Questions regarding function of vehicle rubber body mounts

Hi everyone,

I have some questions regarding the functioning of vehicle rubber
body mounts in general, & specifically, rear cab mount bushings for
Chevy K1500 series pickups having conventional two door cabs.

I have included a rapidshare link to a GIF image of an exploded view
drawing for reference here...

http://rapidshare.de/files/40737081/Cab_Mount_Bushings_2.gif.html

Referring to the drawing…

Part # 58 = Upper rear rubber cab mount bushing or cushion
Part # 59 = Lower rear rubber cab mount bushing or cushion
Part # 60 = Round steel retainer that goes under the lower rubber cab
mount bushing
Part # 61 = Cab mount bolt

You can see that the upper rubber cab mount bushing (5 sits on the
top side of a steel support bracket that is integral with the vehicle
frame. The upper rubber bushing is integral with a steel portion of
the bushing. A round / oval shaped steel portion of the upper cab
mount bushing extends downward from the underside of the bushing. The
downwardly extending steel portion of the upper bushing fits through
a hole in the frame support bracket.

The lower rubber cab mount (59) is installed under the frame support
bracket, a round steel retainer (60) is positioned under the lower
rubber bushing, and a cab mount bolt (61) is used to secure the
system to the vehicle frame. The cab mount bolt is torqued to
approximately 55 foot pounds.

Regarding the steel portion of the upper rubber bushing which extends
down from the underside of the bushing, is this portion of the upper
bushing supposed to “bottom out” on the round steel retainer (60)
which is installed under the lower bushing, when the cab mount bolt is
torqued down ? Are the two steel components supposed to be in contact
with each other when the bolt (61) is torqued down ?

I would appreciate any feedback.

Thanks
John