Complete failure of new rear shock mounts

[xuno_gil]

Can someone give me some idea of what could have happened here?

I just did a lot of suspension work on the car, part of that was new rear Lemforder shock mounts.
Less than 100 miles in, I started to feel something was not right, less than 25 miles later I knew something was not right. I checked the rear mounts and both had completely separated.

I have a picture below, has anyone seen this before?
Any ideas what could have caused this?
I am purchasing new ones but this makes no sense, the shocks are new blisters and are not seized or anything.

I am curious to hear what anyone has to say on this. Both rears were exactly like the picture I am showing.

[roguetoaster]

Did you have a plate/washer like what's beneath the nut shown under the mount as well?

[xuno_gil]

No? The kit did not come with one.
Should there have been one in the bottom as well?

[roguetoaster]

Yes, your originals should have had one, and they might function as an upper travel limiter to prevent the isolator bushing from popping out.

[Vincenze]

Do you have the part #6?

https://www.realoem.com/bmw/enUS/showparts?id=1113-USA-02-1991-E30-BMW-325i&diagId=33_0327

Kits often tell you to reuse or buy a part from BMW because it's relatively cheap.

[reelizmpro]

Did you reuse the tube ? #5 and 6 should have kept that from happening. Bilsteins have been known to punish OEM rubber mounts since forever and is one of most common E30 failures. That's why there are so many aftermarket poly rear shock mounts.

[Victell]

If you go aftermarket, then I recommend Rogue Engineering rear shock mounts (rubber). After blowing stock mounts and 'heavy duty' mounts on my car about once a year, I put the Rogue's on and haven't had a problem in years. The Rogue design also allows you to change the shocks from the bottom, without having to remove the annoying trunk trim panels.

Cry once and never have to think about them again.

[mjweimer]

If you go aftermarket, then I recommend Rogue Engineering rear shock mounts (rubber). After blowing stock mounts and 'heavy duty' mounts on my car about once a year, I put the Rogue's on and haven't had a problem in years. The Rogue design also allows you to change the shocks from the bottom, without having to remove the annoying trunk trim panels.

Cry once and never have to think about them again.

+1 for the above recommendation.