I am hoping someone can help point me in the right direction on this issue I am having.

When driving and crawling in traffic around 10-20mph my truck rocks back and forth quite abit and the faster I go the quicker it rocks. I can feel the rocking/shaking up until i hit about 65-70mph and then it goes away. I have had the balance of my tires checked and they are balanced. I have had the alignment done. and then just recently when I had the truck at the dealership, they replaced the front left U-joint, the right ball joints, and then that was when they also did the alignment.

I have crawled under neither the truck and grabbed everything i could get my hands on and pulled on it to see if anything was loose and couldn't find anything.

Any ideas?

Thanks,
Steve

 

Rockin truckeh .... reminds me of my highschool prom date



Have you tried rotating the tires yet?

 

Maybe someone pulled yer seat out and tossed in granma's rockin chair?

I would check seat mounting, I know mine (with power seats) will slide every so much back and forth (worn tracks?)[:@]
Dare I say?Check cab mounts...loose maybe?

 

Hey Mayfair, I wouldn't have an issue if that was the only time it rocked, but its not, lol.

I have already rotated the tires, i just forgot to mention that. I had them rotated and the alignment done at the same time.

The rocking is from side to side so its not the seat, as i know the movement you are talking about. Mine moves forward and backward about 1/8 of an inch when i stop quickly, and i have checked for side to side movement in the seat. I have the power seats as well.

I went for a drive and kept a close watch on it and when it rocks the whole cab and bed moves side to side together, so i dont' think it would be the cab mounts, but i am still going to check those.

Thanks for the ideas guys. I will let you know what i find when i crawl back under it to look, should hopefully be a little later this afternoon. If you come up with any other ideas let me know.

Thanks,
Steve

 

Tires? What load range are they? Weak sidewalls, maybe?

 

just got back in from crawling under the truck again and still couldn't find anything that needed tightening. One thing that i did notice is that at the ends of my leaf springs the different leafs aren't aligned, i don't know if they are suppose to be or not, i grabbed them but they don't move either. I also lifted the truck up and down so i could see when the suspension moved if the leafs would and the alignment on them doesn't change.

The tires are Interco TrXus MTs. Below is what their site lists as the details for the tires.

Prod Code: RXM-13R
Size: 33x12.50R17LT
Weight: 71
Ply Rating: 10
Sidewall Ply: 2
Skid Depth: 19/32
Tread Width: 9.60
O.D.: 33.2
C.S.: 12.3
Rev Per Mile: 673
Rim: 17x8.5-11
Max Infla.: 65
Max Load: 3085

I have checked my tire pressure and all of the tires are running 52lbs right now.

 

I don't think it would be the tires since they are 10 ply.

 

I would air up those tires to 60-65psi (the max) 2ply sidewall - D rating? Airing up the tires will net you some mpgs as well.

 

Thats a good idea on airing up the tires, i will do that tomorrow. I don't know the actual load rating letter designation but they are rated at 3085lbs each for max load. Are the letter load rating designations based on a certain weight range, or do they mean something else?