4.0 4 wheel drive. I've owned the truck for a little over a year and it's always had the vibration, just a little worse now. Took truck back to dealer and they repositioned the drive shaft but didn't help.

I can feel the vib in my seat going down the road. It starts about 62mph. Can't feel anything in the steering. When I let off the gas I can still feel it in the seat but not as bad. Had the tires rebalanced about 3 weeks ago with no change.

 

well theres a few options. bad shock, U joint, bent axle, out of round tire, bent rim.

just cause you had the tires balanced doesn't mean they are true and straight.

 

lol straight wheels are bad, only seen it once, and that car was never gonna run again ever.
they should be round

 

Just checked the U-joints and they seem tight and in good condition. Going tomorrow to have the tires rebalanced. Going to ask them if I can start the the truck and check the drive shaft in gear while it's on the rack.

Not sure where to go if that does solve the problem. I did notice oil is starting to seep from the yoke seal on the rear end, not wet and dripping just starting to coat the front part of the housing.

 

I want to change the gear oil in the rear end. Is Lucas SAE 75W-90 Synthetic Gear Oil replacement?

 

80w90. have the tires road forced as well as balanced. My guess its a bent wheel

 

Got new grease in the rearend.

This thing is driving me nuts. Vibrates in the seat at 62mph. At 67mph move to my feet and nothing in the seat.

Calling Monday to get the tires road force bal. What am I looking at cost wise to have this done?

 

I think it might be $10 more than a normal balance per tire. I'm not 100% sure because I get my balancing and alignments for free

 

Thanks 99

 

Just curious, why won't a regular bal. pickup on a out of round tire or wheel? What makes road forced bal. ant better?

 

I'm sure that you've felt an out-of-balance wheel/tire before and know what that feels like. A driveshaft balance problem is at about 4 times higher frequency than wheel balance so it feels quite different.

I had my original driveshaft warrantied because it would start to vibrate around 65 MPH and became bad enough to blur the mirror above 75. The replacement shaft wasn't perfect but it moved the onset of the vibration up to 80+.

 

I certainly do not want to jump the gun here, so the verdict is still out. I was reading all I could find on tire/driveshaft vibrations and was pretty convinced I needed my tire road force balanced, and still might. But I read something about the exhaust system being loose and causing the vibration at 62 mph.

Got home today and crawled under the truck to inspect and sure enough my tailpipe rubber hanger had a lot of play in it....a lot. So, before I left for a meeting I had tonight I got some heavy wire and secured it the bracket coming off the frame very tightly.

Going to and from the meeting (about 8 interstate miles both ways) I had almost no vibration that i could feel. I'll know for sure tomorrow driving the truck to and from work and report back. Got my fingers crossed.

 

Any update on this? I've been having similar trouble with my truck. I noticed this thread and checked the exhaust, which was loose, but I got that tightened up and had no change in the vibration. I just had the tires rebalanced, but I think i'll have them road force balanced this week to see if that helps.

 

I know this is an old post but I was curious: was any resolution to the vibration issues that you were having?

 

No...still wrestling it. Comes and goes now. Pretty sure it's the tires.

 

I changed out my front and rear axle fluids with mobil 1 which is supposed to have the limited slip additive already in it but soon noticed a "shudder" when I'd take off from a stop, especially around corners. I added some Motorcraft LS additive to them and it went away pretty quick. I'm sure thats not whats going on with yours but food for thought. I'd guess that you have a bad tire.

 

Go after the rims and tires to cure this issue, use the spare tire to rotate with the original mounted tires. I was able to solve my vibration problem when tire was off the vehicle. Turned out to be a bent rim, did not see it while until I knew what I was looking for. Try lifting the wheel off the ground so that it turns freely, place a screw driver tip next to the rim, spin the tire and see if the rim walks in and out in relation to the screw driver blade. Bent rim or bad tires was my issue with vibration.