Truck still vibrating

[weo38]

So I have been chasing a vibration problem on my 04 Silverado with little success. I have been back to the tire shop and had them rebalanced only to find out that two of the tires were off balance by about 4 ounces! This seemed to shock the manager even though I had just been in there about a month or two before to have them rebalanced. So I took it to a different shop and had them done for a fourth time. Problem seemed to be better but not good enough to not vibrate the truck. So I replaced all 4 shocks thinking maybe they were worn and giving me some wheel hop. Still did not remedy the problem. So I am at a loss as to what it could be. It still may be the tires but around the same time I got tires I replaced the brakes all the way around, rotors and pads. My point I guess is that I talked with a friend this past weekend and he suggested that maybe one of my rotors were out of balance. He had a guy he knows go through the similar problem I am having and when he put his old rotors on the truck the vibration was gone. It was his rear rotors which housed the ebrake drum as well. Could this be the problem, has anyone heard of this before? Sorry for the long post. Thanks, Will

[doh]

The vibration frequency should tell wether it is a rotor, or U joint/driveshaft problem.

Also does it get worse under braking/acceleration or left or right turns? Is it in the steering wheel or seat?

[Ryan066]

maybe there is something inside the tire.. like a wheel weight... i had that before.. someone balanced the set.. cust didnt come back for a bit... it came back ... i got it... took all the tires to balance em and heard somehting inside the tire. sure enough there was a wheel weight (looks like it was in there for a long time). that would cause it to go off balance .. be able to be rebalanced but the vibration would still be there cause of the weight shifting around in the tire..

id would also check the runout of the hubs. ive seen one that the hub was off balance/bent.. they said it was causing a pulsation but id think that a bent hub would cause a vibration.

also it could be a bent rim..

what i would do if get a set of wheels that will fit on that truck that you know are smooth... and install them and go for a drive .. ifs its still there then u know it has absoulty nothing to do with the wheels/tires/balance.

ive never seen them drum in hat rear rotors causing a vibration.. the only problem i had was with cheap rotors causing a pulsation..

and if the rotors was physically warped/bent then u would feel it Alot in the brake pedal at highway speeds (pulsation/shudder)

[weo38]

The frequency is the worst at about 47 mph. It feels like I'm riding on something egg shaped or out of round. I thought tires, but it makes no difference it's the same even after a tire rotation. It also happens at about 65mph but at a lower frequency. That's why I am thinking it's one or both of the rear rotors. I replaced the ujoints and they were good. I forgot to mention I get the vibration at 47mph even when I slow down to turn or stop. It doesn't seem to do it under hard braking.

[Ryan066]

still sounds like tires... i would do what i said, find someone with a good set of wheels and switch em.. or if u do have the old rotors throw em on and see if it makes a diff... you gotta eliminate what the problem may be to figure it out.

[Triple-X08]

it is your tires.

not a balance issue, big aggressive tread will cause a vibration. and alot of noise.

doesnt matter how new they are.

i would try swapping the wheels and tires with someone who has a truck like yours, and that will tell you. if both sets of tires do it, then its not a tire or rim issue.

[weo38]

I know agressive tread will cause some vibration but the tires on it are Kelly Safari Trex and by no means overly agressive. I had Bridgestone duelers on it oem and the truck drove great. I will try to track down another set of rims and tires and see if it makes a difference.

[Triple-X08]

have you had an alignment

[Old Dood]

Well, I don't know if this will help but, I was having vibration/shimmy in my Buick and it turns out mostly to be a bad tie-rod. Plus I was missing a weight on a wheel but even after fixing that (Wheel weight) it was still shaking the steering wheel enough to bug me...

[weo38]

Yes I had an alignment when I got the tires put on but was going to have it rechecked. The vibration is worse from the cab to the back. But the reason I am feeling more in the back is less weight. I am going to see if I can have it looked at over the weekend.

[Triple-X08]

have you checked your drive shaft for proper balance or maybe a dent in it, or something to alter the balance of it

[weo38]

Well after several hours working on the truck over the weekend here's what I looked at or changed. I changed front and rear diff fluid, switched front tires from side to side and also removed and cleaned the brake pad sliders and pins in the caliper. Took it for a drive and the vibration is gone! It was pulling to the right and after I did this work and it went away as well. Now my question is can a change of rear diff fluid help a vibration possibly caused by a posi rear end maybe "hanging up"? I used Amsoil gear lube and their additive for posi rear ends. I am still going to have the driveshaft checked and the tires radial force balanced just for peace of mind and get a better balance on the tires. Hopefully the vibration is gone for good. I am also going to lube up the rear brake sliders and pins as well(it can't hurt at this point).

[ockgator]

Get ready for the answer straight from the General... called "frame beaming", usually in the HD's, the frame oscillates at roughly 40-50 mph, once out of the speed range it stops. Best way to tell is to put a few hundred pounds of whatever in bed and drive it. There is a bulletin on it but no known cure, some say a rear anti-sway bar will cure it, others say no.

[weo38]

Can anyone post the bulletin ockgator is referring to? It might be some interesting reading hahahaha.

[69Chevy]

Subject: Suspension Vibration Or Frame Beaming At 40-60 MPH (64-80 KM/H) - keywords front rear shake shock spring tire #PIT3009E - (03/20/2007)



Models: 1999-2007 Chevrolet Silverado Classic

1999-2007 GMC Sierra Classic




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This PI is being superseded to update Recommendation/Instructions. Please discard PIT3009D.


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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.


Condition/Concern:
Beam shake vibration is usually felt in the seat and occurring at speeds between 40-50 mph (64 - 80 km/h). Hertz readings using an EVA tool are normally between 8-24 Hz. This condition is most common on extended cab and crew cab models but has also been noted in other models.

Recommendation/Instructions:
The severity of beam shake may vary from vehicle to vehicle. To determine if the concern is beam shake, please perform the following:

Test drive vehicle to confirm the condition. A beam shake condition will usually respond to concrete type pavements more than asphalt, so the vehicle should be driven over both surfaces if possible.
Place 200-500 pounds in the pickup bed between the closed tailgate and the wheel wells. A beaming condition should dissipate.
Note: Tires with excessive Radial Force Variation (RFV) or out-of-roundness can intensify the frame beaming concern. The following radial force variation numbers should be used as a guide:

P-Metric tires (2wd 1500)
12 lbs or less

P-Metric tires (all others)
24 lbs or less

LT-tires
30 lbs or less


If the concern is determined to be beam shake, this is a characteristic of the vehicle and currently no repair attempts should be made. GM Engineering is currently working on reducing this concern for the 1500 Models. There will be no changes made to the 2500 and 3500 models.