Just picked up a 2001 Suoer, 3.0, 5spd 4x4 with 84k on it a couple of weeks ago. It has a vibration that starts real lightly at about 50 mph. It's irritating at 65, and fades at 72 and up. The frequency feels like drive shaft, so I took the durned thang out and greased the splines with some tefloned spline grease, and check the u-joints. The joints were smooth, no slack, and I marked the pinion flange. I have not put an indicator to the yoke yet, but it feels kinf of sloppy. The splines look OK, though. Further research revealed that I had cocked up the joint phasing, so I fixed that. The pinion seal was leaking, so I replaced it, and diff lube. None of this stuff has produced much effect on the vibration, but I see evidence of a slight leak at the transmission output, so I'm worried that I'm killin' the thing with this vibration. It looks like Ford hacked the original steel ranger rear drive shafts, and threw a 4" aluminum one at the problem. It's gonna really crank me off if I get the shaft balanced and still have the problem. What else can i check, and what's the going rate on an aluminum one?

 

did you get your tires balanced?

 

Tires or wheel bearing.
Driveshaft vibration doesn't go away, but gets worse with speed.

 

I'm in fairly serious money trouble at the moment, so I don't want to spend until I have diagnostic evidence to justify it. I haven't been thinking tires, because the vibration is felt in the seat, not the steering wheel. It seems to me that it's a tire thing, it has to be rear tires, so I should be able to rotate them, feel a difference. If that happens, I'll balance. Sound like a plan?

 

While you have the truck up check and see if it is wheel bearings. This is how you do it if you don't already know.

 

Holy crappinoli, 98Lifted - I hope to god I don't have that kind of play any where! I'll check it, though, probably Sunday.

 

both the wheel bearings on my truck were like that when they went. the driver side started humming a bit when me and a buddy were in the truck going to a racetrack an hour and a half away. on the way home the hum got louder, turned into a grind, then started clunking as i got off the highway. got home and jacked it up and the tire swung in a few inches. the passenger side went when i hit a large piece of steel on the road doing about 80km/h. it started to grind within 10km. made it home and had almost as much play as in the video. i have several friends with newer rangers and all have had the same situations when their wheel bearings go

 

Picked up first the front end, then the rear end with a fork lift today, so I could go knoggling around yankin' on all the tires, looking for slack and slop. On the front tires, I grabbed it top and bottom, no play, grabbed it front and rear, found some play in the steering. The joints at the steering ram seem tight, because both wheels moved together. Seems like hubes and ball joints are OK. Rear wheels had a little bit of axial play, and when I pushed 'em in, then yanked 'em out I think I was hearing c-clips hitting. Each side had the same amount of movement in and out, so I don't really see problems there. I got under it and mounted a dial indicator with the spindle on the yoke, just forward of the rubber yoke boot, and yanked around. I got a total movement of .040". I've seen .012" mentioned as the max allowable here, so I'm really thinkin' the stink eye on that driveshaft is looking more and more justified. Yesterday when I picked up the rear end and ran it up to 65 mph, I could not see run-out anywhere at the wheels, drive shaft, or flanges, but when the vibration started, it sounded like it was comming from the front of the shaft.

 

What a flat-headed, bannana-fingered clubfooted hook-handed.......... I had the dial indicator base on the underside of the body, so it wasn't just pickin' up movement in the splines - it was also getting tansmission/motor mount play. I clamped it on the transmission case, couldn't reach the yoke, so I put it on the yoke flange and got about .004" total throw. I don't like it, but I don't think it's the problem. I gotta rig a way to mount the indicator base on the tail shaft housing with the spindle on the yoke, but it's just too durned cold out there.

 

Update, girls and boys! Jacked up the a$$-end of that thang again with a forklift under the shock brackets, and had my neighbor whoop it up to 65 on the clock while I was under there marking the driveshaft high spot with a yellow crayola. When I got out from under, he strted letting it wind down, and that's when I heard the growl from the left rear axle bearing. I put the dial indicator to the rim and got .010" total throw. Gentlemen, I think we have our answer. I've ordered a couple of bearings and seals from dirtydogoffroad.com, and I'll take a crack at the fix next Saturday. I will be posting the results. In the mean time, I appreciate the help here.

 

Update again, Kids! - tried to get axle bearings from Dirty Dog Offroad, they took forever to ship, double dipped the shipping, then sent half the order - still waiting on the other half. Biatches. Replaced the rear left one, lit the truck off, ran it down the highway, and the vibration is still there, but it's reduced in intensity. I will by God NOT stand this, although I don't feel like running 68 mph is damaging my ride. If my other bearing/seal kit shows up, I may slap 'at sucker in there.

 

The other bearing/seal kit showed up from Dirtydog, but I no longer believe the bad bearing was it, and don't want to blow another $25 on diff lube to produce no effect on the vibration. I don't want to believe this, but when I cruised up to 80, I thought I heard a low hum with a certain buttlock effect, that I associated with the vibration, and promptly dropped mph.

 

IT WOULD BE CHEAPER TO HAVE SOME ONE LOOK AT IT AND TELL U WHAT IT IS INSTEAD OF GUESSING

 

^^^ What he said. Throwing parts at anything like a car, truck, tractor, etc. is an easy way to empty/lighten your wallet and bank account.

 

So far, the parts I've put in it, (pinion seaL and axle bearing), were confirmed bad, they just aren't the cause. I've never been a believer in problem diagnosis by parts replacement. Easy trap to fall into, though.

 

I put a dial indicator on the drive shaft, and got a total needle travel of .020". I think I'm gonna put the torch to the high side, get a dime sized spot to glow dull red, and hit it with some water. If it ever stops raining for the rest of my life.