Hello,
2000 Blazer 4.3 4wd 4dr. 160,000 miles. GU6 Code for rear end.

I appreciate any help with this.
The drive shaft will spin 1/4 to 1/3 turn without any wheel movement which leads to a harsh clunk. The vehicle drove fine, no noise, no hesitation. I set it in drive and I heard a slight clunk as I pulled from a parking spot. I drove 1/4 mile and heard the noise and felt a very light kick from the rear a couple of more times during slow turns while exiting the parking lot. Once on the high way and/or any speed over 5mph the truck drivetrain seemed fine.

I checked the U joints and their good. I set the parking brake, had a helper move the selector from P to R to D with wheels on the ground. I can see the drive shaft and rear yolk spin approx 1/2 to 3/4 revolutions prior to engaging solid to the rear wheels. I thought I could possibly hear the right side axle turn or for the least maybe it was the rear gears and the sound travelled.
I'm mechanically inclined and able. I'm good with going for intricate fixes if possible over a swap out of the entire rear end

Thanks
Stephen

 

I removed the cover and found one of the small gears on the axle was shaved. Any opinions on whether it's worth replacing the one gear or with 160,000 is it a good time to swap out the entire rear end with a salvage unit? I also see an ebay seller with complete carriers minus the ring gear selling for under $50.00. Is it a straight forward swap or would I be needing measuring equipment and shims to complete the job?

 

I blew up my rear end and instead of trying to replace the 3rd member i got a whole axle with a 199 day gaurantee that had 50k on it for 350 bucks on e bay from http://cgi.ebay.com/ebaymotors/2002-...QQcmdZViewItem. you might want to look at one of these. Only took me about 2 hours for the whole change. I did put new rotors and pads while i had everything taken apart. Just my thoughts because to me this is a lot easier. But as we say just my 2 cents.

 

Since you don't have to take the pinion out it is not too difficult but you will need a dial indicator and shims to set the clearance between the ring & pinion. When you remove the carrier you can use the factory spacer from the pinion side of the carrier. Measure the thickness of the other spacer with a micrometer. Then go to GM & buy the shims necessary to equal the thickness of that spacer. Put the factory spacer in where it came from first. Then tap the new shims into place. You should never tap the cast iron factory spacer into place as it could crack. The bearings are designed to be under pre-load so you have to tap the shims into place.

Then check the backlash with a dial indicator. If the ring gear mounting surface new carrier is not the exact same dimension as the old one the backlash will be wrong. If so you need to get more shims and move the carrier the correct way to get the correct backlash.

It would be best to have the manual to follow.

Make sure you clean all the metal out of the axel housing and put new axle seals in when you have it apart.

 

Thanks for the replies.. Based on the high mileage I went with a full replacement axle that came out of 2003 with 67,000 for $400.00. Sort of glad I did as I replaced the brakes and found a frozen caliper which more than likely contributed to the stripped axle gear. It's a simple straight forward job though loosening 8 axle nuts without an impact will get your arms tired.