New Truck-Weird Bounce

JML79 · March 24, 2005

I bought a new '05 Chevy 1500 Ext. Cab Z-71 last Thursday night which I absolutely love! However, I am noticing a good bit of shaking and bouncing on the highway and I think I may have a tire (or 4!) out of balance. The thing is, the truck has less than 500 miles on it-so is it possible that GM does not balance these tires properly at the factory? (it wouldn't surprise me, but I figured I'd ask to see if anyone else has had this issue)

I had the torsion bars cranked up last weekend and the truck re-aligned at the same time, so I am confident that all is ok as far is that is concerned-the truck tracks perfectly straight with NO vibration in the wheel at all. The shaking and bouncing is evident in the passenger seat, the cupholders, and my stomach at highway speeds though!

Let me know your thoughts-I will likely take it to the dealer tomorrow to have them re-balance all 4 tires and check for any that may be out of round.

Truckman031 · March 24, 2005

I would check the balance of the tires. It could be human error. Congrats on the new truck

dewfpo · March 24, 2005

If it is a tire/balnce problem, swap the wheels front to rear on that side and see if the problem changes, if it does, you know which wheel/tire is bad.

DEWFPO

willieboy · March 24, 2005

I would get your wheels rebalance it only cost 20 bucks. Could be you threw a wheel weight. I did that once, and it about shook me to death...

GM-Tech · March 24, 2005

Could be tires, but our empty pickups are fairly bouncy. They have kind of a rubber band feel to them is the best way I can describe it. They really respond to undulations in the road and cranking up the torsion bars doesn't help.

bigdogxx · March 24, 2005

Could be tires, but our empty pickups are fairly bouncy. They have kind of a rubber band feel to them is the best way I can describe it. They really respond to undulations in the road and cranking up the torsion bars doesn't help.

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I agree i have had far less issues with suspension parts and ride quality when i leave the torsion bars alone and only use them to adjust over time and miles and not crank them 5 turns to raise the front end!I dont care how much the front sags the factory has them set there for a reason and not to get a free lift out of it just my 2 cents.

elvisdog · March 24, 2005

The wheels were out of balance on my 2004 Silverado when I first got it...shook like a wet dog at speeds over 65...has em' balanaced and it is fine now.

JML79 · March 24, 2005

Thanks for the input guys. I am going to the dealer tomorrow morning to get this worked out. I have had trucks with out of round tires and unbalnced tires before-this feels exactly like that.

I cranked the torsion bars up on my '01 when it was new and had absolutely zero ride problems after that, so while I realize that doing this makes the ride a bit stiffer, I don't believe it should be so bouncy and shaky like it is now at highway speeds. We will see what the dealer says.

jwhjr · March 25, 2005

My 04 bounced pretty good for a few months after I got it last spring, but after a few good loads it seemed to smooth out.

2003 LT Tahoe · March 25, 2005

Could be tires, but our empty pickups are fairly bouncy. They have kind of a rubber band feel to them is the best way I can describe it. They really respond to undulations in the road and cranking up the torsion bars doesn't help.

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GM-Tech,

In your opinion are there long term wear and tear problems with cranking up the torsion bars? I.E. reduced shock life, suspension parts etc. How about if a vehicle is equipped with Autoride. Will this cause additional problems? Please advise. Thanks.

GM-Tech · March 25, 2005

In your opinion are there long term wear and tear problems with cranking up the torsion bars? I.E. reduced shock life, suspension parts etc. How about if a vehicle is equipped with Autoride. Will this cause additional problems? Please advise. Thanks.

Done within reason (which is hard to define) I would say no problem.

2003 LT Tahoe · March 25, 2005

In your opinion are there long term wear and tear problems with cranking up the torsion bars? I.E. reduced shock life, suspension parts etc. How about if a vehicle is equipped with Autoride. Will this cause additional problems? Please advise. Thanks.

Done within reason (which is hard to define) I would say no problem.

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Thanks. I appreciate your input!

JML79 · March 28, 2005

Well, I took the new Z-71 in on Friday to have all 4 tires re-balanced and tested to make sure none were out of round. All 4 tires were OK, yet the truck still had a bad bounce that they isolated to the rear end. After removing the rear differential cover, it was evident (from the blue/purple areas) that the axle had been VERY hot, possibly due to some bad bearings or something similar-this would explain the bounce and very low humming noise at highway speeds which I originally thought was one of the tires. The tech said he is surprised that the rear end hadn't locked up on me yet and if I had driven in any longer, it would only be a matter of time before it left me stranded.

I will know more today on exactly what "the fix" for it will be. With only 500 miles on the truck, I hope this is not a sign of what's to come!

hihosilverado · March 28, 2005

With only 500 miles on the truck, I hope this is not a sign of what's to come!

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I would not worry about it, parts can be defective. The rear end is pretty simple and wont be hard for them to fix. If it was a big engine or tranny problem I would feel differently and would fight to get GM to buy it back, but not for the rear end. You might be able to get GM to give you an extended powertrain warranty though--its worth a shot.

JML79 · March 29, 2005

Looks like I will be driving/abusing the rental truck for another week or so. It seems GM mis-diagnosed the problem and it is actually the transfer case that is bad, not the rear end. (turns out the 1st guy who looked at it wasn't even a rear-end tech!) They wanted to put a re-built transfer case in it, needless to say that isn't going to happen with only 500 miles on it, so they're waiting on the new one to come in.

Hihosilverado-that was good point about the extended warranty. I am going to begin laying the groundwork for that now. It's worth a shot at least.