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Hello All,
I'm looking to do a complete refresh of my rear suspension. Both rear airbags bleed down over the course of a few days if I don't drive it, the rear end gets a little swirly when I punch it even at highway speeds, every time I go over a speed bump at low speeds I hear a loud thud in the back. I would like to take everything out of the rear, all the down to the subframe/crossmember and start over. Before I take anything apart though, I want to make sure that I have all of the parts, tools, and torque specs that I need to complete the project without delay. I've seen a few posts in which members posted torque specs and video clips of one thing or another. I haven't been able to find a comprehensive video or thread, and I am also having an issue finding a shop manual for our cars. In any case, I've decided that I want to replace shocks and airbags, (I don't want to get rid of air suspension), and replace the bushings and bolts for the rear subframe at a minimum. I really want for the car to feel better than new. Several years ago, I owned a certain domestic car, and I installed tubular rear control arms on it. Made a huge difference and I would love to install something like that on my E55. I'm not looking to build a drag car, just looking to do a refresh. Does anyone have any recommendations on vendors that can provide a full rebuild kit? Or any threads on how to do it?
Pat
Hello All,
I'm looking to do a complete refresh of my rear suspension. Both rear airbags bleed down over the course of a few days if I don't drive it, the rear end gets a little swirly when I punch it even at highway speeds,
Pat
I also have what I would describe as a acceleration wobble out of the rear of my car (65K miles CLS55). When you punch it, sometimes I think its the tires just losing a bit of traction. However other times, merging onto a freeway for instance, the back end will get a pretty significant wobble. I don't have any clunk or anything else that would suggest parts are worn or falling off. I do have airmatic, but that shouldn't be causing this. I did pull a tire and inspect the rear suspension of the car, my assessment was it looks pretty damn clean.
I may mount a camera down there and see if it shows anything. I suspect that it wont take much and unless a part was falling off i may not see much.
Did you find a specific part that is worn that may be causing this? Not sure if I want to yank the entire rear of the car off just yet.
It is most likely your rear subframe bushings are worn out. I had this issue years ago, but covered under warranty.
The entire rear subframe had to come out, including exhaust, drive shaft and rear diff. And the bushings had to be pressed out and new ones pressed into the subframe.
Hence everything needed to come out in order to do that. This is no small job. If I remember correctly, it would have cost around $2100, mostly labor as the bushings and subframe bolts weren't expensive.
There are 5 arms in the rear suspension per side, 2 bushings each, 20 bushings total! Even at $25 a pop thats over $500 in bushings. A worn bushings in any of these arms would cause the rear end to behave funny. If I had to guess though #9/ #6 bushing might be a culprit of the rear end to wander under hard acceleration on/or uneven road surfaces but the rest could definitely contribute.
I would first check the subframe bushing bolts/mounting pins. The bolts have been known to break and some have even torn the mounting pins out of the body of the car.
If you are interested we just released our polyurethane subframe bushings that help stiffen up the back end of your car. Here is a video we made comparing good condition OEM rubber bushings vs our polyurethane bushings.
I certainly don't think that any parts are falling off, I may have exaggerated with the word "loud". It's "loud" to me, because I really don't like it whenever I hear it. Most drivers may not notice it though. Moving on, great suggestion with mounting camera's, I've got a couple of go-pro's and didn't even think about mounting them.
The first time that I noticed it, I put the pedal about 3/4 of the way down while doing 40, I was passing a dump-truck on a two lane back road, and I started getting the feeling that I was losing traction. But I didn't get the traction control warning lamp, didn't hear the tires, and there were no tire marks on the road. I'm definitely dreading the notion of taking the whole rear end out, but with all of the issues that other folks have had with the subframe bushings, I was kind of thinking that this might be a good time to start fresh. I'm happy that I am getting a lot of feedback on this thread.
I'm a firm believer in knowing what I'm doing before I jump in, so I appreciate the input. Driveshaft and exhaust aren't scary as long as I don't break an exhaust bolt. I'm a little more worried about getting all of the air/brake lines and cables and wires and sensors disconnected/reconnected. Also torque specs and best sequence for doing this job. I've searched the internet a little, without luck, for a shop manual for these cars. I've already decided that I will need to buy the special tool for removing bushings. Do I also need a STAR tool? This is starting to add up, not a huge deal. I've done a few clutch jobs, Subaru and Ford, and replaced a front subframe on a Mustang, so I'm not a novice, I know that I am also not a professional at this either.
This is certainly something to look into. Replacing a couple of bushings on a couple of control arms looks like a simple task compared to what I am preparing myself to do. Maybe I can get my go-pro on these little guys and save myself a lot of time and money.
No need to pull the whole subframe out of the car. Put your go pro under there and see what is moving. If it is control arm bushings just take the arm off and replace the bushing on the bench. If it is subframe bushings, we have a tool that we rent out with detailed instructions on how to replace them with the subframe in the car.
No need to pull the whole subframe out of the car. Put your go pro under there and see what is moving. If it is control arm bushings just take the arm off and replace the bushing on the bench. If it is subframe bushings, we have a tool that we rent out with detailed instructions on how to replace them with the subframe in the car.
This is good information. I will likely go this route if the subframe bushings are indeed the problem. I read one thread where someone spent a lot of time forcing his bushings out with some tools that he had in his garage. My goal is to eliminate as many frustrations as possible before I get started.
I’m in the process of having this refresh done as well.
The mechanic was in the midst of lowering the subframe for the rear upper control arms and rear bags. He noticed the subframe bushings were dead and ordered the parts from Germany. In the meantime it was buttoned up, and returned. It’s back in there now for the parts replacement.
You may ask why the subframe had to be lowered for the upper arms. Well, from the factory the control arm bolts were put in backwards in such a way they could not be removed without the frame being lowered....
If if you think it may be an arm, or whatever, just make sure you look at bolt orientation to make sure you don’t have to drop the frame a little anyway creating the perfect opportunity for the subframe bushing replacement or other.
The cost of this is unknown at this point. I also had brakes installed, front sway, upper and lower coolant (radiator) hose. Parts came from fcp for the brakes, can’t remember on the arms, rock auto on rear bags.
I am very fortunate to have a friendly honest mechanic that is a driving instructor enthusiast for his whole life. I usually have to offer him more money or sneak a tip cause I know it might be unaffordable otherwise. I do a lot of my own work but not when it’s cold and rainy. I work on his schedule and have another primary driver so this might sit for a week.
So make sure to check those bolts and always have a friendly mechanic on call👍
"You may ask why the subframe had to be lowered for the upper arms. Well, from the factory the control arm bolts were put in backwards in such a way they could not be removed without the frame being lowered...."
So the control arm you are talking about is part #8 in the diagram above? Are the bolts always in backwards or was this an anomaly?
thanks
There are 5 arms in the rear suspension per side, 2 bushings each, 20 bushings total! Even at $25 a pop thats over $500 in bushings. A worn bushings in any of these arms would cause the rear end to behave funny. If I had to guess though #9/ #6 bushing might be a culprit of the rear end to wander under hard acceleration on/or uneven road surfaces but the rest could definitely contribute.
What is the part # for #6?
I'm going to get a rear linkage rebuild kit that includes all control arms and sway bar end links just doesnt hat bushing in the spindle, so I will have to buy that separate. On part #14 (main control arm arm) is it worth getting the bushing that appears to be pressed into the subframe done while doing the rest?
I'm going to get a rear linkage rebuild kit that includes all control arms and sway bar end links just doesnt hat bushing in the spindle, so I will have to buy that separate. On part #14 (main control arm arm) is it worth getting the bushing that appears to be pressed into the subframe done while doing the rest?
Part number 6 is a bushing that is pressed into the knuckle. I would definitely replace part number 14 as it is your rear lower control arm bushing. This bushing is one of the most important in keeping everything from moving (although it doesnt do the best job).
Hello all,
I finally decided to make videos of two left side bushings. The first video will be of the rear subframe forward bushing and the second video is of bushing #9. I tried to crop a video of a side by side but I don't have the software. Please fast forward to about 1 minute.
Patrick
Hello all,
I finally decided to make videos of two left side bushings. The first video will be of the rear subframe forward bushing and the second video is of bushing #9. I tried to crop a video of a side by side but I don't have the software. Please fast forward to about 1 minute.
Patrick
Sorry about that. Apparently mp4's aren't supported or my computer isn't acting right, so I had to upload to youtube. Here is the link for the subframe bushing.
02-23-2019, 08:14 PM
Time to get the camera out, maybe I can isolate it, if not maybe just get some cool video.
