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Discussion Starter #1
I had these on my car for 3 weeks until I swaped them out for TC Kline spherical bearings and mounts. They look brand new. New they cost $99 so I'm looking for $60. This is an important mod if you run aftermarket shocks because the stock mounts flex and break.
 

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pmpn8ez said:
This is an important mod if you run aftermarket shocks because the stock mounts flex and break.
Can you go into more details on how it could break and/or provide link(s)? I've never heard of this. I'm bout to install the Bilstein coilovers. Do I need front mounts as well? Also, why did you get the TC Kline parts instead? Much appreciated & thanks!
 

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Re: Re: FS Ground Control Rear Shock Mounts

Yup Yup! said:


Can you go into more details on how it could break and/or provide link(s)? I've never heard of this. I'm bout to install the Bilstein coilovers. Do I need front mounts as well? Also, why did you get the TC Kline parts instead? Much appreciated & thanks!
no only rear shock mounts are necessary. since you are running much stiffer suspension, you may break the stock ones from the added stress/aggressive driving. even getting the e46 m3 rsms would be sufficient.

go to http://www.uucmotorwerks.com/ and click on Tech Tips on the bottom then rear shock mounts. it will give you all the information you need and they are OEM parts
 

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Discussion Starter #7
I switched to a TC Kline RSM because they use spherical bearings instead of a bushing. When you lower your car (and in an e46 you should lower the rear as low as you can because the rear roll center is very high) the angle and movement of the shock will change. Shocks are only designed to move on a straight up/straight down axis. By changing the lower mount position outward on a lowered car you introduce a lateral or side force on to the shock as your suspension moves up and down. Shocks don't like lateral force because it causes binding and premature wear on the seals. Many of the lowered e46s I see have leaking seals in the rear for this reason. When you're installing your coilovers you'll notice that you actually have to force the shock into position at the trailing arm to get it in position to bolt on. This is because the bushing is trying to keep the shock on its original axis that it enjoyed before you installed new springs.

By using a bearing, the shock will always move on its natural axis regardless of the attach position. The drawback is ride quality. BMW uses bushings to help buffer little bumps that are felt through the suspension. The bearings acts as conductors and let those vibrations through. All race cars use bearings. I have replaced the factory bushings with bearings in the rear Trailing Arm, rear Lower Control Arm, rear Upper Control Arm, and rear Shock Mounts and the suspension is incredibly smooth and active with absolutely no binding. For most people, however, the installation work that is required combined with the increased road feel is not worth the upgrade.

In the e36 M3 the lower control arm came with bearings and the upper control arm came with bushings. It was a common upgrade to order a second pair of factory lower bearings and install them in the upper position.
 

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Re: Re: Re: FS Ground Control Rear Shock Mounts

Ci FLY said:
you may break the stock ones from the added stress/aggressive driving. even getting the e46 m3 rsms would be sufficient.
I just read your post & also read the RSM tech tips on UUC's website. So let me get this straight...Since I already have an 03' e46 M3 coupe, I won't need to buy the rear shock mounts UUC & yourself are talking about right? Sorry, I just want to make sure. Thanks!

pmpn8ez, thanks for info also.

What would all of you recommend I do if I want the most comfy ride w/the Bilsteins?...

1) Retain the oem M3 rear shock mounts or

2) Get the rsm from JT Designs: http://store.yahoo.com/jtdesigns/rearshocmoun.html
 

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Discussion Starter #9
The standard M RSMs do flex. They are not great but they work. You probably will not need to upgrade them with Pss9. The only argument to do it would be that they only cost $99 from TC Kline or Ground Control and while you have the shock out it is an easy upgrade.
 

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The reason most people go with the M3/Z3 RSM combo is because it is cheaper but for ~$60 you might as well get the GC ones. I have them on my ride with the PSS9's and they are great. The ride is not too harsh. If you do a search on RSM's you will see alot of threads that mention why you should upgrade. It's a cheap mod and it also reduces the chances of having major Rear shock tower problems.
 

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Does your GC rsm's make any noises b/c I've heard it does? Also, when you say, "major Rear shock tower problems", are you referring to the oem rsm's possibly cracking??? Thanks!
 

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so we wouldnt need them if we just changed our springs and not our shocks?
 

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Actually there have been some people who had some problems that might of been due to not changing the RSM's. From what I understood from some of the posts, the stock RSM's were not strong enough to withstand the extra impact due to fact that the shock's now have less travel distance because the car is lower and this results in more impact on the rear shock tower. I believe teh GC (or similar) RSM's help absorb or distribute the impact better then the stock ones. Either way the extra money spent on the RMS's compared to what you would have to pay if something were to happen is very minimal. It's just a safer way to go. Maybe someone should send out an email to GC to get a more detailed answer.

Yeah and with my GC's there is not increase in noise at all. At least not one that I notice.

egyptnads said:
so we wouldnt need them if we just changed our springs and not our shocks?
 
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