WHeel bearing/axle/whatever it is post part 3 - PeachParts Mercedes-Benz Forum

The Warden · #1 01-04-2003, 01:07 AM

I'm about ready to set fire to the car. (yes, I still love my oil-burning Benz; I'm just real frusturated right now)

I got the axles removed and replaced; it really wasn't that bad of a job. However, the noise is still there. It's a roaring sound that I've always associated with a wheel bearing going out, but both rear wheels felt to be moving okay. I took the lug wrench to the wheels to make sure everything was tight, and noticed something weird with the front left wheel. On putting pressure on the wrench, the whole wheel moves back, more than I've seen on any other wheel. It doesn't always do this, and seems to only do this with the wheel on the ground. I can't get the tire to do this when the wheel's in the air, and with the tire off, I can't get the brake rotor to move at all up or down or to either side, although it seems to be spinning normally.

I tried the spare tire, with no change. I did notice that the weights were missing altogether on the original wheel, and was missing on the outside of the spare tire wheel.

Could an out-of-balance tire be making such a noise? If not, any ideas? I tried to get the grease cap off to see how much grease was in there, but it wouldn't go.

Any thoughts would be greatly appreciated; I'm getting real frusturated...thanks in advance!

engatwork · #2 01-04-2003, 07:13 AM

Warden - this is one of those that is hard to make a guess about without actually being there. I'm wondering if you are hearing differential noise. When you had the diff cover off did you take a close look at the ring and pinion gear teeth? They can tell a good story. Either look at the library or you may find it on the net somewhere but there are ways to look at gear teeth to tell if the gears are making "proper" contact. If they are not making proper contact it is very well possible that it can be noisy. Keep in mind too that a diff can go for thousands of miles while making alot of noise.
I am not sure about your wheel movement. That sounds like suspension issues. Does the noise "come and go"? Is it affected by speed? It could be the tire making the noise as it "moves".
You may want to put the rear of the car on jackstands, put it in gear and see if it still makes the noise while the rear wheels are turning.
Don't give up yet.

The Warden · #3 01-04-2003, 05:49 PM

The noise doesn't "come and go" at random, but it is affected by speed. I can't really hear it below maybe 5mph or so, and from there it gets steadily louder until about 55 or so, where it seems to disappear. It could be tires making that noise; it could be compared to a 4x4 with mud tires driving down the freeway, but not quite that loud. I'm pretty sure it's coming from the front end'

My dad thought that it might be a wheel out of balance, so I took it to a shop this morning. They balanced all the wheels, and it made no difference, but they did find something. The sway bar connects to a bar going down to the hub, and also attachs to a bar that goes towards the center of the car and bolts to something; I couldn't tell exactly what but you can access the bolt holding it on from under the hood after removing the air cleaner. I don't know what the bar's called, but it's maybe a foot long. There appears to have been a rubber bushing there, but the bushing's completely gone.

I'm guessing that this is affecting the alignment, but could this be making the tire not be in exactly the right place, making the tire make that noise? I was told by the previous owner that the sway bar bushings needed to be replaced, and have always heard a clunking from the front end, but haven't heard this noise before. Maybe something got worse?

The people at the shop were convinced that this was the problem, and said that this'll eat up the tires but won't do any "real" damage. They also said that the wheel bearings were fine. I think (hope?) that I can drive the car home like this, especially since I need to get home today.

Assuming that this is really the problem, what's that arm/bar called, so I can know what to ask for? Also, should I stick with rubber or is polyurethane an option, or what?

Any thoughts/imput would be appreciated...thanks!

{added in edit} Also, in addition to the noise, I do feel a little bit of vibration in the steering wheel; I didn't think about this until yesterday as I'm used to it due to driving mainly 3/4 ton trucks prior to this car...I had thought it was normal...

gs sparhawk · #4 01-04-2003, 07:39 PM

Warden, I hope we get a lot of input here since there is a lot of what you describe going on in mine . I've been hoping that it gets worse and breaks so I can find it.

billrok · #5 01-04-2003, 09:16 PM

The problem, in my opinion, with your car is not front end related at all. You have a bad pinion bearing on the differential. It's the front bearing just behind the yoke. Based on your description, I think that's your problem. Especially if it only shows up at speed and is somewhat speed sensitive. I remember reading about this problem with the 126 or 123 Chassis cars on a past thread. As I recall you just live with it until it's unbearable and then prepare to open your wallet.

The Warden · #6 01-04-2003, 09:35 PM

Bill, if the differential pinion bearing was the culprit, why does the noise sound like it's coming from the front of the car?

Some other things I've noticed are that the noise quiets down a LOT when the brakes are applied. Also, on curves at freeway speed, the steering feels real squirrely. I think that this is something that's been steadily getting worse but that I hadn't really noticed before.

Any thoughts would be appreciated. Thanks in advance!

{edited to fix lettering}

zbenz · #7 01-04-2003, 11:45 PM

I have one thought it could be a loose upper ball joint. I had a triumph spitfire that did just what you describe. When the car was up there was enough pressure to make it feel ok. Also higher speeds forced it tight, but under 55-60 it was loose and made the tire make noise as it wobbled. Just sharing experience.

gs sparhawk · #8 01-05-2003, 12:43 AM

If you dont loosen the brake pads off the discs, any spindle bearing looseness will not be very evident by shaking the wheel. However, when I took my hubs off, the bearings looked great and I was very impressed as to how much more refined those looked than my usual GM etc cars. No wonder these cars drive so nicely.
My driveline center support bearing may be my culprit and the vibration could appear to be coming from anywhere under the car. I replaced the one on my 280 and it wasn't too bad after I figured out which end went where.
But, now it's coold and I don't want to get my tender body down on the concrete and under the dripping chassis.
So many noises--so little ambition.

Sparky

The Warden · #9 01-05-2003, 04:48 AM

One other thing I noticed, on the drive home, was that on a lefthand curve on an offramp at about 40 or so, the noise either went away completely or got quiet enough that I couldn't hear it.

Not sure what that means; too tired to think...but I'm home and in one piece and am going to bed.

240 Ed · #10 01-05-2003, 08:35 AM

Warden,

Are you back in the bay area now? You sure get around!

You might be hearing the wheel bearing at that wheel, because there is NO RUBBER on the swaybar to isolate this component.

So, when you are going down the road, you hear the whirring of the bearing. When you turn, your sway bar will naturally lift (and it will now be free, not touching the frame anymore) so the sound goes away. Same with braking.

Here is what you can try.
Try putting some kind of insulator inside the sway bar bracket (the one with the missing rubber). You should be able to squeeze in a piece of rubber, say, a cut up piece of bicycle tire (the tire would be thicker than the tube, although you could fold up tube to make it thicker...)

If the noise goes away, you have at least solved the mystery.

But the real problem here is, that your whole front end is probably extremely worn out!
If you MISSING a rubber bushing from the sway bar, the rest of your bushings are probably very loose/sloppy.

The Warden · #11 01-05-2003, 04:28 PM

On the front end, I've decided that the car's out of commission for the moment anyways; I probably shouldn't have driven home (yes, I'm back in the Bay Area now

), and if my back can handle it, I'm gonna be driving the truck for a while (probably a good thing; my truck doesn't wanna play driveway king; it wants to work!). I don't have a problem replacing all the rubber; I guess the big question is first, what do I need, and second, should I stick with rubber, or is polyurethane available or a good idea, or what?

Also, this is unrelated, but is it possible to tighten the steering box? I don't know if this is new or what (again, I never really paid attention before), but the steering wheel has a good 2 inches of play...don't know if that's all in the box yet or if there's something else that's worn out...

I'll probably pull the grease caps off the bearings and check them both out; I need to replace the brake rotors anyways...

#12 01-05-2003, 08:31 PM

Yes, you can tighten the steering at the box. If I remember right you have to unscrew (ccw) the bolt to tighten the steering. I did mine right after I bought it and it took all the play out of the steering. Good luck, lee

240 Ed · #13 01-06-2003, 04:47 AM

Right you are Lee! CCW.

I don't think it was particularly dangerous driving it home, but a worn front end is a potential danger from the fact that it needs "tending" to keep the car going straight. And that is a tiring chore and might lead to problems in a moment of in-attentivity. (Is that a word?

)

Besides, you are not receiving the benefits, the magic, of the Benz experience! They drive great when set up proper!

The Warden · #14 01-06-2003, 04:51 AM

Quote:

Originally posted by 240 Ed
Besides, you are not receiving the benefits, the magic, of the Benz experience! They drive great when set up proper!

You mean that my 300D's not supposed to drive like a smaller F-250?

Show me more!!

Again, what all needs to be done? As before with the axles, I want all my ducks in a row before I tear into it, and my girlfriend's already unhappy that the car's out of commission (she doesn't want to drive the truck, the wimp)...

240 Ed · #15 01-06-2003, 04:53 AM

Oh, and a word about bushings...

I love urethane bushings. And I will gladly put up with the slight decrease in noise isolation for the increased feel in a car.

Having said that though, I think the Mercedes bushings are fine, and last a long time ( they lasted this long, right?). And the whole suspension has been tuned to these bushings.

Another point worth making; If you are going to repair the front end, it is wise to replace Everything at once to really benefit.