Need some advice on this one. 2003 C-15 W900L Daycab. I have a jerk in my Truck that goes from side to side when the speed is 40 to 45 and 66 to 69 mph. Otherwise it is a smooth ride.

I have noticed that it does it much more when empty than loaded. I can notice it when loaded, but nothing like when I am empty?

I have had trucks that had bounces in them, but never a jerk from side to side (left to right, and right to left)

I had this in it prior to my wreck an everything was checked and fixed from the wreck, but it is getting worse.

Kingpins replaced after the wreck, no change

3 axle alignment done after wreck, no change

I replaced the steer tires, had them spin balanced on the drum and nothing changed.

Replaced the drive tires and nothing changed.

Had suspension updated 18,000 miles back, no change.

Front shocks replaced 75,000 miles back

Rear shocks replaced 45,000 back

My truck has 859,000, so started replacing items as needed, but nothing has caused it to get any better, or worse.

Could it be cause by a bad brake drum? No reason to think this just thinking out loud?

Or maybe the shock on the back of the cab, or thrust bushing (this is what I call it) that goes from left to right behind the air bags and shock on rear of my cab.

Thought maybe my tires would start to show some funny tire wear as I have 10,000 on them, but nothing yet?

Any advice for me to check would be so appreciated.

 

Papa Rick I know you said you had a 3 axle done on your truck but if I were you I would spend some time with a couple tape measures, a string and a buddy.

Your drives need to be square to the frame, parrallel with each other, centered with the frame, the same distance from steer to front drive from side to side.

Mike

 

You need a 400 pound APU to counteract the side to side action.

 

Done did the string, tape and buddy and found nothing out of measure. I thought for sure by now if it was something like that or anything that I don't know to check it would have showed up on my tires by now????

Really at a loss of what to check for.

 

Motor mounts?

 

Replace the steering wheel with one that doesn't jerk from side to side. :lol:


All kidding aside, given the fact that you've already checked or replaced everything else, I would look at the steering - specifically the steering box. Perhaps if there is too much free play in it, you are noticing it at certain speeds. After all - you've already replaced everything else. Why not the steering too?

 

Truck jerks from side to side badly until you`re empty?
That is to say until you have "unloaded"? :lol: :lol:
Would there be a box of Kleenex in the cab at the time? :lol:








Sorry ops:

 

If you have the AG 200 rear suspension, the bushings between the rears are probably worn out.

AG 200 was famous for this and there have been several fixes over the years, check with KW and find out how to check the bushings and what to look for.

AG 200 is the one with the 1" air lines that go thru the frame from inside to the bags.

 

Going to see if the KW place in Chattanooga can look at it tommorow. As for the suspension, I had it updated and all bushings that should be replaced done 18,000 miles ago.

When this started I thought it was cause the tires were getting wore out and it would go away when I replaced them, but it has not.

Really it seems to be getting worse as times go by.

 

Or transmission mounts? Or like rev said steering box valve.