The problem that I've seen is that you can find many parts that are worn but really don't need to be replaced and have nothing to do with your problem. My experience has been that mechanics have no clue at all and have no problem with doing trial and error on your truck at your expense.

 

Took the truck to a spring shop today. Had all springs, bushings, spring hangers, equalizers etc... everything as far as that concerned checked out.

I was looking so forward to finding out what the problem was, but everything checked out fine. Nothing needed to be replaced.

Had the Transmission Support Spring put on, no difference.

Replaced a Steel Wheel on the Steer axle as one looked a little out of round, then had the tire, wheel and brake drum spin balanced and this was not the problem as left side needed no weight, left side only 4 onces.

No Difference?

I thought about getting a used tire and wheel and swapping out with one drive tire at a time and see if this is the problem, what do think?

Could I have a drum on the drives out of round?

I am really at a loss of what to check next as it seems as if everything I or anyone else knows has been checked.

About the only other thing I know would be get a USB Camera and try to find it this way.

Any Suggestions anyone?

 

Any update to your problem?

 

Also, check where the drive shaft goes into the rearend or tranny. Push up and down and check for play in the yoke. Not the u-joint, the yoke coming out of the rear or tranny. I drove an older freightliner that had that problem. It was causing more of a vibration then a bounce though.

 

This may be helpful.

www.tru-bal.com
I had a bad bounce above seventy, tried everything, shocks balancing, etc then found these. Problem solved.

 

1996 W900;
1,188,000 mi.
12,000 front axle
40,000 rears (3.70)
K W 8 bag air suspension
265" wheelbase
Have the same bounce problem for about four years now; temporary fix is to install new steer tires- bounce will appear when tires are close to 50%, and get more severe as thread wear decreases. This hasn't been a big deal for me, as my truck and trailer both have 24.5" tires, and trailer always seems to be ready for the "hand me downs".
In the last couple of years I have, in addition to changing tires, (1) R&R both front wheels, and drums, (2) Centramatic wheel balancers on steer, (3) R&R all shocks, (4)R&R two driveline yokes, all U joints, two driveshaft tubes, and hanger bearing, (5) all motor supports, (6) two front axle alignments, one three axle alignment,

Some of the above mentioned was needed to correct a defect, cracked wheel, U joint vibration, etc., and each time I replace something, I think maybe this will also cure "the dreaded bounce", but not yet.
Would sure like to find the problem though, if for nothing else, maybe a little peace of mind.

Recently replaced the hanger bearing again, four months old, and it fell apart (aftermarket crap!).
Was getting just a hint of the bounce, or was it the HB telling me it was giving up;
anyway, after that repair, no bounce yet. (fingers are crossed!)