Bouncing 2001 GMC issues

biscuit · Feb 24, 2012

I have a 2001 GMC 1500hd. I have set of aftermarket eagle alloy wheels 16x8 I think. I am running a BF goodrich 285/75/16 AT. When I am runnig around town at about 45-50mph the truck has a bad hope to it. You can slow down or speed throught it and it will quit. I have had three other sets of diffrent tries and it does the same thing. I have had tires trued in the past and it still does it. I have had the tries rebalanced and still nothing. I had some one tell me that it is the after market wheel and if I would change back to a stock wheel it would not do it. I do not belive them nor do I have set of factory wheels. I know of three other friends that have the same issue. Just wanted to see if anyone of you have heard about this and is there a fix for it.

onetoncrawler · Feb 24, 2012

http://www.dieselplace.com/forum/showthread.php?t=272124

common problem, I noticed it on my old HD, got new tires and it would still do it every now and then even after road force balancing

I dont know a fix?

leeman1790 · Feb 24, 2012

I notice this too in my truck, 05 hd crewcab diesel. I never really noticed it my first 2 sets of tires, the km2's were pretty much square and the cooper ST's feathered bad very quick. Then I bought some new rims and nitto highway terrains. They are smooth as glass and I notice it bounces some around 40-50. I just thought it was the HD ride or wavy pavement. Might have to talk to my service writer and see what he says.

s10me · Feb 24, 2012

I have an o4 4 door short bed 2500hd that didn't do it with the fatory tires but has done it thru three or four different tires, sizes, and wheels?

whiskeymakin · Feb 24, 2012

just about any vehicle i have had with aftermarket wheels or just oversized tires had a hop in it around 45. just a bad speed i guess :wtflol:

Speeding · Feb 24, 2012

Aftermarket wheels, 35" BFG ats no hop but bad vibes above 30. now on 33" Trail Grapplers and smooth as glass at everything but 43mph. "bounces" just like you said. Figured it was just a bad balance job and never worried about it.

Weird.

leeman1790 · Feb 25, 2012

Speeding said:
Aftermarket wheels, 35" BFG ats no hop but bad vibes above 30. now on 33" Trail Grapplers and smooth as glass at everything but 43mph. "bounces" just like you said. Figured it was just a bad balance job and never worried about it.

Weird.

Bad balance job from Brian not possible.

Speeding · Feb 25, 2012

leeman1790 said:
Bad balance job from Brian not possible.

bad balance more like out of round tire. should have ponied up for the road force testing.

Scott T. · Feb 25, 2012

GM redesigned the rear cab mounts to stop a bounce on the HD's.

xjkrawler · Feb 26, 2012

PrairieDogOffroad said:
GM redesigned the rear cab mounts to stop a bounce on the HD's.

this..... its the rear cab mounts and front bed mounts.

if you put alot of weight in the front of your bed and it goes away then its the body mounts.

there is an upgrade to keep it from happening. i think it stiffens the frame or something to keep it from twisting.

doctordick · Feb 26, 2012

Flexy frames have always been an issue with GM pickups. Back in the 70s we used to break those Chevys in half right behind the cab in the oil patch. Get behind an 80s or 90s Chevy and you'll see the left rear corner of the bed hiked up from frame twist. Too bad you can't buy a GM drivetrain in a Ford chassis, never broke or even tweaked a Ford. Maybe that's why the Fords don't ride quite as nice as a GM :dunno:

Cherokee Johnny · Feb 26, 2012

It is true about the twist in the rear frame. Its from when they chained them down to transport them from the factory. The dealerships used to fix them by shimming up the other side of the bed.

zukiscott · Feb 27, 2012

HAH...HA HA, I don,t know if you will get it fixed in time or not :dunno:

But what I DO know is that you better be ready to HOPPITY HOP HOP that sumbitch to Evarts in a few weeks :****:

:flipoff1:

biscuit · Feb 27, 2012

zukiscott said:
HAH...HA HA, I don,t know if you will get it fixed in time or not

But what I DO know is that you better be ready to HOPPITY HOP HOP that sumbitch to Evarts in a few weeks :****:

Don't you worry. I am ready. It does not matter if rode like a jack hammer I will be in Evarts rip roar'n and ready to wheel.

I think I will try the weight thing in the front of the bed to see if it goes away or helps.