2500HD Shock ????

03GMC2500HD · August 5, 2003

I have a 03 GMC 2500HD with 4600mi on it. Uloaded, it always seemed stiff in the rear like bumps in the road and stuff. Expected though since it is made for towing. The other day it started bouncing real bad in the rear any where from 5-70 mph. Seems like when you hit a bump the rear bounces a couple more times after the bump like the shocks are shot or something. Taking the truck in tomorrow to check the load balance on the tires to eliminate a broken belt but this just started and has me concerned. I know the GM shocks arent the greatest but less than 5k on them and I have never hauled anything with it yet? Anyone else have a problem with the shocks and what did you replace them with? Thanks!

SxViper · August 5, 2003

Well after my brother wore a cup of coffee on our trip to ohio I have started to notice that my truck does bounce a lot. My front is very stiff and bounces a real lot on small little patchs on the road. I noticed this big time on NY state where there was a ton of patches in a row. The back when unload sounds like the leaf springs are slapping together over bumps and it bounces a lot. The bouncing didn't really bother me to much, but my brother just was not ready for that and wore some of his coffee... Boy was he pissed... He does not like trucks to begin with... Of course he drive a nice little Envoy... LOL and he wants to buy a H2 or Surban or Thoe as his next SUV so he can tow... Can't wait till he drives one of those... Better be ready for some bumps... LOL

Is there any way I can cut down roughness of the ride? Doesn't bother me much, but bothers other people in the truck...

f7_ditch_jumper · August 6, 2003

my truck started to get rough in the rear at 14000 miles. I took a look and there was shock oil all over the outside of the shock. Dealer replaced it no problem but it did take 2 weeks for the new shock to come in.

Shaners · August 7, 2003

What air pressure are you running in the rear tires?

N900WM · August 7, 2003

Hey Guys,

This all sounds familiar!

I went with the Roadmaster rear suspension system on mine and it helped a great deal. Big difference and cheap.

Then I went with 285 tires and that helped also.

I have yet to change the shocks but I would like too. Just not sure which one to install.

I ran the Edlebrocks on my F250 and they worked pretty well when they wern't leaking and being replaced.

BDBWTE · August 8, 2003

Welcome to a heavier sprung truck.

03GMC2500HD · August 8, 2003

You guys are totally missing my point. I understand it is a HD truck and there are stiff springs under it that will cause a stiff ride when unloaded, understood, no problem. I am running 285 Yokohama Geolanders for the past 3500 miles. These smoothed most of the harshness from the rear over the dinky 245's that were on it. My bouncing just started this weekend which hits you right in the seat of the pants at any speed but when you hit a bump, road seam ect. the truck will bounce several times for each bump as if there are no shocks on the back.

The truck is at the dealership now getting looked at because I jacked the back up and dropped it in drive to check the wheels/tires for roundness and discovered the right rear wheel wabbles pretty good. The hub and all was wabbling as if the axle is bent. How could I bend a rear axle in a HD only on highway driving? Should find out today what the problem is. Sure rides like the shocks are shot though!

Hacksaw Hilliard · August 8, 2003

How much air are you carrying in the rear tires? When driving unloaded, I only put 50lbs in the rear and 55 up front. That really softens the ride quite a bit over carrying the max air pressure. I also have the airbags in the rear. I keep only about 5-10 lbs of air when unloaded. My truck rides better than my Acura MDX.

Sorry, just read your last post. Guess you've already done the air pressure thing. I hope they find the problem.

BDBWTE · August 8, 2003

Push on the arse end of your truck she should only bounce twice anymore and your shocks are shot. You could pull the shocks off and check to see the resistance the shock has to offer or to see if any hydraulic fluid is or has leaked out.

JimWilson · August 12, 2003

The back when unload sounds like the leaf springs are slapping together over bumps and it bounces a lot.

There's actually a fix for this. The dealer can install rubber "boots" over the ends of the overload springs. I had it done about a year ago and the slapping stopped instantly.

03GMC2500HD · August 12, 2003

Got the truck back from the shop today and the truck rides smooth again. Turns out that the rear axle nut had started working itself loose and just needed to be tightened up. This is what was causing the vibration/bouncing in the rear. Not sure how it would come loose but the truck rides really smooth again. Still going to replace the shocks though. Just need to find the right shocks.