[stressdoc]

Wow, really glad you did not get injured. Bilstein should be concerned. If there is no damage to the upper strut mount that is a tribute to our E9xs being built tough.

I had a Bilstein strut damper pull apart on a BMW 2002, but it happened while rallying off road. The front corner was raised about 3 inches and just banged when compressed. Oil everywhere.

I am hoping to eventually upgrade my BMW perf dampers/yellow springs to the ASTs/Swifts. As soon as they go on sale again (!?) I will snatch a set.

I would recommend the switch to the M3 brace; that should be bundled with the ASTs.

[IN54NITY]

Why don't I see McPherson strut spring compressors in any photo, and why weren't you wearing eye protection? Glad you're Ok.

Originally Posted by ajsalida

edit: I guess the piston + part of the rod could have come off inside the shock, that might explain it jamming. You'd have shock oil everywhere though.

I think you're dead on, you can compress air, but not liquid, this would explain why he said it was very pressurized, fortunately the oil stayed at the
bottom due to gravity.

[BrianMN]

Originally Posted by stressdoc

Wow, really glad you did not get injured. Bilstein should be concerned. If there is no damage to the upper strut mount that is a tribute to our E9xs being built tough.

I had a Bilstein strut damper pull apart on a BMW 2002, but it happened while rallying off road. The front corner was raised about 3 inches and just banged when compressed. Oil everywhere.

I am hoping to eventually upgrade my BMW perf dampers/yellow springs to the ASTs/Swifts. As soon as they go on sale again (!?) I will snatch a set.

I would recommend the switch to the M3 brace; that should be bundled with the ASTs.

Yeah, it was pretty nuts....mostly because I've never had this happen to a shock before....at least not fully seperated like this.

Definitely recommend the ASTs!

Originally Posted by aleckzandr

Why don't I see McPherson strut spring compressors in any photo, and why weren't you wearing eye protection? Glad you're Ok.



I think you're dead on, you can compress air, but not liquid, this would explain why he said it was very pressurized, fortunately the oil stayed at the
bottom due to gravity.

I dont' think you're understanding what was happening in the photos.

Are you referring to a McPhereson strut compressor that is mounted on the wall? (Which would be useless) or the simple spring compressors where you have 2 sets of longs bolts/hooks? That would also be useless in this situtation as the spring was fully expanded. Rather, the spring could float up and down 3 inches the entire time...

There was a bit of oil on the wheelwell that was forced/sprayed by the seals.

[sappersix]

BrianMN, glad you're okay. The blowout must have scared the living daylights out of you. I know it would have me...

Also, I see the posts in this thread regarding the fronts sticking up and interfering with the stock tower brace. Why are the pics different in this post? Older version of the AST 4100s? Just curious... http://www.e90post.com/forums/showthread.php?t=334336.

[neoduffer]

Originally Posted by sappersix

BrianMN, glad you're okay. The blowout must have scared the living daylights out of you. I know it would have me...

Also, I see the posts in this thread regarding the fronts sticking up and interfering with the stock tower brace. Why are the pics different in this post? Older version of the AST 4100s? Just curious... http://www.e90post.com/forums/showthread.php?t=334336.

I think it is because BrianMN has camber plates and Former_Boosted_IS doesn't.

[IN54NITY]

Didn't realize the springs had no compression in your case.

[sappersix]

Originally Posted by neoduffer

I think it is because BrianMN has camber plates and Former_Boosted_IS doesn't.

Gotcha. Thx.

[ajsalida]

Still thinking about the failure mode here, or what may have happened. It could be that the lower rod seal of the internal shock body let go, allowing all the oil inside to drain into the strut housing. Either all of a sudden or over time. This would cause the bottom of the shock body to smack into the oil, over and over, which is as aleckzandr pointed out, incompressible. It would also act liked an air pump, pumping up the air gap between the leaked oil and bottom of the shock body.

In order for the strut to come completely apart though, the rod would need to break off either at the base inside the strut housing, or inside the shock somewhere. If it was inside the shock then the oil would leak out as above and cause more havoc.

One way or another both must have happened: the rod breaks off and the shock oil comes out or vice versa. What a weird failure, I'm sure the bilstein engineers will be fascinated.