01 explorer driveline vibration? PLEASE HELP possible axle problem

[windsorfan94]

ok i have a 2001 xlt with the 5.0 that has a amazing 210,000 miles on it and this is the first problem ive had so far besides routine stuff. ok so whats going on is while accelerating i get this bad shutter/vibration which feels to be somewhere in the rear end somewhere. it always starts at around 25-30 mph and begins to taper of at around 50 . the vibration gets worse if i apply more throttle buts stop all together as soon as i let off the gas. I was told it could possibly be a bad pinion bearing in the rear diff but im not sure. a few things i have also noticed is that when i first pull out and creep along under 5 mph i can hear this like squek squek squek sound that also sounds to be coming from the rear end somewhere and when im backing up ill here some popping sounds when i stop . idk if they are related to the vibration. i have checked u joints and there isnt any play. im going to lift car up tomorrow and check them again with the tranny in nuetral and all wheels off ground. important nothe , i noticed a small amount of gear oil had leaked out on to the rear diff where the shaft bolts up to the diff n i was told i needed a new pinion seal and that th pinion bearing was causing the vibration but idk because it was the trusty parts store guy who told me that so any advice on here would be greatly apreciated. again i feel the vibration from what seems to be the rear end at around 25-50 mph and it stops as soon as i let off the gas and gets worse with more throttle. thanks guys

 

[Sogsnakebite]

Sounds like a rear universal joint gone bad

 

[windsorfan94]

would the bad u joint cause the vibration at only certain speeds and stop when letting off the gas ? u joints was what i thought first cause i read on here that u will here a squeak that corresponds to driveshaft rotation as the u joint goes bad and i had that squeak before this vibration, im just hoping its nothing in the rear diff as this is my daily driver and i just spend 700 dollars having the entire exhaust redone

 

[thunderpipes127]

Mine was vibrating at 40 and when I got into the gas it got worse. Sort of a 2 second vibration then it would stop for 2 seconds and then vibrate again. Swapped out all my universal joints on the rear drive shaft and the ones for the 4wd drive shaft and it stopped vibrating never made a sound just vibrated.

 

[windsorfan94]

i will check the u joints tomorrow with the car lifted off the ground. i tried to check for play earlier and i only felt a small amount of play . from what ive seen a bad pinion bearing would have alot of play even when the car is on the ground . any other ideas on a possible problem to look for while im under it

 

[thunderpipes127]

Bad pinion bearing roar and very loudly from what ive dealt with. Check yur universals first. If it causing a severe vibration and it is the rear end something is very wrong. A vibration caused by the diff means something has a lot of slack or is getting ready to come apart. But you would have a sound along with the vibration. I have seen bad axle bearings cause a vibration but again it was a distinct metal on metal sound. From the sounds you described and the way its vibrating it screams slack/dry universal joints. The reason it stops vibrating when you let off is 1. the engine brake effect slows the drive shaft and lightens the load to an almost neutral like position with a lot less stress than when accelerating. 2. When letting off the throttle or braking you transfer the majority of the vehicles weight to the front tires and cause even less stress on the drive shaft. In reverse you stress the universal joints by accelerating and transferring the trucks weight to the rear tires especially when braking in reverse because it further loads up the rear tires giving you the popping sound. Pinion bearings can cause all of these also the effects from transferring weight and stress apply to it in the same way but a bad pinion bearing has always roared for me and the vibrations are at all speeds above 10 and constant every time I find one bad/slack. Give the universal joints a good hard look. I m sure your problem is in them and if you've never rebuilt a rear end it is time consuming but they are super easy as long as you get all the tools you need before hand and take your time and do it right. If you start to get aggravated with a job just step away take a break and come back to it when your less likely to get the BFH and smash everything in sight. Makes working on your truck a good bit easier.

 

[windsorfan94]

Bad pinion bearing roar and very loudly from what ive dealt with. Check yur universals first. If it causing a severe vibration and it is the rear end something is very wrong. A vibration caused by the diff means something has a lot of slack or is getting ready to come apart. But you would have a sound along with the vibration. I have seen bad axle bearings cause a vibration but again it was a distinct metal on metal sound. From the sounds you described and the way its vibrating it screams slack/dry universal joints. The reason it stops vibrating when you let off is 1. the engine brake effect slows the drive shaft and lightens the load to an almost neutral like position with a lot less stress than when accelerating. 2. When letting off the throttle or braking you transfer the majority of the vehicles weight to the front tires and cause even less stress on the drive shaft. In reverse you stress the universal joints by accelerating and transferring the trucks weight to the rear tires especially when braking in reverse because it further loads up the rear tires giving you the popping sound. Pinion bearings can cause all of these also the effects from transferring weight and stress apply to it in the same way but a bad pinion bearing has always roared for me and the vibrations are at all speeds above 10 and constant every time I find one bad/slack. Give the universal joints a good hard look. I m sure your problem is in them and if you've never rebuilt a rear end it is time consuming but they are super easy as long as you get all the tools you need before hand and take your time and do it right. If you start to get aggravated with a job just step away take a break and come back to it when your less likely to get the BFH and smash everything in sight. Makes working on your truck a good bit easier.

thanks for the helpful info, now that i think about it the car has always had a humming sound when i drive it but only at higher speeds of 50 plus and it doesnt sound abnormal, kinda like the sound big rig tires make when they are on the highway kindda like that hum but its been doing this since i bought it 14,000 miles ago so im sure its tire noise but i will check the u joints today and let you know what i find

 

[windsorfan94]

ok so i crawled under the suv today and checked the u joints and there was maybe 3 mm of play in the rear joint. i was suprised at what i believe to be the problem , so i had the car off the ground and the tranny in neutral and i was shaking the wheels to check and see if they had in movement in and out and sure enough the back wheel had about 3-5 cm of in and out play so i removed the wheel and brake calpier and rotor and the entire ale is moving in and out of the rear end , idk if this would be caused by a bad axle bearing or the locking pin that locks the axle into the diff has failed but it has me very concerned. any suggestions as where to start with this repair

 

[swetrid]

The in and out play of rear axles is completely normal. Your symptoms definitely seem like a u-joint problem. There should be no play at all in a u-joint.

 

[rb142]

I also think it is U-joints. Even if you don't feel any play at all, they can still be bad (especially at your mileage -- assuming they are original). They make noise because thay are tight, dry, and sticking, not because they are loose. When they get loose, they get quiet (or at least make a different kind of noise). 3mm of play is a lot. Start by changing those -- they are cheap anyway. Lube the slip joint while you are there. If the pinion seal is leaking, you will need a new seal, but not necessarily a pinion bearing.