shaky cab..?

[shortchevy84]

i have a 84 1/2ton, and lately it seems as though the cab sort of shakes when i hit bumps. it didn't do it when i first bought the truck. i can't tell if its the whole cab, or the seat, or maybe the doors, but it definitely isn't right. my friend also has 84 1/2 ton, and his rides so much smoother. my shocks are new. springs are old and mine is shortbox compared to his long box, but it almost feels like the whole cab does a little shake when i hit some little bumps. anyone heard of something like this?? are there just simple bolts holding the cab to the frame that possibly could have come loose and/or broken? thanks for any input.

[roundedline]

There are 4 cab mounts that support the cab above the frame.  They have rubber bushing on them from the factory and they secure the cab with bolts.  2 are on the front outside part of the frame where you fee would be, the other 2 are at the back of the frame and between the framerails.  You could check those for wear.

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

[80stepsideguy]

I had the same exact problem in my 80.When we drove it it bounced up and down.Turns out the body mount perches were so corroded and rusted away the body mounts fell thru the holes.The 2 rears on the cab were ok but the 2 under the front part of the cab were wasted.So i jacked up the front part and the bolts were so rotted that 1 turn of the rachet they snapped, the mounts broke apart in my hands .I ended up welding 1 inch plates that contoured the spring perches and welded them in solidly and had a hole cut out perfectly round to accodomate the body mount on each side.Now they sit great and no more bouncing.But i am gonna remove the cab and put the frame on a rotiseree and make them look right.
thanks
pat