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  #76  
Old 08-10-2002, 03:09 PM
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Join Date: Nov 2001
Location: Miami, FL
Posts: 70
Problem solved?

Problem solved? Ok guys I have a question. They think they've found my shaking problem - improperly installed lower control arm bushing (1). A couple months ago I had the lower control arm bushings replaced due to shaking, steering, and ride problems. 90% of the problem went away with the new ones, but there was still a slight shake. After another mechanic looked at the car, he noticed that one of the bushings was installed 90 degrees off where it should be. Now, my NEW mechanic says yes, it is installed wrong and is probably the cuplrit. It hasn't cracked, but he says it's not bearing the loads like it should. He said you can't install them exactly centered most of the time, but they have to be within 10 degrees of spec or so, or else they are useless. My tranny, driveshaft and everything else about the suspension checks out. What do you guys think? Also this: my other C280 had to have new control arm bushings replaced at about 45k. This new mechanic says despite popular belief, this is one item on this car that goes out a lot earlier than planned. The same former mechanic that installed mine 90 degrees off, installed them BACKWARDS on my other C280 - it is now in the shop getting new ones installed. After only 4000k miles I have to put new tires on my other C280 - one side of each front tire is bare - I bought new tires for it 4 months ago. Great.

What do you think? Could this be the culprit?
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Mark E.
Miami, FL
2 X 1997 C280
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  #77  
Old 08-10-2002, 03:52 PM
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Absolutely!!!!!!!!!!!!!

I haven't mentioned this because 201/202/124 cars in general don't have control arm problems. BUT, they can be created.

If this is the case I can tell you about one similar just this week. Best of customers brings in her 91 420SEL to wait while we balance out a shake at 55. My best tech balanced and rotated the low mileage Michelins and didn't do squat to the problem. I drove the car and sure enough at times it would about take the steering wheel from ones hand. The vibration went away after 65mph. Sometimes if one was accelerating no vibration woud occur. Sometimes a small turn at speed would creat the vibration sometimes it would remove the vibration.

I placed the car on the lift and viewed the suspension. Everything was good including the rear suspension ball joint (front lower control arm rear ball joint/mount). This joint was not only good looking it was practically new. Knowing that we are the only people who have serviced this car for at least ten years, I know we must have put the mounts in. This doesn't stop me from condemning them and I remove the rear plates where the dampener rubber is held. I placed 2 large 3" diameter washers on each side between the mount and the dampener and bolted the acces plate back on. Now the problem was moved to 65mph and was much less apparent.

Now comes the story. I looked up the mounts in my EPC (electronic parst catalog) and got the number 126 330 11 xx (don't remember the last two digets. I placed that numeber in my dial system (a larger version of the Worldpac Dial system that is fastlane) and the number converts to 126 330 13 xx. Strange, so I called my MB dealer and asked for two 126 330 13 xx and they don't have any. Real strange (this is the best moving 126 front end part). I ask if he has the 126 330 11 xx and he doesn't have them either. I ask him to look them up again and he also gets the 126 330 11 xx (but doesn't have them - I guess they just don't work on 126 cars any more). He orders me two of each number so we can compare. They are almost identical with only a two diget number stamped into the metal back plate as the only difference.

Next I compared them to the Febi/bilstein ones that I had in stock. The rubber was obviously less than half as stiff as told by my durometer reading thumbs. I used the 126 330 11 xx mounts in the car and absolutely fixed the problem.

We fix this notorious shake in BMWs all the time by using stiffer compounds in the longitudinal strut rubber. Some times its a cut down bushing from a larger car (E32 750 bushings cut to fit in E34 5 series). Some times we use urethane bushings made in the after market. I have been experimenting with the urethane bushings on the same position on 140 chassis that have so much problem. It absolutely fixes the problem. The bushing doesn't hold up though and we are redesigning one right now using two small wheel bearings instead in an aluminum housing. haven't tried it yet.

The point to all this is, when it comes to anything using rubber structually, BUY IT FROM MB. The fact that I picked out this vibration problem quickly was the only gratifying part of doing the job over for free.

One more interesting part. Since both numbers were currently available, I asked what the 13 xx was for. He couldn't tell me. I looked it up in the EPC that I have and it showed that the 13 xx number was used in almost all 126 bodies - not intended for the USA. I am a little confused why the aftermarket mounts are sold under the euro number rather than the US number. I can tell you that the US number is more costly. It seems to be the stiffer one also.
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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician
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  #78  
Old 08-10-2002, 04:46 PM
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Very interesting Steve - I have a couple of questions for you....

Just a confirmation - can 1 control arm bushing installed off "center" cause all the shaking, and if so, how far rotated out of place would the bushing have to be? It doesn't have to crack or break to cause the problem, does it? I've seen what they look like and I guess I don't see were the load bearing part of the bushing is. It looks the same all around. As far as buying MB bushings, I'm guess that if I bought them off Fastlane that wouldn't be a good idea....

I tell you I'm going to puke if this truly is the problem. After all the time and $$$ spent.
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Mark E.
Miami, FL
2 X 1997 C280
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  #79  
Old 08-10-2002, 05:55 PM
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Among other things, the bushings are not symetrically designed. They are designed to take loading in specific directions. The ones I would worry about would be the rear bushing of the front lower control arm. When they are turned they face the load with the wrong support. This is a definite no-no.

Another problem faced by shops without frontend racks is that the bolts holding the center of the bushing to the frame should not be tightened while in the air hanging from a frame lift. They need to be tightened while sitting at curb height on a wheel type lift. By tightening with the wheels dangling the bushing is stretched more than its normal compression travel when sat back on the ground. This will destroy a bushing in no time and also change its strength in the appropriate direction.
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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician
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  #80  
Old 08-10-2002, 06:44 PM
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Well this makes sense to me now. This would also explain why my other c280's bushings and tires have been destroyed in less than 3-4 months. I know for a fact the shop I used didn't use MB bushings. I'm not sure where they came from - I asked if I would be getting MB parts, to which I was told there were products out there that were just as good and a lot cheaper. What a very expensive lesson for me to learn. But now I know. Incredible!

Thanks everyone.

CASE CLOSED
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Miami, FL
2 X 1997 C280
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  #81  
Old 08-10-2002, 06:59 PM
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Join Date: Jul 2001
Location: Old Lyme, Connecticut
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767 Flyer,

Glad to hear the ordeal is ending, and that you seem to have found a reliable shop to have the car attended to when it needs it. I am also glad to find out it was not a Mercedes-Benz defect in either design or manufacture. It actually sounds like you may have had something replaced that was ok to start with considering you only had 50,000 miles or so on the car.

One thing I did note in all of this is, when a real professional goes to work on a car and a problem results from that work, even possibly through no fault of his own, the pain is shared with the customer and the experience gets turned into another reason to return to that establishment. I am refering to the line from Steve which I quote "The fact that I picked out this vibration problem quickly was the only gratifying part of doing the job over for free. "

If you can find someone like that to work on your vehicle you will be miles ahead of the rest of the crowd looking for cheap labor. Congratulations Steve. If I lived in the vicinity I would use your shop!

Jim
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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)
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  #82  
Old 08-10-2002, 09:38 PM
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Location: Miami, FL
Posts: 70
Thanks Jim - Yup... I've been through 2 independent shops, and 2 dealerships. The ones that found the problem was a dealership. The problem was presented to me a while back, but I was told it woudn't make any difference in performance. I told the original shop about the misaligned bushing, they looked at it, said yeah it was rotated a little, what are you complaining about? Works fine! Oh well.... I'm glad a shop finally found the problem. I've been disallusioned with the dealerships down here in south Florida, and so went looking for an independent. I'm sure they are good, but for whatever reason they weren't with my cars. But all is good now.
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Mark E.
Miami, FL
2 X 1997 C280
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  #83  
Old 08-10-2002, 11:03 PM
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Join Date: Jan 2002
Location: Colorado Springs, CO
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This is really interesting discussion. I trust that my mechanic put the bushings in correctly, but he used control arm bushing kits from Rusty Cullens (that I supplied). There was a problem installing the passenger rear bushing, as the old one rusted in place and had to be cut out.

The symptoms that Steve described about acceleration, and a turn affecting it match my experience. I also notice it as soon as I pull my foot off the gas pedal, e.g. doing downhill. I notice it in the gas pedal, & steering wheel.

Since the bushings were installed, I've put about 48Kmi on the car.

What is the best way to verify the control arm bushings?

767Flyer, I hope your problem is solved!

Brian
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  #84  
Old 08-10-2002, 11:55 PM
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Join Date: Nov 2001
Location: Miami, FL
Posts: 70
Well, I hope so too. I will know in a few days. I noticed over 1600 views of my original post - all over a bushing! Gotta love this site!

Thanks everyone!
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Mark E.
Miami, FL
2 X 1997 C280

Last edited by 767Flyer; 08-11-2002 at 12:07 AM.
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  #85  
Old 08-12-2002, 09:18 PM
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Location: Colorado Springs, CO
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Steve,

I'm wondering about a few things with regard to these control arm bushings for my '87 300D. Today I asked the dealer shop foreman to check them out, and he said though they were installed incorrectly they were still tight, and should be Okay. The fronts are the ones installed incorrectly, backs are vertical according to the lugs. He seemed to think it could be a loose ball joint or tires/wheels. Does this sound right (are the rears more sensitive to being installed incorrectly?) Since the toe alignment has been set correctly tire wear is much better, but there is some sawtoothing on the outsides (much more minor than its been). I've been told by the alignment shop that some sawtoothing is allowed and it will show up more if I increased my city driving. Is this true? Thanks a lot for your expertice. I wish I lived near your shop, I feel my problems would have been long gone...

Brian
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  #86  
Old 08-12-2002, 10:07 PM
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Location: Gainesville FL
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"I've been told by the alignment shop that some sawtoothing is allowed and it will show up more if I increased my city driving. Is this true? "

Keep that alignment guy. Yes this is true. The more city driving the more effect. It has to do with the amount of caster in MBs. Great for handling, a compromise at slow speed. Sort of like a road grader as the wheels are turned the caster causes them to go positive caster on one side and negative on the other.
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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician
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  #87  
Old 08-13-2002, 10:33 AM
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Steve,

The shop I used does NOT have a front end lift. I asked one of the mechanics how they tighten the bushings, he said with the car in the air, he knew it wasn't the right way to do it, but doesn't have the correct equipment to do it another way.

Is it possible for the bushings to "feel tight" when tested, but improperly installed and tightened to affect the ride and cause vibrations?

If this is the case, I will take my car to the dealer and pay them to change out the bushings whether or not they feel its the thing to do. I can buy control arms w/ bushings & ball joints for $195/ea so I wonder if this would be easier than having them remove and reinstall these components....

Thanks,
Brian
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  #88  
Old 08-13-2002, 05:24 PM
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Join Date: Nov 2001
Location: Miami, FL
Posts: 70
Resolution

Well the shaking problem is solved. It in fact was just one front lower (rear) control arm bushing rotated 25% off where it should be. In just a few months it was showing wear, and the tech said it was about to crack. I looked at the thing and it was worn. Amazing. Well thanks everyone for your help. Who knew one part could cause all that trauma. And yes, what Steve B. said, go with MB parts with this stuff! It made all the difference.
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Mark E.
Miami, FL
2 X 1997 C280
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  #89  
Old 08-13-2002, 07:25 PM
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Great news

JOb well done,

Amazing how these guys can diagnos over the internet.

Joel
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  #90  
Old 08-22-2002, 01:55 PM
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Location: Colorado Springs, CO
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My control arms were replaced yesterday and the harsh vibration that would come and go appears to be gone There is still a smaller, more continous vibration, that I will treat separately...
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