Highway vibration '99 Explorer

[Big D from CT]

Hello. First time poster, here. I've decided to seek help, from the great community of fellow Explorer owners, on a matter concerning an annoying vibration issue I experience on the highway. Before everyone jumps down my throat, I've already searched countless threads on here for a solution. Some share the same symptoms. But ultimately, many of the things suggested, I've already replaced or checked. Let me begin with what I'm experiencing.

This problem is mainly caused when I hit above 70 on the highway. Which also happens, to a lesser degree, and with sporadic frequency, on side roads. It begins with a feeling of something knocking around under my feet. It isn't provoked by bumps or road imperfections. It just happens to do this sporadically when driving off the highway. Then when I get on the highway, as soon as I hit 70, the knocking gets more pronounced. Followed by a tire out-of-balance, vibration feeling. Here's the thing, though. I purchased this Explorer about a month ago from a private seller. The thing was in great shape, so I pounced on it.

Tires looked practically brand new. The next day I took it on the highway (there wasn't a highway near where the seller lived) and I immediately felt the out-of-balance tire shake. So I took it in to get the tires balanced. Didn't fix my problem. Next thing I do is replace the entire brake system with new rotors and ceramic pads, figuring that maaaaybe the off chance that the brake pads were catching the rotors wrong. Or maybe the rotors were warped and causing the brakes to hang up. *BUZZER* WRONG AGAIN! So then I take my Explorer to a mechanic friend of my girlfriends father. He suggested I replace the front and rear shocks. I also had him check out ball joints, control arms, tie rod ends and basically anything he would think would be causing this to happen. And the tab keeps rising!!!!! Then I decided to pick up a used front drive shaft from the junk yard because the one on the truck had the inner tube of the drive shaft detach. Apparently the junk yard drive shaft was........JUNK as well!!! Same inner tube detachment. So I kept the drive shaft off completely on the off chance that it was a drive shaft related vibration. 3 STRIKES and I'm going out of my mind trying to figure this out!!!

Reading through several car and truck forums, I stumbled upon many people that suggested road force balancing. I decided to give it a go. What's a little more money being dumped into a vehicle I thought was mechanically sound? The mechanic drops an A bomb on me...........THE BELTS ARE SHOT IN 3 OF THE 4 NEW LOOKING TIRES!!! Turns out, from digging through many a receipt that the seller provided, that the tires had only 6,000 miles. But they only drove that vehicle 6,000 miles in 6 years! So it all made sense.

Friday, I had brand spanking new tires installed and balanced. Took it on the highway, and voila!!! My problem was solved. Or was it..................

Today I'm on the highway, and the knocking and a less prominent, but still evident vibration, under the floor starts up again. I can't catch a break! It's much better than what it originally was, with the bad tires. But I've owned enough vehicles to know what doesn't feel right or normal. The truck feels great 70 and under. It drives like a normal vehicle. But once it hits that 70-75 mark, it feel like a totally different beast. Accelerating faster seems to make the vibration subside. I'm at my wits end. PLEASE HELP!!!!!!!!!!!

 

[deweyville65]

So, did you check the u-joints, drive shaft, rear end, axle bearings?

 

[jremington59]

I don't see anything about getting the front end aligned. That could help drastically if it's out of line. You also want to check the main drive shaft for wear in the joint.

Also, you said the ball joints, tie rod ends and so forth were checked. Really check the inner tie rods with both front tires off the ground. If you get an alignment they will check all of that stuff.

 

[EastoutWest]

I've had two older explorers. The first one had a squeaking in reverse and a terrible vibration/rumbling above 70. It was a u-joint on the rear driveshaft. When I took the driveshaft off, the u-joint would barely move by hand. Replaced it and problem solved. My second explorer has just started doing the same thing (but not quite as loud and no squeaking). I will be replacing the u-joints shortly.

 

[EastoutWest]

And do yourself a favor if you do your own maintenance and get the u-joints with grease fittings.

 

[EastoutWest]

70 seems to be the magic number...

 

[Big D from CT]

So if the rear drive shaft is the source, would it cause front end vibration? And as for my alignment, it drives straight as an arrow with no tracking left or right. My front drive shaft was taken off just in case that was the problem. Thanks for the replies.

 

[EastoutWest]

I wouldn't think it would cause front end vibration, but someties the vibrations can trransfer through the frame and the drivetrain, which can be deceiving. Mine feels like an overall rumbling not location specific.

 

[deweyville65]

If you have a front end vibration, the steering wheel should be shaking. Is it?

 

[Big D from CT]

***UPDATE*** Just the other day, I put new sway bar links in. I also thought this was causing the vibration ( the links weren't too bad. But better safe than sorry ). So this morning I went out and made sure they were nice and snug and nothing was loose. It turns out that when I remounted the tires back on, they must've been put on crooked. I made sure to hold the tire in place this time when i sinched the lugs down. Now it's back to running better on the highway. There's still a slight vibration above 70. But it's noticeably better. No more shaky steering wheel. I still have something knocking under my floorboard, though. For some reason that only happens above 70 as well. These things don't like the number 70 for some reason.

 

[98EdBomber]

***UPDATE*** Just the other day, I put new sway bar links in. I also thought this was causing the vibration ( the links weren't too bad. But better safe than sorry ). So this morning I went out and made sure they were nice and snug and nothing was loose. It turns out that when I remounted the tires back on, they must've been put on crooked. I made sure to hold the tire in place this time when i sinched the lugs down. Now it's back to running better on the highway. There's still a slight vibration above 70. But it's noticeably better. No more shaky steering wheel. I still have something knocking under my floorboard, though. For some reason that only happens above 70 as well. These things don't like the number 70 for some reason.

Heres my list chasing my front end vibration.

upper control arms with bushings
sway bar bushings
sway bar end links w/bushings ( I tried tightening them really tight and now i have a clunk when i turn really hard or go over a speed bump at an angle) Both sides do this.
upper and lower ball joints
rotors
front calipers
front pads
front wheel bearings
tires w/balance (3 balances actually) I think they are as good as they are gonna get.

Next is shocks

Havent replaced the lower control arm bushings as they are a pain but they could possibly cause a vibration if they are really worn out. Mine look cracked but not torn to shreds. I have had this suv since it was new so i am extremely sensitive to anything that feels outside the norm.

Im checking the drive shaft u joints tomorrow in fact. The vibration is definitely coming from the front end though so i dont think its the drive shaft.

Good luck to you my friend. Seems this is a common issue once again with these Exploders.

 

[Joe Dirt]

U joints U joints U joints...

Let me guess- speed up, slight vibration starting at 65-ish. More pronounced at 70. Take foot off the gas, and even more pronounced under deceleration...

 

[98EdBomber]

U joints U joints U joints...

Let me guess- speed up, slight vibration starting at 65-ish. More pronounced at 70. Take foot off the gas, and even more pronounced under deceleration...

That sounds pretty accurate i guess. Also at 40mph i feel the steering wheel vibrate and in the floor board a little. Then smooths out a little until i hit 70mph. Just had the tires rebalanced again for the third time so i can almost guarantee its not them. Im checking the u-joints tonight. I forgot to check them when i greased my spline because of the 3-2 clunk, (which helped very little btw).

But If they move around easily and arent loose, could they possibly still be bad?

I also have a hunch my drive line may be out of balance. What would the symptom be there? Would I feel it more in my seat? I jacked the rear end up and put it in drive just so the wheels spun and wrapped my hand around the drive line very lightly and i did notice a VERY slight wobble if you want to call it that, but ive never felt one while it was spinning before so im not sure what is normal. It has 156k on it and my local drive line mechanic said thats pretty good distance on original u-joints.

Maybe you are correct sir. Thanks! I will get back to you and let you know.

 

[Mountaineer50]

Ok so I have been having the same problem and as it turns out I re packed and reseated the front bearings and what do you know it was gone...

 

[98EdBomber]

Ok so I have been having the same problem and as it turns out I re packed and reseated the front bearings and what do you know it was gone...

Yeah, same here. Just replaced the front bearings. Prob could have used the originals as they werent too bad but i said the heck with it and changed em anyways. Unfortunately the vibration still exists. Shocks come in a few days. Then im gonna try the u joints. I will basically have a brand new suspension system when im done. With my luck the engine is gonna blow after all that is done. Glad to hear you solved your issue though!

 

[98EdBomber]

U joints U joints U joints...

Let me guess- speed up, slight vibration starting at 65-ish. More pronounced at 70. Take foot off the gas, and even more pronounced under deceleration...

Removed the drive line and moved the joints around. They dont appear to be leaking and i really cant get them to move around either which way. They seem tight in the sockets with no play. They rotate both ways fairly easy. Oh well, i am taking it to get some new spicers installed and balance the shaft today. Im crossing my fingers it will fix this annoying vibration but im not too sure about this one.

 

[98EdBomber]

U joints U joints U joints...

Let me guess- speed up, slight vibration starting at 65-ish. More pronounced at 70. Take foot off the gas, and even more pronounced under deceleration...

Didnt cure the highway vibration. New spicer u-joints and a balanced drive shaft. Im getting two new tires tomorrow but i dont see it helping. With the new set (set of 4 3 weeks ago from BigOTire) i had 2 of them Manufacture defected out and those two new ones are now in the front and the same vibration exists. Im guessing with the two new tires I will be getting for the rear tomorrow wont cure it. Something else is going on for sure. Now I also noticed when i back out of the driveway at a severe angle, i can hear a clunk under my feet. Does it either way i back out and it happens when the front or the rear hit the gutter (its one of those curved gutters you have to roll over to get into the driveway.) The car rocks pretty bad side to side and this is when i hear the clunk. If i roll out at a straight angle, I dont hear the clunk.

 

[00EBV8]

I know this is an old thread but I have the same issue.

Once I hit 70 I get a light vibration/humming sound. Under 70 and its gone. Ive done a ton of research before i start replacing random parts and havet had much luck. My truck is a 2WD, tires are Michelin LTX M/S with 80% tread left. I had one U-joint replaced (other was fine) and no change.

I also get a slight humming sound at lower in town speeds, but no vibration. I dont get any feedback through the steering wheel when it vibratres, and it seems to come and go if I am going uphill on the interstate (load increased).

has anyone actually solved this issue??

 

[morbid81]

I know this is a old post, dont know if you ever got the problem solved. Have you check and replaced the cv axles? I had a 89 Bonneville had the same vibration issue at the same speed years ago and was the cv axles, it would also grind when turning that is how I knew it was them.