jearking when applying and letting off gas pedel

[berniec]

this might sound kind of vuage, but i'm hoping that somebody will have been through this before.

I've got a 2003 Qx4 with 85k on it. It's fine driving around the city, but at highway speeds 55+ when i give the truck some gas it'll jeark to the right a little bit when i first apply the throttle, but is fine as long as I keep my foot on the gas. If i let it off, there is another sideways 'jearking' when i let off- and again it's fine while it coasts regardless of speed. It's just when throttle is first applied, or let up on, that this sudden jearking surfaces. I love the truck, but this really makes me nervous on the highways, i have to plan ahead for letting on or off the gas so I'm not doing it while cornering or it feels like the trucks gonna slide out from under itself when this sudden jeark happens mid-turn.

thanks everyone for any ideas!

[fueler]

sounds like a rear suspension problem, to me. Mine did the same exact thing when one of the rear lower control arm bushings cracked.... but it would also go into violent side-to-side shakes when coasting, and u didnt mention that....

[berniec]

sounds like a rear suspension problem, to me. Mine did the same exact thing when one of the rear lower control arm bushings cracked.... but it would also go into violent side-to-side shakes when coasting, and u didnt mention that....

agreed it seems like something suspension related. But i'm fine coasting, its only when applying or letting off power that it feels like it wants to flip itself over LOL

[fueler]

what i would do is park it, pull the e-brake, get down on your knees under the rear and have a friend rock the QX4 back and forth (both forwards and backwards as well as side to side) and look for any play at either the lower control arms, upper control arms, or the panhard rod.

[Fisherdude]

maybe if one of your rear shocks were completely shot it could cause it to swing and sway when the a** end of the pathy wants to go up and down.