2011 silverado vibration
Feb 20, 2012 | 11:15 AM
#11
The machine will simplify this process into easy steps. The following assembly radial force variation numbers should be used as a guide:
When measuring RFV and match mounting tires perform the following steps.
Measuring Wheel Runout and Assembly Radial Force Variation
Important
The completed worksheet at the end of this bulletin must be attached to the hard copy of the repair order.
- Measure radial force variation and radial runout.
- If a road force/balancing machine is used, record the radial force variation (RFV) on the worksheet at the end of this bulletin. It may be of benefit to have the lowest RFV assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle.
- If a runout/balancing machine is used, record the radial runout of the tire/wheel assemblies on the worksheet at the end of this bulletin. If one or more of the tire/wheel assemblies are more than.040 in (1.02 mm), match mount the tire to the wheel to get below.040 in (1.02 mm). For sensitive customers, readings of 0.030 inch (0.76 mm) or less are preferable, it may also be of benefit to have the lowest runout assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle.
- After match mounting, the tire/wheel assembly must be rebalanced.
If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned. Because tires can sometimes become temporarily flat-spotted, which will affect force variation, it is important that the vehicle be driven at least 16 km (10 mi) prior to measuring. Tire pressure must also be adjusted to the usage pressure on the vehicle's tire placard prior to measuring.
Most GM vehicles will tolerate radial force variation up to these levels. However, some vehicles are more sensitive, and may require lower levels. Also, there are other tire parameters that equipment such as the Hunter GSP9700 cannot measure that may be a factor. In such cases, TAC should be contacted for further instructions.
Important
- When mounting a GM wheel to a wheel balancer/force variation machine, always use the wheel's center pilot hole. This is the primary centering mechanism on all GM wheels; the bolt holes are secondary. Usually a back cone method to the machine should be used. For added accuracy and repeatability, a flange plate should be used to clamp the wheel onto the cone and machine. This system is offered by all balancer manufacturers in GM's dealer program.
- Any type of service equipment that removes tread rubber by grinding, buffing or truing is NOT recommended, and may void the tire warranty. However, tires may have been ground by the tire company as part of their tire manufacturing process. This is a legitimate procedure.
When measuring RFV and match mounting tires perform the following steps.
Measuring Wheel Runout and Assembly Radial Force Variation
Important
The completed worksheet at the end of this bulletin must be attached to the hard copy of the repair order.
- Measure radial force variation and radial runout.
- If a road force/balancing machine is used, record the radial force variation (RFV) on the worksheet at the end of this bulletin. It may be of benefit to have the lowest RFV assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle.
- If a runout/balancing machine is used, record the radial runout of the tire/wheel assemblies on the worksheet at the end of this bulletin. If one or more of the tire/wheel assemblies are more than.040 in (1.02 mm), match mount the tire to the wheel to get below.040 in (1.02 mm). For sensitive customers, readings of 0.030 inch (0.76 mm) or less are preferable, it may also be of benefit to have the lowest runout assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle.
- After match mounting, the tire/wheel assembly must be rebalanced.
If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned. Because tires can sometimes become temporarily flat-spotted, which will affect force variation, it is important that the vehicle be driven at least 16 km (10 mi) prior to measuring. Tire pressure must also be adjusted to the usage pressure on the vehicle's tire placard prior to measuring.
Most GM vehicles will tolerate radial force variation up to these levels. However, some vehicles are more sensitive, and may require lower levels. Also, there are other tire parameters that equipment such as the Hunter GSP9700 cannot measure that may be a factor. In such cases, TAC should be contacted for further instructions.
Important
- When mounting a GM wheel to a wheel balancer/force variation machine, always use the wheel's center pilot hole. This is the primary centering mechanism on all GM wheels; the bolt holes are secondary. Usually a back cone method to the machine should be used. For added accuracy and repeatability, a flange plate should be used to clamp the wheel onto the cone and machine. This system is offered by all balancer manufacturers in GM's dealer program.
- Any type of service equipment that removes tread rubber by grinding, buffing or truing is NOT recommended, and may void the tire warranty. However, tires may have been ground by the tire company as part of their tire manufacturing process. This is a legitimate procedure.
Feb 20, 2012 | 11:42 AM
#12
Have you tried shifting the transmission into neutral when it's vibrating? That can usually help narrow things down as driveline vibrations like steady bearings, U joints or driveshafts only cause issue while under load.
Feb 22, 2012 | 08:15 PM
#13
Got my truck back today
They road forced balanced my tires
Two of my tires had to much runout
So they replace two tires and got all of my readings at .14-.15
Truck drives great (like a truck should)
They road forced balanced my tires
Two of my tires had to much runout
So they replace two tires and got all of my readings at .14-.15
Truck drives great (like a truck should)
Oct 26, 2012 | 07:15 PM
#16
Registered User
Joined: Oct 2012
Posts: 1
Likes: 0
Silverado Vibration
BerryWS6, a friend of mine has the exact same problem with the exact same truck, has had the wheels balanced twice and is still there. The last dealer had told him that it was a normal condition with the factory 20's. Total BS. He's all but ready to get rid of it. Post up your outcome.
Oct 29, 2012 | 11:23 AM
#19
Teching In
Joined: Nov 2010
Posts: 1
Likes: 0
My '12 Sierra Denali crew has the same problem, I haven't had a chance to get to the local dealer. I bought it from a dealer a few hours away and told them to check it after my test drive, I also test drove a 2012 z71 Chevy Silverado extended cab that had the same issue.
