vibrations at ALL speeds except around 38 and 76 MPH???

[hbergh]

I had new Michelin tires put on my Navajo a while back, and some time after that it has started vibrating at all speeds except around about 38mph and 76mph. Oh, and 0mph ... ;-) And it keeps getting worse.

I checked tire pressure, and it was high on some, so lowered those a bit. They're all at 30PSI now, same problem, still getting worse.

Since it vibrates at any speed EXCEPT some, does that point to a particular problem? Something loose in the suspension? Loose wheel? I'll get under the truck later and see if everything appears tight.

If anyone else has experienced this, please post.

Thanks,

Herbert.

 

[sirhk100]

I had something like that happen on my CJ7 a while back it turned out to be the ujoints in the drive shaft. I've heard to check them you just crawl under and try to move them in any way. If there is any free play in any motion they're bad. I'm not sure about this though so get a second opinion. Also try pumping them with grease assuming there's a fitting on them. Anyways just something to check out. I'm sure others can direct you more on this as well as on other things to check.
Khris

 

[flatlander]

Mine would start shaking around 50 and it turned out to be the ball joints

 

[Gary Steeber]

Originally posted by hbergh
I had new Michelin tires put on my Navajo a while back, and some time after that it has started vibrating at all speeds except around about 38mph and 76mph. Oh, and 0mph ... ;-) And it keeps getting worse.

Like SIRHK100 said, I would definitely check the drive shaft and u-joints, this could cause vibrations at various speeds.
But, have you had the new tires re-balanced since you've had them? Seems to me that your problems began with the new set of tires, who ever mounted and balanced them could have messed up. I would take it back to the tire store where you purchased them and tell them about your vibrations and make them re-balance them. Most reputable tire dealers will do this for free as part of their warranty service.

 

[hbergh]

problem fixed.

Thanks for the suggestions. I took it to the dealer, and they found worn bushings on the left front suspension. After replacing them and aligning the suspension, the problem was less, but not gone. And it was getting worse every time I drove the car. A week later I crawled under the car and was shocked to find the drive shaft almost coming off the gear box. One bolt was gone, the other 3 were about a 1/4" loose. I guess I got really lucky it didn't drop out while going the speed limit on the freeway...

After tightening the remaining 3 bolts, the vibration was gone. The Mazda dealer didn't have the bolts in stock, so picked one up at Ford. Their illustration had the wrong part number for the bolt. Will get 3 more to replace the others, now that I know this one fits.