Problem with box truck

Mitch_4

the mounts, and also check the tread for uneven wear indicating an alignment problem.

Wifes van was doing the same thing..she told me after she could't take it anymore. One tire worn past the steel belts, alighment way out. caused a crabbing motion and wore the tire into an oval..at about 50 mph it would smothen out..must have been a harmonic balance point.

anyway good luck
Mitch

Ken C.

This can't be normal!

I drive a 2004 GMC Savanna with a 12-foot box and dual rear wheels. The vehicle, owned by the company I work for, has a 12,000-lb. GVW and 50,000 miles.

The truck has a ride-related problem that is steadily getting worse. The cab bucks (shakes back-and-forth) under nearly all conditions. I don’t think it’s bad shock absorbers, because the truck doesn’t bounce up-and-down excessively.

The problem is baffling me, because the bucking back-and-forth happens on both smooth and bumpy roads; it makes no difference whether I’m accelerating, cruising, coasting in drive or neutral, or if I shut the engine off and let the truck roll. It happens whether I’m turning, going straight, uphill, downhill or level grade. It happens whether the engine is hot or cold. About the only time I don’t feel it bucking is when I’m driving on the highway a steady 55-60 mph.

The bucking seems to be getting worse week by week; sometimes I feel like I’m on the receiving end of “shaken baby syndrome.” This is this first box truck I’ve driven for a plumbing company. The only other box trucks I’ve driven were U-Hauls and other rentals I’ve used for moving, and they didn’t ride this badly, as I recall.

Does anyone have any ideas what might be wrong with this truck?

Bob Sweet

I had similar problems with a box van that was older than yours, turned out to be the body mounts

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Unknown

worn

Worn or broken rear leaf springs... I couldn't see it til they took it off the truck and fell into pieces...

LarryC

bad mounts

I agree with the bad mount(s). The smoothing out at 50 or 60 is the wind pushing the box against the remaining mounts.

Guy_6

me too

I am having a similar problem with my '98 Suburban: It hops after being under a load (ie:hill)for a while. If I back off the throttle it will smooth out. In less than 2 years I have put 2 fuel pumps in, with NO support from GM , locally or otherwise, (so no more GM for me). I recently put it up on a lift, as I believe it to be a mechanical rather than engine issue. All that I did find was a slight bit of play where the rear driveshaft enters the transfer case, which would fit the symptoms.

YOU may also have something as simple as a bad tire-broken belts in the tire give the sensation of a bent axle. Have a tire person feel around the tires for wobbles in the surface.

bob young

trucks & pipes

inform your boss and he will take it to gmc & they can fix it. if you continue to drive in that condition , do you think the problem will get better or go away ? the gmc boys should know more about trucks than we plumbers. we do pipes, they do trucks. you are in the wrong store.