I Have A Problem With My 2001 Jimmy, When Going Over 65-70 Mph, A Vibration Starts. Then It Gets Gradually Worse Until I Pull Over And Stop. This Vibrating Doesn't Always Happen Though. It Seems To Be Getting More Frequent As Time Goes On. We Have Checked The Obvious (brakes,tires,tierods,etc.) But Have Found Nothing. Anyone Know A Possible Cause? Please Help
I Did Have An Accident Which Broke The Grill(plastic), And Bent The Bumper Down About An Inch And A Half. Some Brackets Were Bent So The Hood Doesnt Close Completely. The Trouble Seems To Have Started After This Accident. And The Hood Isnt Doing This. Thanks Much!!

Things that need checked

Hub bearing
Idler Arm
Pitman arm
Ball joints
tie rods (inner and outter)
Check tire balance... One of your weights may have come off
Motor mounts (possibly cracked or seperated)


A visual inspection of the 1st 5 things may not be enough...
To check for the ball joints, hub, or tie rods Jack up the front of the truck... Starting with your hands in the 6 and 12 oclock positions, rock the wheel up and down...If there is even 1/8th inch play, your hubs or ball joints are most likely bad. Then at the 9 and 2 oclock positions rock left to right.. Any play and your tie rod is most likely bad.

To look at the pitman, idler arms, with truck on ground, rock the steering wheel back and forth, you should not see and slack in either of them. If you do which ever one has the slack is bad.

For the motor mounts, jack up the engine slowly via the crank pully and watch for seperation or cracks in the mount. If you see any then they will need replaced.

Any of these things can cause vibration as you describe... If all else fails, take it over to a local dealership and eat the 35 bux for a quick front end inspection and see what's up. Then youhave the option of changing it yourself or letting someone else do it.

Hope that helps

When did you check/change the shocks last? If its been over 50-60K Mi they are probably due. I've seen cars driving down the road with one wheel bouncing like a basket ball. The shock absorbers dampen out the springs natural desire to bounce/oscillate. If the shocks are gone the springs do what they want.
If its brake related it could be a warped brake roter. Make sure that anytime you have your wheels removed that they are tightened with a torque wrench to make sure that each wheel bolt is tightened equally. Uneven torquing is the leading cause of warped rotors. This is a trick that some shops use to get you back for a brake job.
Good luck
94

Thanks So Much Guys! I Will Have This All Checked Out...ill Let You Know Whats Up!!

If your truck is a four wheel drive, does the sound go away when you engage it into four wheel HI? I don't recommend shifting it into 4HI at 65mph, but if it is vibrating as you decelerate, shift to 4HI and see if the vibration disappears. If it does, your front diff may be trying to engage because of a faulty vacuum switch or because the cable that shifts the front diff was binded during the accident.

Did you ever find out the cause of your vibration ? I've had the same one for what seems like years...
Thanks for your time
SEDIVER

Did you ever find out the cause of your vibration ? I've had the same one for what seems like years...
Thanks for your time
SEDIVER

Join the club. I laughed when I saw your post this evening as I was just thinking the same thing when driving home on the highway today. We had snow this morning so I was in 4HI this morning and it was such a quiet drive. Coming home I was back in 2HI and it hummed every time I would decelerate from 60km/h down. I have had this problem since 27k and I'm now at 108k. I was into the dealer last week for a ride with the shop foreman and he was at a loss. He figures it is a bad axle bearing that under load (4x4) does not exhibit the problem, but once the load is not on the front axle the bearing has too much play. Extended warranty company won't allow him to dismantle the front end until there is a more definitive problem. They did wheel bearings, but no change.

Well almost 3 years have gone by and I read your post again today. Did you ever find out what was causing your vibration ? I still have my 1995 SLT Jimmy and its vibration. I've had a mechanic suggest rebuilding the front differential but I really don't want to put all that money on a MAYBE.

Well almost 3 years have gone by and I read your post again today. Did you ever find out what was causing your vibration ? I still have my 1995 SLT Jimmy and its vibration. I've had a mechanic suggest rebuilding the front differential but I really don't want to put all that money on a MAYBE.

I got rid of the truck as I couldn't deal with it anymore. The front diff failed a fourth time. I got it fixed and then sold it. The problem was never fixed, but I think they figured it was a bad pinion bearing in the front diff. For some reason they forgot to replace the bearing though when the diff was torn down. Worst truck I ever owned mechanically.

Has anyone checked the CV joints on the half shafts?

If you read the post the truck was sold, no reason to continue this, no?