truck is shaking!

i hit 70 - 80 mph and i looked over and my passenger seat is shaking like crazy! like seizure shaking. so i hit up discount tire and he reduced my tire pressure to 35, when they installed it last month they had it at 40, i havent tested it out since he reduced it but does anyone have this problem or has had this problem? im hoping it was just the tire pressure

 

I know that with stock tires, my passenger seat normally shakes at normal speeds, but not too bad.

 

mine shakes between 58-68mph give or take. It did it before my stock wheels too so its not a wheel balancing issue. I wish i knew what it was its quite an obvious shake. Nothing too crazy but I have watch my steering wheel shake a bit and my shifter.

 

Have them rebalanced, maybe you threw a weight.

 

If it's just the passenger seat shaking, perhaps it's loose?

 

x2

 

40? what tires are you running... I run mine between 29-32 psi on BFG AT's.. 265/70/R16.

 

if its ONLY the seat shaking i would say its loose. if you have vibs coming from the steering wheel or floorboard then you should investigate further. but look at the seat first. since you say that was the only thing moving.

 

why not just take it out and test it again? same road, and everything.

 

The passenger seats move a little whenever there is no one in them. However if it is suddenly more pronounced then I would have the balance rechecked, they should be able to do that for no charge.

 

too many to quote but, its not my passanger seat only, eveything in my back seat, steering wheel. im running 285/75/r16 stock rims.

 

oh no, theyre shaking like CRAZY

 

ok...but did it become suddenly worse or just since the tires were done and aired up to 40 psi?

 

your not running bias ply tires are you? stupid question but.......

 

maybe 3 days ago i noticed

 

whats that?

 

I lost the bottom bolt of my shock once and that made my life hell.. check that stuff. Something should be obvious. if it isnt, get them balanced and that'll answer that.

 

I guess you could also have a tire seperating on you. Just have a tire shop check em then go from there. It is just too hard to diagnose over the interwebs like this sorry.

 

Yup. whatever you do, do it quick before you ruin something or kill someone.

 

also if your running alloy wheels are the shop used an impact gun without a torque stick. they could have warped the rim. but like every 1 says its are to diagnose over the web.