So this is what I found...

https://www.audiforums.com/forum/b5-...4/#post1426817

 

And the winner is... markymarc... I put the original strut on the questionable front driver side corner and voila! No more shakes/shudder... The shaft of the H&R strut (lifetime my ***) actually wobbles and leaks oil when compressed. Thus, I've found the culprit thanks to you.

Also, I am never again installing the fronts on my own. This was a total bitch. The spring compressor I had wouldn't fit into the H&R coils so I had to run the coil over unit to my friendly indy shop who undid it for me and reassembled using the original shock + H&R coil. Also, it was a pain trying to fit the shock back into place.... Nothing is easy in this freakin car. I could have done all 4 corners in my old M3 with the time I spent on one corner. Handling wise, I can't really tell the difference between the right side and left side. It's possible that the passenger side is so old that it just acts like the original shock.

So now the question is.... do I put in the original shock on the other side or do I get new Bilstein Heavy Duty shocks for the front?

 

IF they are lifetime, can't you get them replaced for FREE? Warranty?

I wouldn't mix and match..don't remember if it's a quattro or not, but put the same on the front on both sides...like I said, my springs broke doing this, had they NOT broken in the compressor, I would have put them back on and they would've broken later on

I would see if THEY warranty both sides, get 2 or 4 for free......