I have an 07 classic 2500hd ccsb and just recently upgraded to h2 wheels with 285/70/17 bfgs. The truck was dead smooth and quiet for about the first week and then all hell broke loose and now i have horrendous rear axle hop between 45-50mph and i mean BAD. I didn't lose any weights off the wheels and have since put dynabeads in which were a total waste of money and a PITA to install. What could be causing this? I had the tires all balanced on the hunter road force balancer and all were good and none were out of round. I have to do something with this as it is horrible. When i'm braking, hard or soft it hops like an s.o.b. between those speeds too. PLEASE HELP!

try the factory rims again and see if its gone??...

i'd do that but i dont want the factory rims on it, i'm sure it will still do it anyway. need to find the cause of the problem. has anyone else had this problem?

That might be a good way to find out if the tires or wheels are the problem, don't you think?

try the factory rims again and see if its gone??...
Exactly

as i said, tires and wheels were as close to perfect on the balancer as i've seen... i think the highest one was around 30lbs and none of them were the slightest bit out of round.

When you say classic 07 do you mean 2007? I haven't looked at any of the newer trucks so I don't know the models. If it is an '07 I would put the factory tires back on and take it back to the dealer. It should be covered under warrenty to fix whatever is wrong.

Try the factory wheels to eliminate any drivetrain issues then screw with your H2 rims. Don't buck the system just do it.

30 lbs is max for radial force variation on a gm truck, you should feel that tire on the road with kind of spec.

the machine said 50lbs was.. hmph! well i guess i'll have to see, i have another new bfg mounted on another h2 wheel under the truck i can try that on each side of the rear to see what happens.

Just Guessing here but I think what he is saying is he allready got rid of the stockers? So doing it right is out of the question??

Chuck

I have an 07 classic 2500hd ccsb and just recently upgraded to h2 wheels with 285/70/17 bfgs. The truck was dead smooth and quiet for about the first week and then all hell broke loose and now i have horrendous rear axle hop between 45-50mph and i mean BAD. I didn't lose any weights off the wheels and have since put dynabeads in which were a total waste of money and a PITA to install. What could be causing this? I had the tires all balanced on the hunter road force balancer and all were good and none were out of round. I have to do something with this as it is horrible. When i'm braking, hard or soft it hops like an s.o.b. between those speeds too. PLEASE HELP!
are the wheels hubcentric?jack it up and remove the rear lugs to look for the evil marks that will be there if wheel is not hubcentric.the lugs could also have loosened up and wheels went crazy if not centered to the hub.sounds unsafe,like others said
try the stock wheels.if the one you like are giveing
you the problem,sometimes you have to move on,find a new wheel,one that is made to fit your truck.good luck

If the beads are still in, that could be your problem. Dynabeads do weird things.

Wheels are hubcentric H2 chrome wheels. At first i thought that the dynabeads helped but it has gotten worse.

the truck is lifted
the tire hop would be from frame flex. it is in all crew cab truck

my truck is not lifted.

The tire hop is in not from frame flex. Maybe axle wrap, but not frame flex.

Do a search for "beam shake"


The problem deals with the concrete segments of the road and how their spacing is related to the wheelbase. I assume you have a CC/SB truck? If it smooths out with about 300-400 lbs in the bed then that is your problem. GM has no fix

It does smooth out with tounge weight on hitch. It didnt do it empty for the first 5k miles though. We have no concrete roads around here either. It does it as soon as it hits 45 on any road. :( Yes it is a CC/SB.

That is exactly what is happening to my Truck. Mine has the stock PYO's and 285 Terra Grapplers. Mine does it at like 80-85.

It's when the rear springs sag and ride on the overloads. With that spring weight and the light backend of the truck can make a rough ride

I doubt this is just a "rough ride" that doesn't just appear at 45mph something is wrong take it to the dealer.

It does smooth out with tounge weight on hitch. It didnt do it empty for the first 5k miles though. We have no concrete roads around here either. It does it as soon as it hits 45 on any road. :( Yes it is a CC/SB.


Mine does the same d** thing 45mph drives me crazy!