Good afternoon fellow Blazer owners. I have a 2003 ZR-2 that will roll backwards in reverse no issues. When I push the gas to get it to go a little faster I get a vibration/shutter. I looked at other posts and they mention maybe something inside the diff could be the issue, others mention U-joints. I just wanted to see if anyone else has had this problem and what either fixed it or different things to inspect to find the issue? It just seems as if it can't transfer the power to the wheels when its shuttering. Thanks for any help in advance!

 

I had a similar situation where it turned out to be the drive shaft u-joint. That's the most simple. If you have the ability, put the truck on stands, and have an assistant let the truck idle first in drive, and then switch to reverse while you listen beside the truck. Don't rev the engine, just let it idle. If you're lucky you can hear where the problem is occurring. On my truck, I could hear the bearings in the u-joint clicking/pinging when the truck was in reverse.

Good luck, and be safe!