M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Suspension => Topic started by: mikesjo on August 08, 2006, 02:07:53 AM

Title: E46 Shock mounts suck!
Post by: mikesjo on August 08, 2006, 02:07:53 AM
Yeah don't use them.

Drove around today and went over a sewer and BOOM the stupid bushing in the damn shock mount went right through the thing. The carpet in the trunk and the spring stopped the whole shock from going any higher is what I'm guessing. So now the car is in my driveway with no shock in the rear driver side.

Going to see if BMA will cover the part, then I have to find some better RSM. Probably IE or GC.
Title: E46 Shock mounts suck!
Post by: tim_s on August 08, 2006, 02:14:04 AM
Yup, I've had this too. Wasn't doing anything out of the ordinary, but the bushing popped out through the surround. I use koni adjustables on medium hardness. I have e46 m3 ones in there now that have been in there for a yr or two which have been fine, however.
Title: E46 Shock mounts suck!
Post by: mikesjo on August 08, 2006, 03:13:52 AM
What's the difference between the E46 and E46 m3 ones?
Title: E46 Shock mounts suck!
Post by: M42boy on August 08, 2006, 10:18:50 AM
Sounds like a defective part.  I can't imagine even OEM E30 shock mount blowing out like that in that short of time.  I think if you get BMA to send you a replacement, you will be fine.  

I can reccomend the Turner Motorsports aluminum high-strength rear shock mounts.  Seem to work fine on my car.  See link below.  

http://www.turnermotorsport.com/html/detail.asp?PRODUCT_ID=JTD909

That being said, I'm a bit supprised you had any problems.  BTW, I've heard the E46 Cabrio RSM's were the way to go.  I think they are a decent bit stiffer than the regular E46 mounts.
Title: E46 Shock mounts suck!
Post by: Febi Guibo on August 08, 2006, 10:23:30 AM
I used IE E30 rear mounts, but a quick question: did you have a washer above and below the shock mount? just curious...
Title: E46 Shock mounts suck!
Post by: Eurospec on August 08, 2006, 01:28:03 PM
Ditto, 2 washers per rsm.

My JTD mounts purchased from BMA are holding up just fine.
Title: E46 Shock mounts suck!
Post by: mikesjo on August 08, 2006, 02:09:56 PM
I had a big washer on top before the nut goes on, none below. Anyone have a pic of the one below? On Pelican's site it doesn't say you need a washer on the bottom of the RSM, just the top.

I'm ordering IE ones right now from BMA.
Title: E46 Shock mounts suck!
Post by: Febi Guibo on August 08, 2006, 02:23:47 PM
yeah, in general, you need washers above and below
Title: E46 Shock mounts suck!
Post by: mikesjo on August 08, 2006, 02:50:56 PM
How would the washers below the RSM stay in place? Pics!
Title: E46 Shock mounts suck!
Post by: Febi Guibo on August 08, 2006, 03:34:53 PM
locknut - washer - shock mount - washer
(or something like that)

there are pics at zoso's website, except that his server is not responding right now --mike, put another quarter in the machine!!
Title: E46 Shock mounts suck!
Post by: 2002maniac on August 08, 2006, 05:22:04 PM
I have thr E46 M3 vert bushings and they are showing wear after a year of use.
Title: E46 Shock mounts suck!
Post by: mikesjo on August 08, 2006, 05:37:45 PM
How does the washer stay in place if it's under the RSM though? Do you still put a washer under there if you're using say an IE or GC RSM?
Title: E46 Shock mounts suck!
Post by: tim_s on August 09, 2006, 03:30:00 AM
mine had the washers in place above and below, was assembled exactly as per the ETK. Still popped an E46 rubber out of its surround, the part was only 6 months or so old. I run koni adjustables, eibach arbs etc.
believe the rubber insert is stiffer on the E46 m3/cab part, they have a different part no. from standard E46 ones. i wondered whether the problem lay in the fact that I was running the E46 top mount with the rest of the E30 assembly. maybe changing the rest of the assembly to E46 stuff would help.  ive not had any trouble since with the E46 m3 stuff, but im guessing that running uprated suspension means you are more liable to pop rear shock mounts.
Title: E46 Shock mounts suck!
Post by: mikesjo on August 09, 2006, 04:36:47 AM
Do i still need the washer on the bottom w/ IE or GC ones?
Title: E46 Shock mounts suck!
Post by: M42boy on August 09, 2006, 08:21:08 AM
Quote from: mikesjo
How does the washer stay in place if it's under the RSM though? Do you still put a washer under there if you're using say an IE or GC RSM?

Mike, the nice thing about the Turner RSM's is that they have replaceable rubber bushings in the center.  The mount never goes bad, and you can buy replacement bushings from Turner for $15 a pair from Turner.  

This sounded like a winner to me.

Febi...   I'm concerned as I dont' have a washer on the top of mine either!  I was really confused as I would have figured Turner would have included washers if I needed them, but when tightening the top nuts, it didn't seem right to not have one.  

Do you use the factory washer (which looks concave in the Real OEM pic) or can I use any old decent sized washer from the hardware store?

Can someone post pics for mikesjo and I?  I'd like to see what others are doing.  I can understand having one on the top, but a little confused as to why you'd need one below.
Title: E46 Shock mounts suck!
Post by: M3kos on August 10, 2006, 09:24:42 PM
i had exactly the same thing happen to me, and these were boge e36m3 top mounts, part number is 3352 1092 362

big nasty pot hole did it to me

looking at the damaged one it could be a faulty part, as its split all the way through, but bush is intact if you follow !?!?

alloy and polly ones may be the way to go i think
Title: E46 Shock mounts suck!
Post by: bmwman91 on August 10, 2006, 10:44:58 PM
Get the GC ones.  I have thrashed the hell out of them for almost 3 years now, on both of my cars.  Best $80 I ever gave to http://www.bimmerworld.com !
Title: E46 Shock mounts suck!
Post by: Zoso on August 11, 2006, 07:15:45 AM
Quote from: Febi Guibo
locknut - washer - shock mount - washer
(or something like that)

there are pics at zoso's website, except that his server is not responding right now --mike, put another quarter in the machine!!


I don't have a great shot of the E46 rear shock mounts... the suspension install was nearing completion (had already finished the fronts).  The beers started catching up to my friend and I... so I forgot to take pictures of everything.

(http://zoso.no-ip.org/images/318i-rearsuspension/01-rear.jpg)
(http://zoso.no-ip.org/images/318i-rearsuspension/09-newrsm.jpg)



Quarter inserted.  :)

The benefit of my web server is that it has basically unlimited space and is free since it's in my house.

The downside is that my cable modem's uplink speed sucks.  My wireless internet gateway/router also sucks.  If turn on a bit torrent, the router can't keep up with all the IP level connections.  The first thing it drops is DNS requests, incoming web requests, and the wireless network connections (my wife HATES that).  After that it totally pukes and I can't even surf the web.


Back to the original topic:
The E46 RSM are the best ones BMW has made so far.  Make sure you also get the Z3 reinforcer plate for the RSMs.  From what I've read, they really help.  There are aftermarket solid ones and ones made of urethane, but they do nothing to absorb noise, vibrations, or harmonics.  I don't want my BMW feeling like a tank... I want some comfort.  I think the E46 RSMs with with Z3 reinforcer plates are a great compromise.

One more thing:
For a long time, I thought my E46 RSMs sucked because I heard a lot of clunking back there over bumps.  It turned out that the clunking was actually the muffler bouncing around due to loose hanger bushings.
Title: E46 Shock mounts suck!
Post by: mikesjo on August 11, 2006, 11:30:35 PM
I don't see the bottom washer in that shot ><. Your reinforcement plate, isn't it on top of your shock tower inside the trunk not from underneath the shock tower like it looks the way you have it preassembled?
Title: E46 Shock mounts suck!
Post by: e9nine on August 12, 2006, 12:19:14 AM
Quote from: Zoso
......
The E46 RSM are the best ones BMW has made so far.  Make sure you also get the Z3 reinforcer plate for the RSMs.  .......I think the E46 RSMs with with Z3 reinforcer plates are a great compromise.

That's all I have to agree to. I have used them with 475/800/650 rear spring rates to date with no issues *(KNOCKING, POUNDING, FISTING the computer desk now)* to date. Dunno what it is that's causing failure prematurely :confused:
Title: E46 Shock mounts suck!
Post by: mikesjo on August 29, 2006, 04:22:51 AM
Well I reinstalled the IE RSM on my drivers side and everything is working well :). I'm really impressed as to the build quality of the IE RSM. I notice it being a bit bumpier back there now with the urethane mount. I put the stock washer on the bottom of the mount this time and I have another one on top. I doubt these will pop out though because the center of the IE RSM has a smaller diameter circle of aluminum and the urethane is split in two halves, top and bottom. I'll have to do the other side when I get some time.