Vibrations at speed & Three sets of tires in one week..my dilemma
 

Last week I took the Excursion into Discount Tire for some, you guessed it, new tires. That first time I left the store with some Cooper all terrains. The drive home involved plenty of highway driving. By the time I got home I decided to take the tires back because there was terrible vibrations (vibrations is still a problem I'm having) and there was actually sway and whole lot of play in the steering that was very noticeable while just changing lanes.

That was the first set of tires. My second set I got that day were Pirelli STRs, what I had on originally. The dreadful steering was gone but the vibrations persisted. I figured that maybe it was just my luck that I would have had a bad balance job done, so I took it to the local Ford dealership who has one of those nifty Hunter GSP9700 balancers. The vibration improved slightly but was still quite noticeable. I took it back to Discount Tire that same day. They balanced the tires again and told me whoever balanced them before had done a poor job..nice, my luck again. This second balance job got rid of more of the vibrations but it was still not where it was at even with the old tires. The tech actually told me that dealership counterbalanced the tires and that this is counterproductive..is this true? He also had to remount the tires on the rim because it was not centered on the wheel. Two tires were out of spec and messed up as well.

A few days later and after some talks with a regional manager of Discount Tire, I had Michelins new LTX M/S2s put on. These tires definitely are nice. But there's one problem, the damn thing still vibrates...This leads me to my issue.

After three sets of tires, I have a constant vibration that begins at about 65 mph. Am I just cursed with crappy balance jobs? Is it possible that even these Michelin tires are out of round and causing vibrations like the Pirellis? Or is it something with the front suspension that has recently had work done to it?

The front suspension has new driver side ball joints, new front rotors, brake pads, and bearings. I plan to do the passenger side ball joints as well as new shocks all the way around here soon.

I really am at a loss here. And I hope I didn't completely put you to sleep with this long winded post.

Any suggestions would be MUCH appreciated.

how bad is the vibration? is it a up and down or side to side vib

It's not an "OMG, the Excursion is going to rattle itself apart" vibration but it's noticeable enough at highway speeds for it to be uncomfortable for the family. I'd describe it more as an up and down vibration..as if the tires are like a basketball dribbling against the pavement.

I am having the same issue. I thought it was my new tires (balanced and rotated twice). Then I thought it was the front bearings so I replaced them with Timken. Still doing it. I put the truck on jack stands and ran it at the speed that it started to vibrate. Nothing looked out of balance. I am thinking my issue is in the torque converter.

U joints on the driveshaft, maybe?

I wasn't having this problem before the new tires but I'll definitely take a look at those.

I am having the same problem however, I still have the same set of tires. I was also having a pulling issue which I did a post on. I am still getting the vibration like you (around 65) but it depends on what road I am on. I know there have been several posts on this in the past and no one has come up with a good answer to fix this problem.

My vibration is there at all speeds above about 60 or 65 on any road.

I'm hoping that some more people will chime in because I can't find much through search.

I feel for you. I am having the EXACT same problem. This is my wife's car, and I don't drive it all that often. I replaced the sway bar bushings last week, but when we went to VT last weekend and pulling our boat it was horrible. Funny thing is that it would go away when going up hill. I thought it might go away on the way back, since we leave the boat in VT for the season. Not a chance - still shaking. Then the other night, we were looking for a lost dog on the road (not mine) and I hear a squeak at very low speed from the right rear wheel that got faster along with increase in speed up until maybe 15 mph. possibly unrelated. A freind did say that these things need the tie rods and sway bar links replaced around 100k - which I am at. On another forum, I saw something about the need to use a torque wrench ONLY - not an airgun on lugs. I think I remember 100-120 lbs- can someone confirm? I don't have a manual. Yet another mentions an out of balance drive shaft. Yes - this is driving me nuts also. I am doing one thing at a time as process of elimination - starting with front shocks, but the tie rods/links makes sense, and will be next.

Tie rods is something I may be doing. At 180,000 miles it may be time :p

As for the torque spec for the lugs, I want to say I've seen 165 lbs but I'm not completely certain. If someone knows for sure, please share with us.

I've read in another forum RV.net that you should check your rear brake calipers to make sure it's not seized. Drive around and feel the rim. Does one feel hotter than the other? Also, diff. fluid change if it hasn't been done. Make sure the proper amount of additive is added for the limited slip.

When they are balancing the tires have they said anything about your wheels? A slight bend in the wheel will cause vibration at speed similar to being out of balance.

I've thought about that myself. But nobody has mentioned the wheels.

Very interesting. That might explain a lot, and connect the dot with the squeak. I have an infrared thermo so I can get a more accurate reading than, right wheel is "Ouch" hot, left wheel is "OUCH hot"! I'll let you know my readings.

You may also want to make sure your parking brake isn't too tight and engaging on the rotors.