02 Blazer - Clunking noise from front end

Time for an inspection. Sorry I can't be better help over a computer, but this should be checked by someone who can see it and tug on various parts. Blazers are known for two common problems but I'm pretty sure they both only apply to the 4wd versions. One is ball joints. These vehicles eat them for lunch and replacements are needed every 50,000 to 80,000 miles. The thing is though they won't usually make just one single clunk, ... Usually. That's why they should be checked.

The second thing is the rubber mounts for the cross member that the torsion bars are attached to under the seats. Usually they will rattle over bumps but they have been know to make one clunk when you start out. This won't apply if you have coil springs on front.

Caradiodoc

The typical symptom for the rear transmission mount is for it to shift position each time you hit the gas and put torque on it, even when the truck is already moving. If you have a helper you can trust to not drive over you, you can peek underneath at the transmission mount and the cross member mounts to see if they lift up when the transmission is shifted between drive and reverse and when doing a gentle brake stand.

Caradiodoc