2006 Silverado vibration

[Gagliano7]

I have a 2006 Silverado 1500 reg cab long bed 2WD. I have a vibration around 35-45 mph and 61-72 mph. At 55 mph zero vibration. I took the wheels off my gmc with no vibration and put them on the silverado same vibration. So I know it is not the wheels. I have it narrowed down to driveshaft or axles. Anyone have any suggestions? Thanks

[CamGTP]

With it being 2WD I'd suspect a bad u-joint. Usually those trucks have a long 1 piece aluminum driveshaft, so if something is out, you will feel a vibration.

[richard wysong]

2x check the u-joints

[Gagliano7]

U-joints were replaced no difference.

[richard wysong]

Possibly a rotor threw a weight or bent axle. Can you tell if it is front or rear? I think you would feel it in the brakes if it was an axle though. Any correlation to RPMs? 35-45 could be torque converter but I don't think it would be a factor at higher speeds

Edited April 23 by richard wysong

[CamGTP]

Could check for a missing weight on the driveshaft too.

[Gagliano7]

Rotors are new no change from old rotors. Definitely not the front because i don't feel it in the steering wheel. The only reason i don't think it is an axle is because at some speeds it is smooth as silk and other speed it vibrates. It also does it at a different rpms. I am going to see if i can try a different driveshaft to see if that is the fix. My driveshaft is aluminum and looks good nothing i can tell that is wrong.

[Gagliano7]

Replaced driveshaft with a steel one. Old one was aluminum. Vibration is gone up to 65 mph. Went on the highway today as i hit 70 a terrible vibration back below 70 smooth as silk. Old drive shaft vibrated in the 30 to 45 mph range god until 58 mph. From 58 mph until about 68 mph vibration but once i was above 68 mph no more vibration. The vibration on old driveshaft was annoying but not extreme. The new driveshaft above 70 mph is extreme feels like something is going to break. I am returning new driveshaft and they are going to send me a replacement but i am not feeling to confident now.

[richard wysong]

sounds like you are on the right track, the new 1 probably wasn't balanced properly

[Gagliano7]

Well I changed the driveshaft to a steel one. The vibration is way less but it still happens. The range is less but it is still there at certain speeds. Not sure where else to check. Anyone one have ideas? Thanks I also changed my transmission mount.

[CamGTP]

I think it's time to measure your driveline angles.

 

Measure what angle the transmission is pointing down, the driveshaft angle and what the rear diff is point up. Ideally you want the two opposite measurements to be equally opposite. So like transmission down at -4 degrees and the diff going up at 4 degrees. Being 1ish degree off shouldn't be an issue most of the time.

 

Past that you will be looking at the rear diff itself. Like a possible bearing issue inside it.

[Gagliano7]

On 6/3/2023 at 4:36 PM, CamGTP said:

I think it's time to measure your driveline angles.

 

Measure what angle the transmission is pointing down, the driveshaft angle and what the rear diff is point up. Ideally you want the two opposite measurements to be equally opposite. So like transmission down at -4 degrees and the diff going up at 4 degrees. Being 1ish degree off shouldn't be an issue most of the time.

 

Past that you will be looking at the rear diff itself. Like a possible bearing issue inside it.

the truck is all stock so i doubt the driveline angles are incorrect but i will check.  I did put a posi unit in and 4:10 gears. All new bearings and and pinion and gears set to spec. I never drove it on the highway with the stock gears so i don't know if it had that vibration before. I would think a gear or bearing problem would be all the time not at certain speeds. It could also be the axles or maybe my brake drums are out of balance. I have a brand new F150 and i like driving my very plain Jane reg cab long bed silverado more. 

[Gagliano7]

Checked pinion angle and it is spot on.

[Gagliano7]

Found the problem. It ended up being my wheels and tires out of balance plus my driveshaft out of balance. 

[Gagliano7]

Just wanted to let you know people in the southern NY area and mid to northern NJ area Axle Exchange in Fairfield NJ  balanced my driveshaft. They will also make you a driveshaft.