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What is that GRINDING NOISE? Brakes or wheel bearing?

7K views 28 replies 7 participants last post by  petesmga 
#1 · (Edited)
This is a double post because I'm looking for help and the subject in the other thread didn't match my current need.

I turn left, and I hear a grinding noise. I'm feeling pretty confident it is either the front right wheel bearing (which I just replaced due to the noise), or the front right rotor.

More description at: http://www.benzworld.org/forums/r-c...ory-vapor-lock-again-today-3.html#post4636981

Any help or ideas will be greatly appreciated. THANK YOU!

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EDIT: To save you from reading the whole thread
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Problem solved. It was the fan shroud. Motor moving more now I guess with the new, non-crushed motor mounts and subframe bushings. My car was also in an accident and the radiator isn't lined up correctly. So the fan shroud isn't centered on the motor (at least not now). So when I banked a hard left, the motor moved far enough to the right for the fan to hit the shroud. Who knew?
 
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#2 ·
In your description you mention replacing the bearing on the right side, There is an inner and outer, one easy one not so easy. You did replace both, didn't you??????????????
 
#3 ·
Yes. Thanks for clarifying. The only parts I did not replace were the wedge shaped parts that sit inside the wheel hub. These came with the new bearings, but the old ones looked OK. I also had no idea how to extract the old ones (the wedge shaped rings) from the hubs.

I did also replace the grease seals which sit behind the inner bearing.

I also did my best to follow the instructions in the CD manual file 33-300.pdf but I just don't have all those specialty tools. I guess I could have tightened the bearings to much and wrecked 'em.
 
#4 · (Edited)
OOPS--- DOUBLE POST--- Darned Blackberry made it look like previous post failed. Sorry.
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Yes. Thanks for clarifying. The only parts that came with the wheel bearing kits that I didn't use were the rings that sit in the wheel hub (both inner and outer) because I wasn't sure how to get them out. I followed 33-300.pdf from the CD manual as best as possible, but don't have the specialty tools.

I'm wondering if the bearings are too tight, and maybe I even wreck 'em.
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#5 ·
The wedge things are the bearing races, and they are usually repaced with the bearing. Did you look at the races, and if so did they look ok, no pitting or bluing of the surface???
As far as overtightening the bearings, I don't think you could do that unintentionally. Normally you would pack the bearings, install them, tighten down the nut while rotating the hub, this allows for the bearings to be fully seated, when the hub becomes difficult to rotate by hand, stop, and back off the nut a little, maybe a quarter turn. this should allow the hup to be rotated easily, this is not the manual proceedures, but will be close in my opinion.

Have you rotated the hub with the wheel off to see if the rotar is warped from the heat??? If it was glowing red, it should be replaced....
 
#6 ·
Definitely no pitting on the bearing races. I'd have to open them back up to look for blue.

The rotor isn't warped (at least not in the typical sense). The brakes had been fine in the period of time between rebuilding the caliper. I drove the car like a bat out of hell until coolant started dripping on my foot. The shop did the whole front end, but didn't get to: bearings, coolant leak, rear shocks. I saw they were leaving the car out in the rain, so I drove it home. I waited for them to finish the work for months and recently gave up on them.

It sounds like I tightened the bearings properly based on your procedure.

Since this all started after the front end was rebuilt, maybe there's something grinding or rubbing that I just haven't found yet. I need to have someone else drive while I watch from the ground or something.

I'm stumped.
 
#7 ·
Tell me you have a manual.

And if you do....the procedure to replace the race is in there.
Diagnosing a grinding noise over the internet is like......



Hey Mike! What's that smell? Do you smell it? Someone in my neighborhood is cooking! But what is it??
 
#8 ·
If it's a rotational grinding noise then it narrows your search down to things that rotate.

Sound travels on a chassis so don't be fooled.

Turn left, turn right, brakes on, brakes off, go fast, go slow, trani in drive, coast in neutral, go in reverse, car hot, car cold, etc.

Get a helper.

Look under the car around your prop shaft, parking brake cables, rear rotors , brake dust shields, etc.
 
#11 ·
I assume BFH is a big hammer, but it was interesting to read other possibilities: Urban Dictionary: BFH

I haven't searched for the manual PDF yet, but I assume it would require a hammer and the right sized pipes, two different sizes for the two different races. When I realized that, I removed the old grease and ran my finger over the old races. I thought they looked fine. In fact, the only parts that looked damaged to me were the black grease and the inner grease seal.

Everyone says they think it's coming from the front right wheel, but I have to agree with some rear axle possibilities. Nothing on the rear axle has been touched, but the emergency brake cable has had a lot of use recently. (But of course, the e-brake was unlikely used at the shop where the problem was produced... because they have a real lift, unlike me who keeps just jacking the front end.) So I still have to say I'm confident this is coming from the front end.

I think my next step is laying on the ground while someone else drives the car for me. I can consistently reproduce the grind turning left after backing out of my driveway. So I'm hoping to lay in my driveway while someone else pulls away ... maybe with the car forever. :)
 
#16 ·
Still did the grind in Neutral.

I couldn't assure the noise was coming from the passenger side, but it was clear that when the car tilted to the right from a left turn the scrape occurred. I opened the hood to check the fluids and assure I wasn't hearing the sound of a pump scraping for fluids that were empty. Fluids looked OK. BUT... there was a strange thing that looked kind of like a rough black sponge sticking out of my fan shroud. Wait.. That's the fan shroud itself shredding!

My "reconstructed" car has the radiator far enough out of line (too far to the driver side) that the motor with the new motor mounts, now will hit the passenger side of the fan shroud on a left turn. AIN'T THAT A B.

So I'm diagnosed, but not yet "fixed".

FAN SHROUD.
 
#20 ·
Guys. Thank you all SO much for the help with this wheel bearing lesson. I assume you guys figured out by now that I only replaced the "cone" including the inner race, and left the old outer race. I knew this didn't look right, but I was scrambling to get to the bottom of the root of my scraping sound. Since the old wheel bearings looked fine, and I still have them, maybe when I re-install my dust shields I should just put the old wheel bearings back. That certainly would be the easiest thing to do for a match set. However, I know that the one bearing certainly has some wear on it after the "night of the glowing rotor". Additionally, I'll need to keep the new inner seals (as opposed to reverting to the old ones). The one inner seal look cooked. If there's any reason that inner seals need to be matched to the bearing, then there's no going back to the old bearings, and the out races must be removed. It certainly sounds like the right thing is to take the wheel hubs in to have a shop removed the old outer races. This is information I couldn't have known without you guys. THANK YOU!!!!

I need to take the car into the shop to have the new motor mounts checked anyway. It seems like the motor is moving too much, too easily. Even a slight turn was enough to move the fan a centimeter to the right. Is that normal for a car with new motor mounts and subframe bushings? Is it possible that it was all put together too loosely?

THANKS!

I'm so glad to be able to drive the car without creating all kinds of loud noises! I can't wait for a reason to drive 10-20 miles!
 
#22 ·
Sorry! :-o

I sure as heck learned a lot about wheel bearings though!

How the heck was I supposed to figure out that the engine would rock so much to the side of the car while turning that it would do that? The grind got louder in harder turns. Everyone kept telling me they also thought it was coming from the front passenger wheel. I clearly fed the fire though.

I never thought to look under the hood too much when I'd been told my wheel bearings need replacement (just because they were loose).

Can't you see I should not be working on my own car?

On the other hand, can you see how much I've learned about this car in the last 8 months? I didn't know ANYTHING when I bought this car. So let's look at the bright side, and see everything I've learned:
- Vapor lock
- brake hoses
- wheel bearings
- rear sway bar links
- fuel pump diagnostics and fuel pump relays
- injector diagnostics
- leaking fuel lines
- coolant lines leaking in the heater box

Sure it doesn't look like very much to anybody who knows their @$$ from a hole in the ground. However, for me, I feel like I've learned a TON, and having fun too... thanks to you guys here.

So THANK YOU!
 
#24 ·
Oh yeah. I think Nobby is just embarrassed for me, not breaking 'em. I should have inserted a few smiley faces to help with the tone. I do feel bad to have wasted folks time, but as you can see, this turned out to be a decent thread on wheel bearings. I don't believe there's a thread with this much wheel bearing detail (until now), at least not with "wheel bearing" in the subject/title. So no time was truly "wasted".

And I have to say that I'm very happy right now! I've finally fixed that damned grinding that was keeping me from driving my car! FINALLY! :)

And Pete, you remind me...
- AC Recharging. Try Freeze-12 first. Right? It's getting warmer so I'll be ordering my kit soon! Got my fingers crossed for it to work!
 
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