Well mostly just a shake and thought I would ask if anyone has a solution. My 99 has a vibration in the drive train some place. I have a v6 with 5 spd and driving down the highway 60-70 I can feel it shake. 86000 miles Goodyear wrangler tires. Tires just recently balanced and both upper ball joints replaced. I thought it fixed the problem but seems to be back. I can feel the vibration and look at it in the passenger seat. I think I will replace the u joints next then both tie rod ends, or if someone know the exact problem go right there.


Bill

 

I would try going 65-70 on the highway and then shift into neutral. If the shake goes away, you have eliminated tires and tie rod ends. Most likely problem could be u-joints. The way I check u-joints is to put the rear on jack stands and have somebody run the speed up to 60-70 as you watch the drive shaft turning. If it grows at that speed, it needs u-joints.

 

So I went 65-70 on the highway, shifted into neutral and it still vibrated. So what does that mean?

 

Get the rear wheels off the ground (on jack stands, preferably) and see if you can shake the drive shaft at each U joint. If there is any looseness, there is your trouble maker. Running up to 70 mph, especially, if one wheel doesn't spin as fast as the other, may cause a tire explosion.

 

could be your axles, watch your back wheels in the mirror... also is this 2wd or 4wd?

 

Its 2wd. I will jiggle the shaft at both ends and check for looseness.

 

Doesn't this mean it is most likely the front end? check your lower ball joints. your outer and inner( they are under the bellows) tie rods.. check that your wheel bearings are ok

 

I side with powersmoked for checking all front end components. And running the drivetrain at 70 mph on jack-stands sounds like a prescription for disaster. If the vibration caused the vehicle to come off the stands while doing that, someone could get killed!

Also, you don't need to jack up the rear to wiggle-check the u-joints. Doing it on all four wheels works just as well.

 

I will check the front end components again tommorrow. I guess I need to jack it up and check them. I did put the truck in nuetral and slid under it the ends of the the drive shaft seem tight there was not any apperant looseness there. I do have some oil seepage from the front and rear tranny and diff seals, if that is an indicator the drive shaft may be out of ballace some how. THe left rear driver side wheel/tire did have a bit 1/8 in of in out slope to it. Not sure about any other up down movement as I have not jacked it up yet. I had the tires balanced less than 1000 miles ago which felt like it helped the vibration some but it is back. So I'll keep looking and eventually track it down.

 

Update everything else checked out to be OK. I narrowed it down to the left rear tire. Way out of round for some reason and plenty of balance weight bars on it but just not enough.

 

If you have a tire badly out-of-round, the solution is to replace it. While you are at it have the wheel checked to see if it is running true and round.

 

Another thing you might check is the balancing weights on the drive shaft. I knocked one off when I was changing U-Joints but when I welded it back I think it must have moved because there's a tiny vibration right around 65-70 now.