I own a '95 4 door blazer with the 4.3 engine. The other day i was on the highway and I felt a strange rumbling that felt like I was running on the rumble strip when I wasn't. Then, I was trying to back out of my friends driveway and it seemed like it just didn't want to go. It almost seemed like I was trying to pull something and It just didn't want to go

 

Check your sway bar bushings for the rumbling issue

Here is some info on where to find it depending on whether you have a 2wd or 4wd


http://www.autozone.com/shopping/rep...00c152800c012a

May not be the cause cause there are many things on your suspention that could cause the issue.
Also does it seem to happen when you hit bumps and go around turns? or is it constant rumble no matter what speed or road your driving on.

Sway bars bushings / links are worth checking because they are easy to see and a relatively easy/cheaprepair.

Other issues could be anything from shocks to engine mounts could you describe it in more detail?

And does it feel like it has no power in Reverse only or also when you start driving?

 

Have the symptoms shown up other than those two times?

 

Check motor mounts and U-joints

 

The rumbles only did happened that one time and it was just short little rumbles, kind of like a rumble strip. And with the backing up problem, It will feel like a couple of little tugs and then Its a gamble from there. There are times it feels like it doesn't want to move and then it will go just fine.

 

U-Joint,please inspect!I just about lost my entire driveshaft down the highway,very close call holding it all together.