Vibration @ 50 MPH

[Mike McLaughlin 3]

I've got a overall vibration when I hit 50 mph. I've seen similar post that usually result in more questions than answers. I bought my 2003 XLT in 2010. At the time I bought it I had Moog bushing put in the front end and 4 new shocks. I did this in order to haul small 2000 lb camper. This past summer, the truck developed a high speed vibration as soon as I hit 50 mph. It smooths out somewhat at 60 mph. At the time the vibration started, I had newer tires that had about 1000 miles on them. Since, I've had them rebalanced and had it into my mechanic several times. I came out with a new driveshaft. But, I still have the vibration. I can't tell if it's front or rear as it's not predominantly felt in either the steering or the seat. Just an overall vibration, similar to running over the highway edge grooves, just not as loud.

Like my truck but getting annoyed with the vibration.

 

[Taylor Corn]

Confirm wheels are balanced with another source. Which driveshaft was replaced? High speed vibration like that affecting the whole cab is the front driveshaft in my experience. The propeller shaft bearing design fails and introduces slop into the movement.

 

[Mike McLaughlin 3]

Main rear drive shaft was replaced. Thanks for the tip. It's due into the shop soon. I'll have them take a look.

 

[EddieS'04]

Mike,

The upgraded driveshaft is aluminum. Some tracs had trouble with the steel version.

In '04 and '05 all tracs had the aluminum one.

 

[swshawaii]

Drive shaft unlikely the issue since the OP's vibration occurs at 50 MPH, and his drive shaft was hopefully replaced with the revised part. Here's the TSB:

 

[Mike McLaughlin 3]

Rear shaft was replaced in total about 3 months ago. No affect on vibration.

To diagnose this, is removing the front drive shaft completely a possible alternative? Just temporarily till I can drive it to 50 mph and see if vibration is present with front shaft removed.

My mechanic originally thought the rear U-joint was the issue. It was replaced but the vibration continued so he replaced the entire rear shaft. Still vibrated. Stands to reason that if the front shaft u-joint is bad or worn it could vibrate as well??

 

[Yardsale]

There are two vibration charts in my "Vibration Chart" folder of my library.



I'd be asking for (at least some) money back on that new drive shaft that didn't fix the problem (I call this sort of parts roulette "on the job training"). When I took mine in for a vibration problem, they put a known good drive shaft in for testing.



Yes, the front (or rear) drive shafts can be removed to test. I agree and think the problem is not drive shaft related. Keep in mind that the front drive shaft is always turning (is driven by the front wheels when 4WD is not engaged). Also, The front drive shaft front joint is a U-joint; the rear is a CV-joint.

 

[Richard L]

The basic rule of thumb for determining the cause of vibrations is:



Vibrations that start below 70 MPH are most likely caused by wheel, tire issues. That can mean that the wheel/tire are out of balance, the wheel is bent or the tire is defective. (defective belt, defective tread, etc)



Tires that are out of round can be perfectly balanced, but will still cause vibration.



If the vibration is in the steering wheel, the problems is with one of the front wheels/tires. If the steering wheel does not vibrate, but you feel the vibration in the seat of your pants, the problem is with the rear wheels/tires.



To isolate which wheel/tire is the cause of the vibration, try switching front wheel/tire with rear wheel/tire (one at a time) and see if the vibration moves front or back.



If the vibration starts at speeds above 65-70 mph, then it is probably driveline related to a dented, bent or defective drive shaft. The reason that driveline problems do not appear at lower speeds is because the rotating parts are smaller in diameter, and require higher rotational speeds to cause any vibration.



Some early Sport Tracs had problems with the excessive vibrations with the standard steel drive shafts and Ford was switching them out for aluminum drive shafts to eliminate the vibration issues...but only if the vibration started at 65-70 MPH or above. I doubt that Ford will change your drive shafts now without charging you an arm and a leg, so I recommend checking all wheel/tire problems first.



...Rich

 

[Taylor Corn]

You can absolutely remove the front shaft, and easily on your own with basic tools, to confirm the problem. If you look under, and see a torn boot on the transfer case end, then you can assume that's the problem.



My front shaft bearing went from "could feel" to "could feel" over night, and at around 60MPH for me. It clearly had evolved over the years after the boot was torn and just went un noticed., so one day it will just rear it's head. 50MPH I'd take a look at the prop shaft bearing, and just pop it out to confirm.

 

[RON LAPOINTE]

You could move the front tires to the rear and rears to the front and see if the vibration moves or changes, as this is free if you can do it your self.

 

[Mike McLaughlin 3]

Thanks group for all the suggestions. Scheduled to go into my mechanic next week. We'll start with removing the front drive shaft. If still present, on to the tires and rims.

I'll let you know what is found.

I'd remove the front shaft myself as it looks pretty straight forward but don't really have a good place.. garage is cold this time of year in Ohio.