play.

If you need axle replacement options, there are many options, depends on how much you'd like to spend. I've seen remanufactured cardones for 45 bucks, new EMPI axles for 55 bucks, all the way up to OEM/Raxle types for 250 per side. I'm still researching myself to see what the best options would be, since when I do both side wheel bearings I will take care of my axles at the same time.

Welcome... Nice ride! I bet you had a grin the whole way home from Chicago.

That wump wump sounds like a bad tire although it could be an axle. The reason I suspect a tire is that you're getting it once per rotation. If it was an axle or a bearing, it would make that sound more than time per tire rotation

I got my axle from ECS Tuning.... been in there for a while now with no issues.
OEM / Performance Parts for Audi, BMW, Mercedes Benz, Mini, Porsche & Volkswagen - ECS Tuning

Just to reiterate what you said, I replaced the boot on the left axle and a couple of months later, I had to replace the whole axle... wish i had just replaced the axle in the first place. With 110K on the clock, when the right axle boot goes, I'll be replacing the whole axle

Sockethead did you get the EMPI brand or the FEQ from ECS?

Thanks for the responses. Yeah, the drive back from Chicago was awesome. My girlfriend came along to help with the driving, but I ended up driving the whole way, it was just too fun to stop.

It's probably a good idea to replace the entire half-shafts and joints. I don't know how long ago the boots tore or how much the joints have been contaminated and damaged already, so it's pretty likely at least one will need replacement eventually anyway.

Is it significantly harder to replace the whole axle than it is to replace the boot (from a DIY perspective)? It seems like when you've removed enough to replace the boot, you've done most of what you need to do to pull the entire half shaft/joint assembly and replace it.

Also, anyone have any experience with the different brands/prices for the half shafts? The $40 to $50 ones seem almost too good to be true, considering what a substantial part they are.

FEQ. The design is a little different but works just as well. We're not easy on theX5 either so its had a good workout...


Yea, I'd just replace the axles since you have no idea how long the boots have been cracked and leaking... you don't want to have to do it twice like I did. You're right, you still have to break everything down to do the boots.
Don't forget to replace the axle seal on the differential while you have the axle out.

The first time I did it, it took a couple of hours, the second time, I had the axle out in 45 minutes. There are a whole bunch of steps you can skip.

This pic shows how you can take the hub off as an assembly instead of taking all of the pieces off. That's my front left axle 2nd time around. and that's the FEQ axle

http://i424.photobucket.com/albums/p...3/IMG_0880.jpg

Awesome tips socket, can you elaborate on the steps you can skip when getting the axle out in 45 mins?

As well as the differences in design between the FEQ brand and the EMPI brand, as I'm eyeing them both up.

Would taking the hub off as an assembly as you did help to make wheel bearing install/removal any easier?

Well, as you can see from the pic, you can save a lot of time by not splitting the ball joints... just take the bolts out at the other end. Also I found it un-necessary to take the rotor off. The axle came out of the hub pretty easy for me. I used a big brass drift pin and and a BFH to hit it. Getting the axle out of the hub can be a real issue.
The other part than can be a PITA is getting the axle out of the diff. I used a big ass pry bar and my foot to pop it out the second time. The first time I did it, it took a long time to figure out how to get it out without messing anything up, the sencond time I didn't think about that, lol.

OP, if you can change your own brakes, you should be able to swap out the axle...

RB, I've never seen the EMPI axle...only compared the FEQ to OEM... I'm not sure who makes the OEM