540i rear shock absorber fail?

[MSB123]

(Backstory)
Was driving over some bumps at a reasonable (read somewhat quick) rate of speed, nothing worth writing home about, nothing I haven’t done before many times (is on my was home).
This time however, I heard quite a large noise, like bottoming out the car on concrete, but I new I wasn’t moving fast enough for that.

(Problem)
I got home and as it turns out the rear drivers shock absorber has broken, the spring mounting plate (the one built into the shock), has fallen all the way down to the wheel carrier, and the spring is for all intents and purposes lose and useless. I have ordered a new shock (these are OE, I don’t use aftermarket parts), and wanted to see if anyone her has any ideas as to what could’ve caused the failure. This is a major failure of a pretty important part, and I want to be sure it doesn’t happen again.

Anyone have an experience to share?
Any and all info appreciated!!

[StephenVA]

20 years of speed bumps and pot holes.....

[Ed CT]

20 years of speed bumps and pot holes.....

This pretty much sums it up. As much as we love our E39's they are still depreciating assets. A few years ago I was rolling to a red light over a few minor road bumps and hear a loud bang from the car's rear. Didn't notice anything different while driving, but under close inspection a few days later I found that one of the rear springs had broken off at the bottom due to corrosion. Things break, even the important parts.

Replace both rear shocks at the same time (you're prolly going to di this but just pointing out the obvious).

Other things to consider:
Where has the car had its life (sunny CA or rustbelt NE?)
Need to replace the springs + other hardware along with the shocks/struts?
Want to upgrade your rear speakers? Now is the time to do it.

[MSB123]

Sorry- should’ve clarified. Car is a Southern California car, no rust anywhere. These are new rear shock absorbers. I did an entire suspension refresh two weeks ago. All wear items were replaced. This was a new sachs shock absorber from FCP. I wish it was a wear item issue, but with only ~1000 miles since install it begs the question.

[JimLev]

Post a pic of the shock if you can.

[Ed CT]

Sorry- should’ve clarified. Car is a Southern California car, no rust anywhere. These are new rear shock absorbers. I did an entire suspension refresh two weeks ago. All wear items were replaced. This was a new sachs shock absorber from FCP. I wish it was a wear item issue, but with only ~1000 miles since install it begs the question.

In that case, a two-week old shock that breaks sounds more like a warranty issue. Possibly caused by a manufacturing defect. As Jim says, get a pic of the shock and the broken-off piece (if available). FCP is a great company to deal with, and Sachs is a good product. Shouldn't be an issue getting a refund for the strut. Not too sure about labor reimbursement.

[BimmrMeUpSnotty]

Jeez, man, I hope Sachs hasn’t started manufacturing in lame old China…..

[MSB123]

Ouch. I will get a pic in a bit. Already going to get a new one from FCP, sure they will honor their warranty. Just sucks after so much labor to remove the old one and now have to redo it all.

[Ed CT]

Yes, lots of labor for that work. IIRC, it's like 4 hours labor to get at the rear shock, and 10 minutes to replace it.

Maybe a good idea check out the shock on the other side, looking for cracks or defects in the same spring perch area.

[Chedley]

Are you sure you installed "new" Sachs shock absorbers, and not rebuilt or chinesum shocks ??
They should last 20+ years, not a couple weeks.
Which reminds me that it is time to replace mine, I am still driving with the original rear shocks on this car.

[MSB123]

Have removed the broken one and preparing to install the new one from fcp
https://imgur.com/a/iSMPCP5

[BMW540san]

Sorry to hear that but this is the age of global economy where manufacturers (not all but many) prioritize the cost saving over quality.
The only strut / shock I believe in and use on all of my vehicles is yellow Bilstein B6 (HD) which is stilll made in Germany and I've never had issues with them.
On the other hand, I believe black bilstein B4 is either made in Romania or Russia and I've heard some issues with its quality.

[MotorMouth93]

This is one of the most bizarre failures I've seen of a new part. Glad nobody (or the car!) got hurt.

Are you sure you installed "new" Sachs shock absorbers, and not rebuilt or chinesum shocks ??
They should last 20+ years, not a couple weeks.
Which reminds me that it is time to replace mine, I am still driving with the original rear shocks on this car.

He mentioned multiple times he bought a Sachs shock from FCP, highly unlikely that its fake. Do you not read threads before replying?

[MSB123]

Mostly the car lol. Glad all safe.

[01BMWs]

when I took apart my rears....

dead sachs shock.jpg

replaced with Bilstein B8s/Eibach sports