I bought a 98 blazer 2door a month ago, and on my first drive with it there was a godd vibration over 50mph. I've balanced the tires (no force balance, the guy didnt have the machine), but no change, still vibrating. I've look up the u-joint, and they're all perfect.

Today i've put two jack stand under the rear diff , just high enough so the wheels does'nt touch the ground and make it spin up too 70mph. There was no vibration at all!

SO i'm lost there, someone got answer?

 

Could be the alignment is out a tad bit. Trying to track down resonate vibration can drive a body insane sometimes. I've got the same thing with mine, though at 65-70 mph. I'll be getting all the tires balanced tomorrow and hopefully that takes care of it. If not, alignment. If not, I'll pull the drive shaft and check the balance on it checked. If not, I'll be on here asking questions.

 

Did you check all your ball joints, tie rod ends, and idler arm?

 

All seems good.

 

Check your front driveshaft. There is a CV joint on it that can go bad. Just put it in park, crawl underneath and see it it has any lateral (up/down/left/right) play near the transfer case. When mine was bad, I felt a vibration under the floor, drivers side. Also my front hubs were staying engaged, causing the front driveshaft to be driven by the wheels all the time, and causing the vibration even when in 2wd.

 

Yup I just receive the same message on another board, I'm gonna chek this out tonight after work!

 

So I look up my front d shaft and it doesnt disengage, so front dshaft coulb be the problem. But it's minus 20 degree celcius outside here, so i'll wait a day or two! lol

 

Just thought I'd follow up. Simple balance of all four tires cleared up my vibration.

 

Your lucky, still working on mine! lol