1977 gmc k3500 crew cab wheel hop

[4x4k20]

I have a 77 k3500 gmc crew cab it rides ok but does have wheel hop around 40 to 50 mph the tires are 35s that are balanced .......it does not hop all the time just sometimes.also I have reg. cab 79 k30 it does the same thing but not as bad as the 77 crew has a 4inch lift the front springs are soft ride springs.and I used ord zero rates ... the rear springs are stock with 4 inch blocks ...... the 79 has a set of 38s and 8 inch lift springs front and rear .. just wondering what could be causeing this hop it seems to be the front end thats doin all the hopping.. the 77 has new 5100 blistein shocks ..one of the front shock bushings have already worn out . but it was having the hop before the bushin wore out .. any ideals ? I have thought about removeing the front stabilizer bar to see if that would help I have owned several of these trucks and allways used the stabilizer bar with no problems.so I don't know how it will do with it unhooked .

 

[shady]

Death wobble.
Try searching it here. Usually means your kingpins need serviced. New bushings n springs for them.

 

[76zimmer]

I don't think he's talking death wobble?
sounds like better balancing is needed, check spring bushings, check for loose suspension parts, and maybe some shock tuning?

 

[SpeedlabDan]

...and lose the blocks

 

[Justin V]

You don't think that's just an easy inch?

 

[4x4k20]

no its not the death wobble I had that before on crewcab dually I know what its like .. my truck hops its like the front tires are out if round it acts like a big set of tittes bouncing up and down

 

[obijuank5]

Jack it up. Spin the tires and watch the runout. Measure the tires "roundness"

Rotate the tires, see if the hop follows a particular tire.

 

[SpeedlabDan]

Jack it up. Spin the tires and watch the runout. Measure the tires "roundness"

Rotate the tires, see if the hop follows a particular tire.

True, balancing doesn't always tell how out of round the tires are. Larger the tire the more effect on wheel hop

 

[86454K30]

Have you tried putting a different tire and wheel setup? Stock wheel/tire size? What about air pressure changes? Only other thing I might try is maybe bead balance the tires instead of spin balance...just to try.