Just Installed new rear shocks - royally disappointed

The rear shocks are attached to the subframe only, not the unibody.



If the back feels lik it is "crashing" then most likely the rear carrier mounts are bad.

You can only really inspect them if you support the rear subframe, remove a bolt and large washer at the bottom of the bushing and visually inspect the rubber surrounding the center metal sleeve that the bolt passes through.

Here is a cut-away pic showing the center metal sleeve and the rubber at the bottom:



You can't inspect without removing the bolt(s).

i did half and half... With Hd's on my 540... and i got exactly what i wanted... I stock tight ride...

im @ 165k

its safe to assume you replaced the tops as well? correct?

Jason - you are a rock star! Thank you very much for the photos. Looks like I know what the problem is now. Any tips on installing new ones? Anything to watch out for? I'm sure there's a thread that talks about it. I feel like I should pay you...

Originally Posted by Jase007

The rear shocks are attached to the subframe only, not the unibody.



If the back feels lik it is "crashing" then most likely the rear carrier mounts are bad.

You can only really inspect them if you support the rear subframe, remove a bolt and large washer at the bottom of the bushing and visually inspect the rubber surrounding the center metal sleeve that the bolt passes through.

Here is a cut-away pic showing the center metal sleeve and the rubber at the bottom:



You can't inspect without removing the bolt(s).

Just wanted to say that is a badass analysis

Hi Cambrian and Chocodile.

As a sufferer of exactly the same symptoms on my '99 528iT (220K mi), I'm following this thread with great interest. Have you had the carrier mounts replaced, as Jase007 suggested may be the cause? Have you resolved the problem?

I'm not afraid of high-mileage cars - this is my third over-200K car ('84 Audi 4000 - 510K, '92 525i - 240K). I plan to give this car to my son and buy another E39 Touring and I'd like to pass this car on with a smoother ride.

BTW, I think the E39 Touring is the most beautiful wagon ever built. The newer 5 wagons are awkward looking.

Hey hexhead,

Yes I did replace the bushings (carrier mounts). I rented the tool from Jase007, and he was extremely helpful answering questions and helping me along the way.

The whole job was pretty easy. The old ones came out as easy as the new ones went in. The old ones were beyond shot. They were cracked so badly, they were leaking fluid on the garage floor. Definitely needed to be replaced.

The ride is definitely better, but still not what I consider smooth. Jase007 suggested new tires, although the Michelins I have on it are only a couple years old with maybe 15k miles on them.

I'm wondering if my situation is unique. The car was a lease vehicle when it was new, and I've always wondered what kind of abuse it suffered. There are all kinds of cracks in unusual places throughout the car. Almost makes me wonder if it was dropped.

I love the car, and I agree - it's the best looking wagon ever built. (I'm not a fan of the new BMW styling either). I'm just resigned to a fairly loud rough ride now.

My advice is to definitely replace the mounts. It made a big difference, even if it didn't completely fix my problem. Hopefully it solves your problem. Everyone else who replaced theirs has said it solved the problem.

Good luck, and definitely reach out to Jase007 with questions.

Thanks very much, Chocodile. I'm putting this job on my list. Glad I found this thread and the helpful folks on it.

Well I'm still on the hunt to figure out why the rear suspension on my 2000 528 wagon is still so rough, even after new shocks and subframe bushings.

Jase007 has been extremely helpful in pointing me in the right direction. He suspects that the KYB Gas-a-Just shocks I installed may be too stiff, and not allowing enough recoil from bumps. The symptoms are the same as before: loud, jittering over abrupt bumps. It's especially noticeable on corners, and it feels like the tire is bouncing off the road, and actually feels like the rear bounces sideways. Not very comforting on mountain roads.

After doing more research, it looks like the problem might also be with the control arms and ball joints. There is a fantastic DIY on this subject that details the complete rebuild of the rear suspension - http://www.bimmerfest.com/forums/sho...d.php?t=545345

But before I go down that road, here's my question:

How can you tell if the control arms are bad? My mechanic friend looked at them tonight, and said everything looked tight - no unreasonable play. I can twist the control arms slightly with my hand, but that should be normal, right?

Also, my problem is with the vertical ride, not lateral. I believe the control arms and ball joint only affect the lateral movement of the suspension. Is that correct?

Any advice is greatly appreciated.

Have you ever checked the rear tire pressure?
KYB's...had them in my 300ZX, the rears both bound up and the ride was terrible. Not sure that is your problem, but it might be good to unbolt one end and see if you can compress them fully.

Originally Posted by JimLev

Have you ever checked the rear tire pressure?
KYB's...had them in my 300ZX, the rears both bound up and the ride was terrible. Not sure that is your problem, but it might be good to unbolt one end and see if you can compress them fully.

Yah, I've been experimenting with tire pressure. Jase007 also suggested that the Michelin tires I have might be contributing to the problem.

It's just really hard to believe that any one of the possible causes would create such a rough ride. Probably more of a cumulative effect. Just trying NOT to throw huge sums of money at this before I know exactly what the problem is.

I'm gonna take it to a BMW specialist, and see if they can diagnose the problem. This will be the 3rd time I've had a shop look at it. They must think I'm losing my mind.

What Michelins are you using?
On the rear I have 265x40x17 PS2's, they ride fine at 39PSI.

I have the stock rims, and the Michelins are Pilot Sport A/S 225/55 ZR16 95W M+S.

The recommended stock tires are 225/60 R15 96 H M+S.

FWIW, I run 35psi cold F&R in my car, my 335 and wife's C300, my old Lincoln etc.... excellent results. When I got my 530 the tires were worn in the center more than the edge, heavily. Indicating over inflating. I read into this when I got my car and it's basically for very high speed driving long distance with a fully car. Tire deflection bla bla... I run 35psi cold, check it 2x month on a sat morning and am able to get 80-100k from a set of tires usually. I did 48k on factory Michelins and they still were at 65% left when I sold my Lincoln. And did 84k from factory tiger paws on the company car.

As for the shocks, I've been thinking that maybe next year I'll do the shocks and all the suspension items but this just seals the deal for me... OEM BMW shocks. I love the way my car rides and handles even with 102k on it.

Choc:

I run 35 psi all around.

I like JimLev's suggestion of undoing one end of the rear shocks and see if you can compress by hand ... eliminates one more variable.

FWIW: I have old control arms and ball joints on the rear suspension of my touring ... and there is no hop or jump or abnormal ride. I have only replaced rear carrier bushings, shocks (BMW supplied SACHs Sports), air springs (sport) and tires. Ride is smooth and what I believe "normal" for a sport touring. Rear end doesn't step out or skitter in corners and large and small bumps are a non-issue (road undulations, RR tracks, expansion joints, small pot holes, etc...).


Happy Turkey day BTW.

I had a similar experience with my 1995 E34 wagon with the suspension giving an extremely harsh ride even after installing new shocks. The rear design is different from your E39 so it is not an apples to apples comparison but here is what I found. After replacing everything including rear subframe bushings, I decided to try new coil springs. New M Technic springs from the euro version of the E34 Touring cured my problem. Apparently, my original springs had worn out and no longer had the proper spring rate. I was extremely reluctant to believe this as a possibility until I replaced them. The ride was transformed when I did. The original springs had about 125K miles on them when I replaced them.

Thanks for the info, guys. I have been running 32-35 psi on all tires since they were new. The KYB shocks are only 10 months old, so I'm reluctant to spend another $300 to replace them. Here's my plan: New tires first, then see what kind of ride I get. I'm suspecting it will be improved, but not cured. If still bad, I'm gonna replace the control arms and ball joints (111k on car). If that doesn't fix it, I'll look at springs and shocks. If that doesn't fix it, I'll find a cliff, and push the car over the edge. :-)

Speaking of tires, the consensus seems to be Continentals. But I'm looking at Kumhos that have a 600 treadwear rating and softer ride. Less performance, but softer ride.

Thoughts?

how would a 600 index tread wear rating produces "softer" ride?
It would be the opposite, imho. truck tires have 600 indexes...i've yet to ride in a truck that delivers a "soft" ride...

fwiw...i'd stick w/ continentals, and if a soft ride is a priority, get all seasons dws. they're more pliable to work for snow conditions,. this is the key to a softer ride.

Sorry for the confusion. I wasn't saying the 600 rating would render a softer ride, just that it's a pretty high rating. I'm actually looking for both - treadwear and soft ride. Seems like it's a toss-up between the Kumho LX Platinum and the Continental Extreme Contact DWS.

I had a bad experience with a previous set of Kumhos, but they were the AST's, so it's not apples to apples. I'm leaning toward the DWS based on reviews. People who have the Kumhos love them, but there are not nearly as many as Continental owners.

The Kumhos are 600 and the DWS are 540. Kumhos are slightly deeper tread.

Decisions, decisions...

Ok, here's an update:

I just installed Continental Extreme Contact DWS tires over the weekend. Huge improvement. Quiet, smoother ride. But, the jittering persists on bumps - especially on corners. Next step in my process of elimination is to replace the shocks. Bummer, since they are only a year old. I'm going to go back to Sachs Boge OEM shocks. Sure hoping that cures my problem. My wallet (unlike Congress's) just isn't big enough for endless spending...

I replaced my 2002540iT rear shocks with Bilstein (not HD) but the exact replacement part number for my rear Sachs sport (S227A) shocks. They are black in color and have the Sacks/ BMW part number on them: Sport suspension+lowered+ride-height
33521094057. However, all those Bilstiens are gas filled and could be a tad firmer. I just this weekend R&R'd my rear sub-frame bushings and rear shock mounts for the 1st time at 94500 mi. Now, the rear end over small road bumps is not noticeable. The rear shock mounts were noticeably deformed, one rear sub mount starting to crack. just like tires, all that rubber goes bad after years. at the time the original Sachs/ sport/ touring rear shocks were way too expensive....so I tried the Bilstein Touring. Works well. If anyone is interested, I have a set of new, unused, boxed rear Bilsteins *non-sport/ lowered* for replacing BMW P/N: 3321095096...if anyone wants to try them.

Choc: Any update?? I would try to swap out your shocks with a used OEM set and see how it rides. Do you know anyone else using KYBs? Maybe you can ride in their car and see how it is. I'm suspecting the shocks.

I used KYB gas shocks on my 1988 735i for years in conjunction with M-tech sway bars front and rear to enhance handling without too harsh a ride. The KYB's didn't last very long and had a slightly bumpier ride over small stuff probably because of the gas.

having the same issue with my touring as well. hard rear end crashing over bumps, and it has coil springs. Ill definitely subscribe to this thread. I have 122K on mine.

Originally Posted by 4thBMW

If anyone is interested, I have a set of new, unused, boxed rear Bilsteins *non-sport/ lowered* for replacing BMW P/N: 3321095096...if anyone wants to try them.

i am having a hard time cross referencing that part number. could you double check it? are they the same as these? BE5-6096-H0.

G~

That sure isn't correct. Try this number at Bilstein USA site: 19-106649 (BNE-A664). Reference 1999 540iT non-air lift. Did you see my message to you with this info?