truck sways alot, tires fault?

[blazin8556]

i have a 96 chevy z71. got procomp extreme wheels or something like that, 33x10.50 maxxis big horns, 3 inch body lift, and air shocks in the back (around 20 psi). unloaded im noticing sway in the back end of the truck bad enough that youll wonder if youll keep control of the truck(worse around 70). loaded (utility trailer and a s10 or minivan or something) it feels the exact same but lower speed, as i take back roads and go slow to keep from overworking the systems. i know there is a load and expect sway, but unloaded there should not be much. what is the pressures you guys are running on your tires and air shocks if you have em.

[cancritter]

weak sidewalls....lotta folks with large tires that haul or tow will run into this issue...

[blazin8556]

Even unloaded?

[TheBigMortboski]

Yeah. Did you get them siped? If so, that'll make it even worse. What's the ply rating? And those big lug tires aren't ideal for towing anyway (or driving on roads, for that matter).

[blazin8556]

what is siped. i just had 2 new ones put on the rear at gateway tire and they pulled the older ones to the front after rebalancing them with stick on weights.

[blazin8556]

max tire pressure on these tires is 35 psi. gateway tire had them at 40. let air out of the tires and some from the rear shocks and now it seems to be a lot better.

[Quyonmob]

35psi max on the sidewall implies a C load tire. 33x10.50 (if on a 15" wheel) don't have all that heavy a load rating.

Spring eye bushings can get loose/worn over time too, this lets the axle wiggle, and makes sway show up quite readily.

[blazin8556]

just crawled under the truck to look around. there is only a dime thickness of shiny on the bolts for the front of the leafs and one of the shackles is the same. looks like both of the front of the springs is angled toward the center of the truck. i don't know what kinda tolerances i should be looking at here. im also fighting power steering pump issues. the first one leaked like crazy and the donor pump from my tahoe i hauled off works fine till i drive a while then it roars and gets hard to turn going slow. i was starting to think that the pump was the rest of the problem.

as far as the tires go, i have hauled 3 vehilces in two weeks. this is kinda why i needed a truck (coming out of a 97 v8 explorer) first car was the tahoe i hauled off, second was a dodge caravan through memphis (brakes seemed to be a problem here) next was a s10. they seems to pull ok. other than the sway

[Quyonmob]

You are car hauling on C rated tires and are wondering why there is sway?

Sidewall deflection of an overloaded tire.

[blazin8556]

I know why it sways loaded. My concern was unloaded

[Quyonmob]

I know why it sways loaded. My concern was unloaded

Alrighty then.

[Chevy53]

You might need to install a steering damper, I think you have what they call in the jeep world which is "death wobble"

[blazin8556]

Unloaded- truck only, no trailor or anything in the bed. Loaded- car on 16 ft utility trailor truck tool box full of tools and 4 people in the cab

[Quyonmob]

You might need to install a steering damper, I think you have what they call in the jeep world which is "death wobble"

No. Death wobble is a not an IFS issue, solid axle only. And a steering damper is the wrong bandiad for death wobble anyhow.

[99FLtahoe]

i would go with it being a worn spring bushing and unlikely but rear sway bar end link bushing <--- just did because my tahoe had mild case and tracked it down to lower bushing of rear end link was GONE.

[JIMJOM]

weak sidewalls....lotta folks with large tires that haul or tow will run into this issue...

+1