Truck makes some weird stuff when turning

[jayman3]

I use my 03 350 to haul my backhoe around and ever since i installed air bags in the rear,it makes this kind of shifting of the rear of the truck,could it be my rear end taling a shit or something else,it won't do it on gravel only on pavement and only when loaded.

[mitchbtu]

It could be there is more sway with the airbag suspension, especially under load.... It wont do it on gravel as there is more road give, and the traction isnt as good as on pavement... My 2 cents worth to maybe help identify the cause...

[Smokeispower]

If you used those bolt on "ears" for the top of the bag, check to see that they are secure to the frame - one could be loose and shifting under side load.

[jayman3]

Thanks for the quick replies,Smokie what do you mean by ears.The next time I pull the backhoe I will try it with no air in the bags.

[Smokeispower]

I guess it depends on the bags you have. The upper mount is usually bolted to the outside of the frame, I call those "ears". If they are not tight and snug to the frame, the side load from the trailer will make them move around. Good idea to try without air in the bags, that will tell you where to go next.

[jayman3]

I have the firestone bags,yes they are mounted on the outside of the frame,will check that out.It almost feels like it is trying to stay locked then it comes out then in again.

[Smokeispower]

Do you notice it more when on the gas or coasting?

[jayman3]

I notice it when I am on the fuel it only does it at low speeds .

[Smokeispower]

Did you change anything else, like tires? Have you checked tire pressures to see that both rears are the same?

[Phil G.]

If you think it is coming from the actual rear axle and if you have positraction, at the minimum, I would add a bottle of friction modifer. Better yet for added isurance, I would change the rear axle oil and add 2 bottles. Changing the fluid will give you a chance to inspect the crown & pinion as well.