Yellow bump stop on ifs?

robh2 · January 27, 2004

I have a yellow bump stop on each side of the front end on my 04 silverady, 6.0, 4x4, auto. They are in contact full time. I have never seen bumps tops in contact until you have alot of suspension travel i.e. bump stop. Could these be for shipping and the dealer forgot to remove them? They have one bolt on the top of them holding them on.

Thanks.

Robert

midnight8100 · January 27, 2004

I wondered the same thing when I first saw those on my '01 2500HD 4x4. I did a double take then went and compared to my '99 2wd (coil spring) which wasn't on the bumpstops. Turns out something about the torsion bar IFS requires these blocks to be in contact all the time (they are progressive). I forget the explanation as to why, but I know they are all like that

robh2 · January 27, 2004

Thanks Midnight. I just drove down to the dealer and they were all like that also, 2 different dealers actually.

Robert

JimWilson · January 28, 2004

Those aren't bump stops, they're progressive rate dampers.

Torsion bar suspensions can't be engineered with a progressive rate of deflection (like coils and leaf spring suspensions can). This is a drawback because progressive rate suspensions handle smaller bumps better, without sacrificing handling or ride quality over larger bumps. GM opted to put those dampers there to give a pseudo-progressive rate to the front suspension.