now is getting worse........

I can't point out what's causing the clunk, but it sounds like it's coming from the rear end, U-joint or diff.
But on visual and hands on inspection I can't find any play in the U-joint...
I put the blazer in neutral and put on the emergency brakes and twist the driveshaft,
still I can't see any play in the U-joint.
With my wife behind the wheel, foot on brake going from D - R there is NO
visual play in the U-joint. Could the U-joints still be bad?
For me it sounds like the sound is coming from the diff.
I have pulled and pushed the diff pinion up and down, right and left but I can't see any play there either.
When I twist the driveshaft I can hear a clunking noise coming from behind my brakedrums,
I do know that I have some wear in my wheel bearings, could this play result in a clunk in the rear diff when
engaging the drivetrain?

I also from time to time has some rubbing noise coming from the rear diff when I start to drive coming from a full stop. This goes away in second after the blazer starts rolling. It feels like there is something binding.

The winter is just around the corner and I need to get this fixed before the white stuff comes, as the garage is out of room

 

its a 95 with alot of miles im guessing,which makes me think a diff issue. if i were you i would go to your local junkyard and get a complete diff and swap them out, should be fairly priced ($75-125), i had a blazer with a diff noise and know of two others that had problems with their blazer diffs. i did mine in a few hours with a buddy and some basic hand tools on the ground. i ended up replacing mine beacuse i ignored the noise and my pinion bearing blew apart and the pinion slammed into the carrier and chewed the ring gear. not a pleasent sound. so my recomendation is swap the diff unless you can pinpoint the noise to be something other than the diff.

 

have you opened it up, to @ least look inside, see if anything is visual?


i'd dig a little deeper before doing a diff swap. while it's not that difficult (even easier when it's a 4-wheel disc set-up), i once drove almost 2 hours (each way) to get a diff for one of my trucks, only to have it howl like mad as soon as i put it back on the ground.


if you're really stuck, take it too a few different driveline shops, have them give you an estimate of what they think it may be.

if you get a few that are pointing in the same direction, then pick the one you feel was the most honest/trusting, and take it from there.

 

....and one more thing, its not there when the drivetrain is cold or when I engage 4wd!

It's sound exact as a bad U-joint. clunk from R-D, and sometime when I step off and on the throttle again. But as I wrote, I can't find anything wrong with the U-joint.

 

that's internal (ring/pinion banging into each other), i'd be getting that diff cover off sooner than later, and just inspect what is there.

it could be your pinion bearing is collapsing. something is sure sounding like it has increased the backlash.

please be smart, look @ it real soon. or have a shop look in there if you don't have the time or knowledge.

 

u joints are cheap replace a couple and go from there

 

Sounds like the carrier is cracked to me.

 

cheap or not, why throw money @ a problem if it's not the cure.


funny...........we never did get an update from the OP about what he found out.

 

very good chance it could be a u-joint, cheap to replace and if it ends up being something in the differential, well, he has new u-joints which probably needed replacing anyways...lol

 

again, says who?

not trying ot be an *** about that point, but i has some tool tell me to replace the factory original, front u-joint in my '84 Blazer (had 358K on it). the new ones never lasted more than 18 to 20 months under the same driving conditions.

and i only use top quality parts, no off-shore China crap.