Just Installed new rear shocks - royally disappointed

I just installed some nice new shocks on the rear axle of my 2000 528i touring, and I have to say that I've noticed no improvement in performance. They're Bilsteins, but as I haven't noticed a significant perfoance change, I'll refrain from judging Bilstein. My factory Sach's can be compressed and expanded by hand, albeit at about 1/4-inch per second or two.

I've been experiencing a hard ride and jiggling. The back axle felt worse than the front for hardness, so I started there. The rear subframe bushing were replaced by the previous owner at a BMW dealership about 15,000 km ago, along with the rear stabalizer link. Front thrust arm bushings and front left thrust arm were also replaced at that time.

The car has coil springs, so broken air springs can't be the issue. The coil springs are good based on ride height. I'm not sure what else it could be causing the rigidity.

The car basically drives like a rigidly suspended truck or jeep, and many the dips and bumps feel like someone is punching my backside. I drove about 5 other E39 sedans, prior to driving this wagon, and I thought they drove more like Mercede's E320's or Lexus LS400s and GS300's, all of which are smooth and connected to the road without feeling like a couch with a steering wheel. I never really noticed the suspension firmness/rigidity on my wagon prior to purchasing it, even after 3 test drives. I had noticed a bit of tossing back-and-forth and just assumed it needed new shocks.

Frankly, I don't know where to go from here. Guess I'll see if I can examine the subframe bushings in situ by removing their bottom plates --- if that's possible. Perhaps the previous owner loaded the wagon up with concrete and slamed a speed bump, splitting the relatively-new bushings.

Cambrian:

Support rear of car in air (jack stands).

Support rear subframe via the diff with a jack.

Remove one bolt and large washer at a time and see if "new" bushings are actually: 1. new and/or 2. cracked (void of fluid).

* another possibility is that the previous person that replaced the bushings didn't allow them to set before putting the weight of the car back on the suspension. If that is the case... the subframe can creep up the bushings and potentially bang against the unibody. The subframe should be seated on the wider part of the lower 1/4 of the bushing step out when properly installed. There should be an air gap above the top edge of the subframe where the bushing passes through. The center of the bushing locates on an inverted "V" that is part of the unibody and the bolt passes through the center of the bushing (metal sleeve) and into the threaded "V" of the unibody.


FWIW:

I replaced my 170,xxx mile old rear OEM SAChs sport shocks with new shocks from the dealer (installed Koni rebound adjustable sports on the front), as well as the rear subframe bushings ... car sticks and dampens like new. I'm not a bilstein fan b/c of harsher compression settings but a local touring friend has them on two of his tourings and loves them. Doubt it is the shocks... what did the coil springs look like when you were in there? Did they have OEM markings on them? (part numbers, black paint with a brown stripe on one or two coils?)

Take a few pics?

Thanks Jase007. Will do, but first . . . off to the store to get yet another torque wrench. 120 ft-lb is a lot! Hopefully I don't pull the car off the stands onto my head! Will definitely double up the stands, placing some under the swing arms as well as the jack points. And of course chock the front wheels.

Originally Posted by cambrian123456

Thanks Jase007. Will do, but first . . . off to the store to get yet another torque wrench. 120 ft-lb is a lot! Hopefully I don't pull the car off the stands onto my head! Will definitely double up the stands, placing some under the swing arms as well as the jack points. And of course chock the front wheels.

Put your tyre underneath aswell. Just incase ur e39 drops it won't squash your computer upstairs


Sent from my iPhone using BimmerApp

Which Bilstein Shock did you get?
Sport vs HD?

I installed Bilstein HDs.

I haven't opened them up yet, as I'm waiting for some snow to melt off the car, but I did crawl under with a rain jacket on and examine the exterior of all the bushings. Seems that they're all sitting correctly and have an air gap on top. I attached a picture of a typical one.

Well I took the bottom plates/washers off the subframe bushings and inspected. They look great. Not a sign of wear and tear apart from dirt. That's good to know as they were installed 2 years ago.

Springs look nice. I didn't notice any markings on my passenger spring, but there was a dab of red paint on the driver-side one.

Well, don't know where to go from here . . .

You know, I'm wondering if perhaps the hard ride on the rear end has something to do with the rear tire's being inflated 5 psi more than the front as per the owners manual? I'll have to temporarily deflate them a bit a see if there's a difference.

Upgraded only 1/2 of your shock/strut system and you were expecting to hear church music and see angels flying about? How many miles on your touring?

Originally Posted by cambrian123456

I just installed some nice new shocks on the rear axle of my 2000 528i touring, and I have to say that I've noticed no improvement in performance. They're Bilsteins, but as I haven't noticed a significant performance change, I'll refrain from judging Bilstein. My factory Sach's can be compressed and expanded by hand, albeit at about 1/4-inch per second or two.

I've been experiencing a hard ride and jiggling. The back axle felt worse than the front for hardness, so I started there. The rear subframe bushing were replaced by the previous owner at a BMW dealership about 15,000 km ago, along with the rear stabalizer link. Front thrust arm bushings and front left thrust arm were also replaced at that time.

The car has coil springs, so broken air springs can't be the issue. The coil springs are good based on ride height. I'm not sure what else it could be causing the rigidity.

The car basically drives like a rigidly suspended truck or jeep, and many the dips and bumps feel like someone is punching my backside. I drove about 5 other E39 sedans, prior to driving this wagon, and I thought they drove more like Mercede's E320's or Lexus LS400s and GS300's, all of which are smooth and connected to the road without feeling like a couch with a steering wheel. I never really noticed the suspension firmness/rigidity on my wagon prior to purchasing it, even after 3 test drives. I had noticed a bit of tossing back-and-forth and just assumed it needed new shocks.

Frankly, I don't know where to go from here. Guess I'll see if I can examine the subframe bushings in situ by removing their bottom plates --- if that's possible. Perhaps the previous owner loaded the wagon up with concrete and slamed a speed bump, splitting the relatively-new bushings.

Sounds familiar...

Subframe bushing looks good.

How does the rear integral link, ball joint and control arms look?

Any split boots on the parts in there?

FWIW: I've dropped the tire psi to 33 front 35 rear on my touring. I was initially following the door jamb recommendations but the rear inflation was WAY to high IMHO. Load it up with kids and stuff every day ... have no abnormal wear on standard conti extremes (235/45/17) after a couple of years (30+k? miles).

Thank you for your support Mack . . . given that I've noticed no diffenence between my factory Sachs and Bilsteins, I'm reluctant to install front struts, especially as they're more expensive and difficult to install.

I've got 150,000 km, ie. 93,000 miles on the factory components.

Jase, I did have a look at the ball joints and control arm bushings back there. Couldn't see any cracked/chipped/worn rubber. Integral link = stabilizer bar? It's new.

I dunno man, installing aftermarket suspension usually makes the ride harsher.....

Originally Posted by cambrian123456

Thank you for your support Mack . . . given that I've noticed no diffenence between my factory Sachs and Bilsteins, I'm reluctant to install front struts, especially as they're more expensive and difficult to install.

I've got 150,000 km, ie. 93,000 miles on the factory components.

Jase, I did have a look at the ball joints and control arm bushings back there. Couldn't see any cracked/chipped/worn rubber. Integral link = stabilizer bar? It's new.

Haha anytime man. Yeah lots of discussion on here about Billy HD's being harsher than stock. Still not as harsh as Billy sports though. It's tough dialing in on the perfect suspension and can take much trial and error and what one person likes, feels harsh or loose to another. Good luck bro. Really.

One thing I'm curious about is my springs. They look so new, and I would expect the coating on them to be delaminating after 11 years and 150,000 km. I'm wondering if they may be aftermarket sport springs or similar, although it's unlikely the previous owner would have upgraded the springs and not the shocks. Does anyone have pictures of their factory springs ? Rusty or not? Delaminated or not?

Might be that the front struts are so worn by now that the helping action of the new rear shocks are of no benefit---after mounting the shocks on my touring it felt some better but after installing the front struts
the ride I thought was better than new---Do you have the fronts struts ready for installation--try that fisrt and see what you think--Bilistiens in my mind were much better than the OEM and and better on my wallet

My Toronto car's springs are delaminating. FWIW.

Poolman, when you say better than new, are you implying that you can't feel the bumps and dips?

I put new struts all the way around with new perches, new spring pads (maybe same a perches) bearing plates all around, and new rear ball joint. Dont forget the sway bar rods. The first thing i noticed is the car now rides about 3/4" higher. Its definitly firmer. The only problem I have is it still squeaks when going over stiff bumps. I have poly bushing in the front end from last year. I am hoping that the firmness calms down and the squeaking goes away. I am more of a soft firm ride kinda guy. Anyone know what might be causing the squeak?

All work was done over xmas vacation so the parts are still fresh!

I'm very late to this thread, and new to the forum. I have EXACTLY the same issue on my 528it wagon. It's a 2000, and I just did new struts and shocks all around. Car has about 106k on it, and the ride was becoming increasingly rough - particularly noticeable at slow speeds (25-35 mph) on abrupt bumps, like expansion joints in the road. I installed KYB's, not Bilsteins or Sachs. A buddy who is a BMW guy recommended them. The front is smooth as silk, but the rear "crashes" every time I hit a bump. All the joints, springs, bushings check out. My BMW guy (former BMW mechanic) and I can't figure it out. Really hoping one of you guys has a suggestion. Thanks in advance.

Look at my post #2 above and inspect your rear subframe bushings.

New shocks and other suspension components will highlight the subframe crashing into the under side of the unibody (car).

Post a pic when you are done.

Most of us with 110k + miles (or 10+ years) have had to replace the subframe (rear carrier) bushings as they are fluid filled for NVH and don't last forever.

* some KYBs are adjustable, in that when you rotate / click them the compression and rebound dampening settings move together ... towards stiffer (if that is how you adjusted them).

the wagons aren't as solid as the sedans, have you driven another wagon to compare?

Thanks, guys. Yah, we checked out the bushings and all the other suspect areas. We had it up on a lift and did a front and rear alignment. Could it be that the bushing are actually bad, even though the visual and pry-bar inspection says they're still good?

Oh, and no, I have not compared mine to another wagon, but when I bought mine in 2007, it had a firm but very comfortable ride. It's just been steadily getting worse, and the new shocks did not make a noticeable improvement. It almost feels like the suspension is riding on the bump stops, so that every bump is jarring and vibrates.