Ok, I have spent the better part of the week looking through threads about vibrations issues. Let me just say that it would be really nice if peps would go back and post what the fix was to there problem once it is resolved. Many of the post were just left unresolved.

On that note I have a 02, 7.3 Limited with 195k on the clock. It has had this problem since I owned it. I have put about 20k on the Ex since I bought it. Right at 70 mph through 75 mph I get a light vibration.

I does not matter what I do, on or off the gas in neutral the vibration is there until I exceed or drop below that speed. The vibration is really annoying on long trips and I feel on edge the whole time waiting for something to break.

Its not strong enough to rattle change or the mirror but is enough that I can feel it and hear it. I had the wife drive and seems like most of it is coming from behind the drivers seat area.

I really dont want to start throwing parts at the problem. The guys at the shop said its a truck and thats what they do. Needless to say I found another place to have work done.

Here is what I have done so fare

New tires (Bridgestone Revos E)
Upper lower ball joints
Balanced front and rear drive shafts
Replaced the front Drive Shaft CV joint - what was not cheap
Lubed the slip joint on rear drive shaft

Ran the truck without the rear shaft and the vibration is almost undetectable but, still there.

I had it up on a lift and checked for play in all the wheels, found drivers side rear to have a little bit of movement. - Could that little bit of play be causing my issue? I am going to take the rear wheel bearing apart this weekend if time permits to investigate that. No leaks on rear axle.

I have not put new u-joints in the drive shaft as the shop said they were fine. Only the front CV joint has been replaced. Should I go ahead and just change the rear u joints out?

Also all fluids have been serviced and no metal shavings on the plug magnets front, rear, tranny, or Transfer case.

I have no lift and suspension is all stock. I want to put a lift on but issue more then likely be compounded with a lift.

Please Help!!!!

 

So it almost went away when you ran it with no rear shaft? That's a big clue right there. I just wouldn't go over 70.......wastes gas anyway and you might get a ticket. Tried other wheels?

 

I have not tried other wheels but did have mine miked out and they are all straight. I also rotate the tires every 4k so if that were it the vibration would change. My comfort zone is above 70, sorry.

 

It has to be the drive shaft since you said it went away without it installed Even though they said it looked good you could you have dry caps on the ones they could not look at. U joints are cheap so it's worth a try.

 

Well, you talked me into it. Having the shop replace the rear drive shaft u joints first thing Monday. $80 is worth the piece of mind and he said will include a free balance after the u joints are in just to make sure its all good. Got all my fingers and toes crossed that it takes care of it.

 

The U-joints would have been the first thing I would have changed with a vibration. Wheels and tires are more of the shake than a vibration.

 

Ya, but it needed tires really bad when I bought it. So I just went ahead a put new ones on. I didn't change tires just because of the vibration. More out of necessity.

 

I have the same thing, I went to a reputable drive shaft shop and he told me that it was something else. But that was from him test driving it and looking at it. I am going back and get him to replace and balance. It's been driving me crazy, mine starts around 65, please don't say drive slower. Have you been on I-95? you would die creeping at 65.

 

Ok,, just gonna throw this out,, my 02 Ex,, 7.3,, wife said she was feeling a vibration,,,, ended up being the flex-plate/flywheel/what ever you want to call it,,, it was cracked.

 

But did it vibrate when you bought it, before the tires?

 

Flexplate or flywheel works. But he said it changed a lot when he removed the rear shaft. Maybe you should get back after you change the joint.

 

Mine changed when I removed driveshaft too, no more vibration. I had my tires road force balanced with no change as well. I even took a wheel/tire from my f250 and move it to each corner with no change. It has to be coming from south of the tranny. I am on the road now, but when I get home in 3 weeks I will take it back to the drive shaft shop.

The guy that owns the shop is a friend of mine and I trust him, he said that drive shaft issues usually clear up over 45 mph or so and he visually inspected the ujoints which are only a few years old anyway that's why I originally eliminated them,

When I removed the driveshaft to run in frontwheel drive, I did notice that the u-joint in the rear was a little stiffer in one direction than the other.so i'm hoping that's the culprit.

Sorry to hijack haha.

 

Good u-joints can be installed incorrectly and cause vibration. If a U-joint is off center by only 1/32" it will cause a vibration. Even with all the snap rings in place the u-joint can still be off to one side. The internal snap rings to give some.

 

Sorry for not getting back sooner, Boy scouts are keeping me really busy. Did it vibrate before the tires were change I cant answer that because I had the dealer change them out before I took delivery. The ones on it were just not safe!

JMATTEWS - Its all good, its nice to know I am not the only one with this issue. LOL Maybe this thread will help out others with the problem as well.

I am also happy that the shop is going to balance it again after the u joints are put in. Its about $100 to have the drive shaft balanced here in MO. The u joints are $80 installed, with the free balancing seems like a sweet deal to me!

I update you all Monday after the new u joints are in.

 

Well, new u joints are in and it got a little worse. We inspected the old u joints and there were signs of needle bearing chatter on the shafts and they were a little dry. So I was not hurting anything by changing the u joints. Shop quoted $350 to replace the slip joint. Its has to be in that drive shaft! So it looks like the money tree is in need of some water!

I will have that slip joint replaced next when I get the money for it. It has to be in that drive shaft. The vibrations feel like there coming from the slip joint area. Errrrr, how hard can it be to find a stupid vibration!