2011 Vibration at Highway Speed

[jhetcel23]

Hello, having trouble diagnosing a vibration I am getting in my 2011 XLT, 4WD at 65mph+. I can feel the vibration mainly in my seat, but ever so slightly in the steering wheel too. No tracking issues, and no issues when breaking. The truck only has 29,000 miles on it, but the PO had said it sat for awhile. First thing I did was a tire rotation and balance, no change. Tires have good tread, no uneven wear. Since the vibration was in my seat, I focused on the rear end first. I jacked up the rear end and put it in drive, the rear driver side tire did not spin. Even though breaking felt fine, it ended up being a clogged line. Replaced all break components in the rear: lines, rotors, calipers, pads, and parking break shoes. Front breaks looked fine (appeared to have new rotors and pads), and did a complete flush. No change in vibration. Then changed rear axle bearings and seals, no change. Then replaced rear driveshaft u joints, greased the slip yoke, and replaced both yoke flanges as one had broken around where the retainer clip groove is. Again no change in vibration. I then read up on forums and road force balancing was mentioned a few times, so had this done. 2 of 4 tires were way out of spec when the tire shop did the road force balance. So I ordered 4 new falken wildpeak A/T tires, had them installed, and I would say about 50% of the vibration is gone. So looking for suggestions on where to go from here.

 

[19Walt93]

If you have a dial indicator check the driveshaft runout, if not try disconnecting the companion flange from the pinion flange and rotating it 180 degrees. If the vibration changes, turn the flange to another set of bolt holes and drive it again. It may take a few tries to get it to the best spot. Make sure to mark the flanges first so you'll know which position is best. If the vibration is from the rear the steering wheel may shake vertically, if it's from the from the wheel will most likely twitch side to side.

 

[jhetcel23]

If you have a dial indicator check the driveshaft runout, if not try disconnecting the companion flange from the pinion flange and rotating it 180 degrees. If the vibration changes, turn the flange to another set of bolt holes and drive it again. It may take a few tries to get it to the best spot. Make sure to mark the flanges first so you'll know which position is best. If the vibration is from the rear the steering wheel may shake vertically, if it's from the from the wheel will most likely twitch side to side.

thanks for the suggestions, I'll try to get my hands on a dial indicator. Also going to remove front drive shaft and drive to see if that makes a difference.

 

[sgtsandman]

Look for the balancing tabs on the drive shaft too. Make sure they are still there and haven't fell off. If you have a bare spot where a tab used to be, that could be you problem. You'll need to take the drive shaft to a shop to get it re-balanced. The tabs are spot welded on. So, if you have a spot weld or two with no explanation as to why it's.they're there, that's where your tab used to be.

 

[19Walt93]

You can balance a driveshaft with hose clamps if you have the patience. Run it on stands at the vibrations worse speed to see what it feels like. Then mark the driveshaft in 4 places around the shaft, I usually start at the rear of the shaft. Put a clamp on with the screw lined up with number 1 and run it again, turn it 180 degrees and run it, turn it 90 degrees and run it, then turn it 180 degrees and run it. Pick the best spot and you're done. If needed you can slide it a little one way or the other to tune it.