When i am driving at a speed around 80 km/h, and a RPM between 1500-2000 i get one hell of a vibration under the car. The whole thing shakes.
But it only happens in the overdrive gear. Or the 4 gear.
What could it be?
S10 Blazer 1985 2.8 V6

Thanks

 

how long has this vibration been happening? have you had ANY repairs doen to it recently? You may have a bad tire or tire(s), there could be plenty of reasons for veh vibration..try to give us more info... Do you hear any clunking also when you put it in gear? It could be bad U-joints.... If the tires are good then poss bad balance on them..

 

It kinda happent after a off roading trip. Its not the wheels, it sounds like perhaps the axel. But like i said it only comes on a spesific RPM, speed and when its in overdrive. When the sound comes i just push down the throttle and it disseperes.

 

No one that knows what i could be? It`s driving me crazy. Using dobble the amount a fuel since i can only drive in 3 gear.

If anybody knows something please shout out. Thanks

PS: It really sounds like the sound it comming from the back axel.

 

I'd drop the driveshaft as previously stated and check out the u-joint's. Also, jack up the rear and put it into drive(when SAFE) and rev it up to see if you see/hear anything. Would have chimed in earlier but I have a job and sleep at night. Jerry

 

i have a similiar problem, what I have is a broken belt in one tire

 

I`ll try the u-joints first. Sounds like that could be it.

Thanks

 

I had this same problem, Around 55 mph the blazer wobbled like crazy. I replaced the U-joints in the drive shaft and good as new.

 

Same thing that happens to mine. So its the u joints then. But the thing is that i cant find any internet sites that sell them!

Anyone know a place where i can get them?

 

Maybe your driveshaft is bent ever so slightly? It wouldnt vibrate until you hit a certain RPM. That is, if it is the slightest kind of warp in the shaft itself. You may want to see if it's straight while youre under there checking those U Joints. The theory of resonance supports this thought. In otherwords, the slower it spins, the less you would feel it. You were off roading, correct? You may have hit something underneath.