Rear wheel bearings and automatic trunk opener
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1986 560 SEC
Rear wheel bearings and automatic trunk opener
Hey All;
I have a 2004 CL 500 and I have two issues Im dealing with. 1st is I need to replace my right rear wheel bearing. I initially thought it was my center bearing. I had that replaced along with both flex discs, but unfortunately, that wasn't the problem. It seems to be my right rear wheel bearing. The rear isnt leaking, and fluid looks good, and up to proper level. The bearing noise I measured at 82 DB in the cabin, so its getting really bad. The noise starts around 15-20 MPH, and increases with speed. So, now I need to replace the rear wheel bearing. I cant seem to find any good tutorials on this, so any help is appreciated.
Second issue is with my automatic trunk opener. It worked fine when I took it to the mechanic that did the center bearing. The battery died when that car was sitting, so he had to manually open the trunk, and somehow in doing so, the opener no longer works. When I use the key, or the release in the cabin, I can hear the motor operating, but the trunk deck will not lift. Any thoughts on this are appreciated too.
Thanks
I have a 2004 CL 500 and I have two issues Im dealing with. 1st is I need to replace my right rear wheel bearing. I initially thought it was my center bearing. I had that replaced along with both flex discs, but unfortunately, that wasn't the problem. It seems to be my right rear wheel bearing. The rear isnt leaking, and fluid looks good, and up to proper level. The bearing noise I measured at 82 DB in the cabin, so its getting really bad. The noise starts around 15-20 MPH, and increases with speed. So, now I need to replace the rear wheel bearing. I cant seem to find any good tutorials on this, so any help is appreciated.
Second issue is with my automatic trunk opener. It worked fine when I took it to the mechanic that did the center bearing. The battery died when that car was sitting, so he had to manually open the trunk, and somehow in doing so, the opener no longer works. When I use the key, or the release in the cabin, I can hear the motor operating, but the trunk deck will not lift. Any thoughts on this are appreciated too.
Thanks
Junior Member
Joined: Feb 2018
Posts: 60
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From: San Francisco
2001 CL500 AMG Sport
I just replaced my rear right wheel bearing on my 01 cl500. It was screaming loud when going 30mph or faster. It actually got so bad that it made a crazy loud rattle noise that i thought was the catalytic converters. Spent 50 bucks on ebay for new rear wheel bearings and did the work myself. All quiet now and runs great. To get to the wheel bearings you have to remove the brake caliper and rotor. Then remove the rear axle. Make sure to mark which way the axle was bolted to the rear diff so it can go back exactly the same way. I just used chalk to mark the axle for reference. After that remove the wheel hub (this will most likely be stuck due to age and possible surface rust.) So be ready to fight that thing off haha. Once you get the hub off you can see the wheel bearing. There is a big C-clamp that locks the bearing into place. Not easy to get off without the right tool. I used a bearing puller on the assembly so that i could remove the bearing without having to remove the entire assembly from the car. Didnt want to deal with all the rear bushings and bolts and possibly needing alignment after the job. Saved alot of time. Installation is opposite of removal. Just use a little bit of WD40 for lubrication on the new bearing. Good luck!
A bit of advice,
Sometimes when you remove the hub it will actually rip half the bearing off with it. If that happens you will need to remove it from the hub before installing the new bearing. This happened to me. I ended up having to use my buddies press after all to mount scissor jacks and press the old half of the bearing off the hub. If you think this out out of your wheelhouse then definitely take it to a independent shop and have it done.
A bit of advice,
Sometimes when you remove the hub it will actually rip half the bearing off with it. If that happens you will need to remove it from the hub before installing the new bearing. This happened to me. I ended up having to use my buddies press after all to mount scissor jacks and press the old half of the bearing off the hub. If you think this out out of your wheelhouse then definitely take it to a independent shop and have it done.
Last edited by Maclogos; Mar 28, 2018 at 06:34 PM.
Thread Starter
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1986 560 SEC
Thanks for the info. But my output shaft from the differential doesn't have bolts as I thought it would, or am I missing something? There seems to be a rubber boot, does the boot need to be pulled back to expose the bolts that hold the output shaft onto the differential? That was the only part I'm a little confused with. Also, do I need to remove the parking brake if I'm not removing the whole hub assembly? And I've seen in some videos that the outer bearing race will be stuck to the outer part of the hub. I was pretty much anticipating that too. Also, while Im at this, Im going to replace the upper suspension link which seems pretty worn out.
Thanks for your help!
Thanks for your help!
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Joined: May 2015
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From: Miami, FL
2003 CL 600
When I did my right rear wheel bearing on my 600, I pulled the entire hub and did it in the press. Not the worst job, lots of links and bushings but everything comes out logically. Do be sure to raise the wheel back up to driving position with a jack or something before tightening down bushings, so they aren't preloaded.
The trunk opener, it sits under the battery, it's possible something got damaged/moved, but they are usually leaky at this age. Check if it has fluid in it, mine leaks and needs to be rebuilt. Tophydraulicsinc.com rebuilds the pump or ram or both for a reasonable price, the part is only available as a complete unit from MB and is about $1000 last I checked.
The trunk opener, it sits under the battery, it's possible something got damaged/moved, but they are usually leaky at this age. Check if it has fluid in it, mine leaks and needs to be rebuilt. Tophydraulicsinc.com rebuilds the pump or ram or both for a reasonable price, the part is only available as a complete unit from MB and is about $1000 last I checked.
Thread Starter
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1986 560 SEC
Any idea what size the center hub nut is? I bought a 30MM socket, and it was too small, then I bought a 32MM socket, still too small??
Last edited by kenhartz; Apr 1, 2018 at 01:38 AM. Reason: Typo
MBWorld Fanatic!
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From: Miami, FL
2003 CL 600
Don't remember, and I don't have my car here at the shop with me today to check. If it's bigger than 32mm it's probably a 36mm, that's usually the next step up and they are large axles.
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1986 560 SEC
Turns out, the rear axel nut socket needed was a 32mm 12 point. Got the nut off easy enough, but my output shafts don’t have nuts attaching them to the differential. I would have to open the differential and release a circlip to allow the shaft to be removed. Plus, to get the shaft out of the way, I would have to take off quite a few of the suspension links, so, I’m going to just take the whole hub off, and attempt to leave the output shaft in. Then I’ll press out the bearing as my friend has a hydraulic press. Or, I’ll just take to a machine shop to press out, and press in the new one. Plus, my upper suspension link is really shot, so that’s getting replaced too. I knew something was worn, as going around a corner I would feel abrupt lateral movement, like the sensation of the car being blown from the side by a strong wind.
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MBWorld Fanatic!
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From: Miami, FL
2003 CL 600
If there's nothing exposed on the axle, it should just pull out of the diff. You don't have to open it to release it.
I pulled the knuckle off when I did mine anyway. Gotta be able to press the bearing out, and on the car is messy without the right tools.
Check your rear upper strut mounts, they fail often and create a similar looseness in the rear feeling over small bumps, most noticeable when turning.
I pulled the knuckle off when I did mine anyway. Gotta be able to press the bearing out, and on the car is messy without the right tools.
Check your rear upper strut mounts, they fail often and create a similar looseness in the rear feeling over small bumps, most noticeable when turning.
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Thread Starter
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1986 560 SEC
Bearing update, job completed, and I ended up pulling the whole hub off, and took to a machine shop to press the bearing hub in and out. Also, the top camber link was REALLY shot! Bad news is, noise is still there. I’m gonna do the other side , but I’m getting concerned that it’s an output shaft, as the noise doesn’t diminish when I turn the car to load the bearing on the left side. The noise is still more prominent on the right side when I turn the car to load that side. Also, the car will shudder when I accelerate when rolling. From a dead stop, I don’t notice it. I’m still holding out hope that doing the other bearing, and upper camber arm solve my problem. I’ll hopefully report success!
Thread Starter
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1986 560 SEC
those were replaced along with both fire and aft flex discs. I was sure that the center bearing was the culprit, but unfortunately not. , and neither is my right wheel bearing. Now, I’m gonna do the left side. If that doesn’t work, I’ll cry myself to sleep for a few nights, then attempt either output shafts?? Or a bearing in the differential?? But I’m hoping it’s the left side. These bearing noises radiate and it’s really hard to pinpoint while driving sometimes.
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2002 CL500 to CL55 conversion
i'm having issues with my wheel speed sensors, i get code p0500 and lately i've had a bit of a grinding (metal on metal) noise from my rear driver side wheel that i assumed was just related to old brakes. now i'm starting to question the bearings/axles. i get constant ABS lights, with ESP errors, brake lifespan errors, and stiff power steering all of the sudden since my control arm jobs. i took all the necessary precautions in safeguarding the front wheel sensors, they were not damaged at all in my control arm job so this has all been sort of strange. really hoping it's not a front SAM problem
i replaced my front control arms and i think in the process of raising and lowering the car i've messed up the rear wheel speed sensor? i replaced the driver side front speed sensor, from my research it seems p0500 refers to an error on the driver side, front or rear. it's that or i need a new axle because i think the tone ring on the rear is part of the axle. if anyone has any extra info feel free to provide. i only spent $20 on a used wheel speed sensor for the front, but i'd prefer to avoid throwing money at the problem unless iknow it will work
note - i also get a bit of vibration in the rear at higher speeds (60-80 mph) that i've always thought was the tires/rims. i've replaced the flex discs already in the past so they should be good
i replaced my front control arms and i think in the process of raising and lowering the car i've messed up the rear wheel speed sensor? i replaced the driver side front speed sensor, from my research it seems p0500 refers to an error on the driver side, front or rear. it's that or i need a new axle because i think the tone ring on the rear is part of the axle. if anyone has any extra info feel free to provide. i only spent $20 on a used wheel speed sensor for the front, but i'd prefer to avoid throwing money at the problem unless iknow it will work
note - i also get a bit of vibration in the rear at higher speeds (60-80 mph) that i've always thought was the tires/rims. i've replaced the flex discs already in the past so they should be good
