Random vibration at 42-48mph

[Aspen03]

A couple months ago my 03 EB developed vibration at certain speeds. I chalked it up to a possibly out of balance tire or bent rim (haven't hit anything on quite awhile but you never know). Well here we are at just a tick over 240k and having just had new michelins mounted and balanced about 400mi ago and according to the tech who installed them no obvious defects in any of the wheels. Vibration did not change after tire install.

The vibration only persists while driving between about 42-49mph according to GPS. As speed goes up so does the intensity to where it is enough to cause my rearview mirror to vibrate and distort the image quite a bit. It can be felt in the wheel, floor, etc. As soon as you clear the speed range it's gone.

I have crawled under and done a basic visual inspection and see nothing obviously bent, broken, or loose, or leaking. Front calipers, brake hoses, rotors, and pads are new as of this past fall. Rear rotors and pads about 12k ago. All were done at the same time but a failed caliper up front cracked a rotor and trashed the pad so I replaced the front components in September.

Alignment is spot on with no play in the wheel, it tracks more or less perfectly straight. Road does not make a difference. Hwy, surface street or county road feel the same. 4wd functions as it should and no check engine lights present. The only maintenance I would have upcoming is an oil change in about 1500mi and possibly plugs this spring...They're going on 65k, rear diff service interval and that's about it. I don't tow regularly....maybe 5 times in 3 years and nothing over about 4k and less than 100mi. 85-90% of the milage I've racked up is hwy, unloaded, with just me cruising at 68-70mph. I change fuel and air filter each spring at about the 12k mark and exclusively run Shell fuel generally bought at the same station and pump.

It was meticulously maintained by the previous owner up until the 205k when I took ownership about 3 years ago and I have kept up w a similar maintenance schedule being it obviously worked well for him and now me up until just now. The vibration isn't immediately concerning but eventually it provably will be and I would like to chase this down sooner than later. Weather sucks at the moment so any further diagnostics on my end will likely have to wait a few days.

Any ideas or good things to check that haven't been mentioned?

 

[Motorcity muscle]

Are you still using the older tire pressure monitors? The ones with the band clamp.

 

[Trainmaster]

Check your universal joints at that mileage.

 

[Fastcar]

Vibrations can be a pia. Do you feel in the seat? Its rotational from the sound of it. I'd be looking at a rotor if your wheels are good. Is it 4x4?

 

[Aspen03]

Sensors were just replaced with new ones, not band style and the vibration was there prior to the tires being replaced on the 8th. They are Dill? 7003's that costco had on hand. I had 2 bad so I had then replace all tpms sensors. I wasn't going to do them but the light and alert annoys me...and I drive 55mi a day so it's not a bad idea to have them.

Reading a bit more today I began to wonder about u joint. This is the first "truck" I've personally owned. No experience with what one that is worn or failing is like. Do they tend to act up at certain speeds or loads? It doesn't seem to make much difference if I'm at lpw or moderate throttle, as I pass through that particular speed it occurs, just the duration is longer if I'm accelerating slower.

It is 4x4, I agree something that is rotating just not sure what. Rotors only have a few thousand miles on them, no hard stops on this set and the brakes are velvety smooth when stopping. No noise or pulsation whatsoever in the pedal. It can be felt throughout the truck so yes, in the seat but not localized there. Being the wheels are original I doubt they are perfect but according to the tire tech he didn't see any obvious signs of damage that might cause it.

 

[Yupster Dog]

The vibration only persists while driving between about 42-49mph

Evidently this is a common thing. When I had it on my 02 EB I took it to my friend who works at a dealership service dept.

Got a transmission service ($250) fluid and filter change and fluid change on transfer case.
Sent me home still with the shudder and told me it would go away after 100 miles or so and it did with no problem since.
Another member had the same and after the fluid change theirs was better also.

Here's the thread.
https://www.expeditionforum.com/threads/odd-running-gear-noise.48401/

 

[Fastcar]

Sensors were just replaced with new ones, not band style and the vibration was there prior to the tires being replaced on the 8th. They are Dill? 7003's that costco had on hand. I had 2 bad so I had then replace all tpms sensors. I wasn't going to do them but the light and alert annoys me...and I drive 55mi a day so it's not a bad idea to have them.

Reading a bit more today I began to wonder about u joint. This is the first "truck" I've personally owned. No experience with what one that is worn or failing is like. Do they tend to act up at certain speeds or loads? It doesn't seem to make much difference if I'm at lpw or moderate throttle, as I pass through that particular speed it occurs, just the duration is longer if I'm accelerating slower.

It is 4x4, I agree something that is rotating just not sure what. Rotors only have a few thousand miles on them, no hard stops on this set and the brakes are velvety smooth when stopping. No noise or pulsation whatsoever in the pedal. It can be felt throughout the truck so yes, in the seat but not localized there. Being the wheels are original I doubt they are perfect but according to the tire tech he didn't see any obvious signs of damage that might cause it.

Just a thought. See what rpm it starts at, put it into 4 wheel low and bring it to that rpm. See how that effects the vibration.

 

[Lee_H]

The answer of checking universal joints may be your answer. I just replaced the passenger side front (4wd) cv joint shaft (wrestling experience would be helpful, the shaft does not want to come out). When turning I would feel something pulling like a warped rotor. About a month ago I went on a highway and had the whole passenger side shaking with the steering wheel doing the same. I slowed down and got off the highway OK. Drove home slow and was OK, no shaking. Looked underneath and was reminded that the boot by the passenger front wheel is torn up. I saw some damage before and felt I could do little but add some grease. Ordered though RockAuto a middle-of-the-road priced shaft and finished replacing it this Sunday. Made a short test drive on a local highway and was smooth again. The front wheels are locked in 4wd, vacuum will not disengage the hubs. Bad gas mileage but the differential is well lubricated.

 

[whtbronco]

I played hell recently locating a vibration, at about 250k miles. I swapped the read driveshaft u-joints again, helped a little maybe. They only had like 20k miles on 'em. Anyway, it turned out to be the inner CV joints in the axles. It took my wife flipping between reverse and drive with me under it to see/feel the slight rotation in the axles after the driveshaft had stopped. I was able to track down a pair of Motorcraft CV axles to replace them. Even with the axles out and in my hand I can at best barely see/feel the play there was so little, but it was enough that even my wife noticed the vibration and it's been gone since, 12.5k miles later.

We always use the parking brake so it was engaged, she was standing on the brakes and I had all 4 wheels chocked. I didn't wanna get run over again, LOL. There is basically no axle clearance to these vehicles stock.

Anyway, I'd say look at rear u-joints or CV axles.