S4/S6 Suspension

[URSIMPO]

Does anyone know if there is a difference in front shock absorbers between the S4 and S6?
I removed the front Bilstein shocks from the S4 and put them in the S6. I did the cap up nice and tight, but the shock can move up and down about 2mm.
When driving along it feels like something is loose because of the play.
Does anyone have any suggestions?

[saltinot]

The shocks are the same dimensions.

Make sure that you have the cap on VERY tight. I always wrap the bottom of the shock a couple of times with some duct tape. The tape is there if the shock moves in the tube it will not make any noise.

[URSIMPO]

ok, thanks for the advice. although the tool that Bilstein provide is a really bad design and the lugs keep slipping out of cap.