[rtc303]

I've been looking to replace the shocks in the rear of my '06 330xi. I'm sitting around 95k miles and they are bouncing around way too much. So I finally got around to ordering some Bilstein HD's with the matching install kits from Bav Auto (non-sport).

Its my DD, so I'm pretty much forced to drive it until I get the parts in. The only problem is the shock or upper shock mount on the drivers side failed before I've received the new parts. I'm not sure exactly what caused it, but the shock's rod sticks out an extra inch or two out of the top of the upper shock mount in the trunk.

If you look at


I have tightened (A) as much as possible, but it still sits about an inch off the body when looking in the trunk. I'm guessing something collapsed, maybe (B-D) but haven't had time to jack it up. Needless to say, when I drive it rattles like an SOB. Think i am causing damage while I wait for the parts?

[BKV122]

I think i may have had the same issue as you happen to me awhile ago with the rod of the shock and A sitting higher than normal and rattling around. What i found was Item D failed and the "seat" it sits on or that lip on the shock rod went through the hole of D and D moved its way down.

My opinion take it really easy, the only damage i cause was around the top part where item A would rub against the truck sheet metal. Other than that my car was my DD and i drove about 100 miles till my replacement parts came in. No issues

[benjlv]

if it were me, i would measure the diameter of the shaft above the lip and get a washer with similar inner diameter that will fit on there from the hardware store. then use the washer to keep D on the other side of the lip where its supposed to be. Then put it back together. should be good as new if done correctly.

if you leave it apart its going to bang around (i dunno if that will cause damage) and youre going to have very poor traction on that wheel without the damper helping the wheel setting down.

at thea last maybe wrap a rag tightly around the shaft to at least cushion the blows.

[jwzimm]

Could you take the shock completely out? You should be able to do that without anything more than taking the wheel off. It would bounce around horribly on that corner though. Maybe find a local that has swapped their suspension out and grab a shock off them for temp install.

[rtc303]

Originally Posted by BKV122

I think i may have had the same issue as you are now with the rod of the shock and A sitting higher than normal and rattling around. What i found was Item D failed and the "seat" it sits on or that lip on the shock rod went through the hole of D and D moved its way down.

My opinion take it really easy, the only damage i cause was around the top part where item A would rub against the truck sheet metal. Other than that my car was my DD and i drove about 100 miles till my replacement parts came in. No issues

If I didn't know better, I would have thought you were inside my trunk, taking a picture of my suspension. That is exactly what happened! Thanks for the suggestions guys.

I like the idea of putting a buffer/rag around the shock rod to prevent (A) from banging around. However, I would be nervous of it somehow getting snagged on something and then wrapped around my axle, etc.

BKV, you mention that you had a bit of damage from (A). Was it just cosmetic damage where it rubbed? I figure the carpet could just cover that up. I am more worried about weakening the body piece where the upper mount connects.

[BKV122]

Yea the only damage was cosmetic, but like you said it gets covered up with the rug and rubber cap. I installed the new items with no issues

[ajsalida]

Originally Posted by benjlv

if it were me, i would measure the diameter of the shaft above the lip and get a washer with similar inner diameter that will fit on there from the hardware store. then use the washer to keep D on the other side of the lip where its supposed to be. Then put it back together. should be good as new if done correctly.

if you leave it apart its going to bang around (i dunno if that will cause damage) and youre going to have very poor traction on that wheel without the damper helping the wheel setting down.

at thea last maybe wrap a rag tightly around the shaft to at least cushion the blows.

This is a very good idea.

You other guys have any idea how this happened? That cup does not just wear out and punch itself over the lip on the rod. Could something have been taken apart and then put back together wrong or missing?

[scotty_miller]

Did you put the rubber piece (c) in the diagram and still that issue? I have part that is c labeled in my hand in the diagram. That takes up a pretty good amount of the shock shaft

[ajsalida]

Yeah I cannot figure how it would happen if assembled correctly.

[rtc303]

I can't speak for BKV122, but I've never disassembled my rear suspension on this car before. I tightened up (A) once about a week ago, as it was loose and I was starting to hear this same noise. I don't think I overtightened it though, I just think it was already starting to fail as I had heard the noise. Although it did not protrude this bad.

Aside from maybe the tightening affecting it, I live in the salt/rust belt, which includes many potholes that look like works of art. Once I disassemble it, I'll take pics and see how rusted everything got.

Oh, I almost forgot, the parts are delayed 1-2 weeks! I got an email a day after I ordered them saying they were delayed. Why couldn't I have been notified earlier?!? I'm def going to have to cancel as this is my DD and re-order them. That just burned another day...

[ajsalida]

Will be interesting to see if anything is missing, maybe previous owner did something. Or maybe the rubber underneath rots, leading to looseness, then a gap that hammers over time.

[rtc303]

Yeah, I'm guessing it was rot/gap that hammers over time. I've had the car for the past 5 years (CPO) and I don't think the previous owner did anything before I took ownership (~35k miles). I noticed the noise for a couple weeks, probably should have taken care of it then!

[rtc303]

It looks like it'll be a few days at least, even if I can get my order straightened out soon.

Like benjlv suggested, I might try jacking my car up and putting a thick washer on the shock so (D) doesn't slide down. Since its currently -1 degrees here and plenty of snow, think I could do this without removing the shock? I would have to take off the lower top shock mount hardware and then place the washer on the shock.

[ajsalida]

Originally Posted by rtc303

It looks like it'll be a few days at least, even if I can get my order straightened out soon.

Like benjlv suggested, I might try jacking my car up and putting a thick washer on the shock so (D) doesn't slide down. Since its currently -1 degrees here and plenty of snow, think I could do this without removing the shock? I would have to take off the lower top shock mount hardware and then place the washer on the shock.

Well if it turns out the rubber is all gone, then all you'll do is make it hammer more. You'll be bringing the metal cup up closer to the top of the fender well but still have a gap and no rubber. You maybe want to do the washer, then kludge up some sort of padding above it so there is no metal on metal contact.

Like the other guy said a maybe rag or something, duct tape around it so it doesn't go anywhere but you do not want bare metal cup whacking against top of unibody. At some point you could break the strut rod on the shock or damage the lip. I am sure the cup is softer metal (so it bent) for just this reason.

[ajsalida]

I still don't see how both the pieces above the cup can disappear. Very common install error to leave them out or wrong order, at some point in the past perhaps this was done. There is a bonded metal sleeve inside #6, and the black cap is a weather boot/seal that fits over 6 and the cup. The top nub of 5 fits up into the hole in the fenderwell:

[rtc303]

I'm not 100% sure, but I believe the pieces are actually still there. I will check it tonight and report back.

How I thought it worked is that (4) sits on the ridge of the shock rod. This piece in turn holds (5) and (6) up at the correct height.

So what I thought happened is that (4) got bent out of shape and eventually its hole was too large and it slid down over the ridge to the top of the gas tube. This led to (5) and (6) sliding down too because they rest on top of (4).

This would allow the shock to fully extend itself since (4,5,6) no longer stop it. So now it sticks out an inch or so into the trunk.

Thats pure speculation. I'll check it out tonight and let you know. If this is the case, could I do the washer trick?

[ajsalida]

Originally Posted by rtc303

I'm not 100% sure, but I believe the pieces are actually still there. I will check it tonight and report back.

How I thought it worked is that (4) sits on the ridge of the shock rod. This piece in turn holds (5) and (6) up at the correct height.

So what I thought happened is that (4) got bent out of shape and eventually its hole was too large and it slid down over the ridge to the top of the gas tube. This led to (5) and (6) sliding down too because they rest on top of (4).

This would allow the shock to fully extend itself since (4,5,6) no longer stop it. So now it sticks out an inch or so into the trunk.

Thats pure speculation. I'll check it out tonight and let you know. If this is the case, could I do the washer trick?

If you still have 5 & 6 by all means do the washer thing until you have parts. Make sure the steel sleeve is still inside of 6.

The question is how could the above happen? I don't see a failure mode with all the right parts in place that punches the shock rod up through #4. 4 is supposed to be flat. Maybe an accident or monster bottom out event?

[BKV122]

If the pieces above the cup weren't installed you would have heard alot of rattling.

If your lucky you'll be able to remove item D/4. Mine was stuck on there pretty good. But a large outside diameter washer would do the trick for the time being.

As for how it happened, parts always fail no matter how perfect its put together, shit always happens. Over time, with 80-90k miles, it'll eventually fail.

[rtc303]

It looks like the shock rod started corroding and so did the lip on (D). Eventually the lip expanded and (D) fell down the shock.



I'm sure the tons of salt they dump on the roads around here doesn't help. Anyway, I tried to pry D up and off the shock, but it wasn't going anywhere. Mine is stuck on just like BKV122's was. Unfortunately I wasn't able to do the washer trick.

I re-ordered some Bilsteins from a different company, and they should be shipping out tomorrow. The noise coming from this is the worst.

[jwzimm]

If you got that far why didn't you just take the shock out?!? It isn't doing anything for damping in its current state and could be seriously damaging the mounting structure so your new shock won't fit up properly.

[ajsalida]

Man that is fugly. It still looks to have been bottomed out hard, no other way to push D past that lip. Are there lowering springs on there or is everything stock suspension wise? Curious what the other side looks like.

[rtc303]

Originally Posted by jwzimm

If you got that far why didn't you just take the shock out?!? It isn't doing anything for damping in its current state and could be seriously damaging the mounting structure so your new shock won't fit up properly.

The mount didn't appear to have any damage done to it. It was -3 degrees out when I jacked the car up. I don't have a garage, so I'm working on a compacted snow covered driveway. Not ideal at all. I wasn't about to get involved with taking the wheel off and messing with a rusted/frozen lower shock mount. I could barely move my hands as it was. Note: I already had the trunk apart from looking at it previously, otherwise I wouldn't have attempted this at all.

Once it warms up, I might attempt to take out the shock. I ended up covering the upper shock mount with a rag and duct taped it up to quiet the rattling. My hands were killing me after that.

Originally Posted by ajsalida

Man that is fugly. It still looks to have been bottomed out hard, no other way to push D past that lip. Are there lowering springs on there or is everything stock suspension wise? Curious what the other side looks like.

Everything is bone stock on the car. I'm replacing both shocks at the same time, so I will let you know how close the other side is. I've heard plenty of pot hole explosions from the streets around here (huge potholes are the norm). Perhaps that contributed to it.

From looking at the shock rod, the lip that (D) sits on has been corroded so the ridge was worn down a bit. I think this led to fatigue in D (with less surface area sitting on the ridge) and it worsened from there.