Clunk?

[1999 GMC YUKON]

I have a 99 Yukon that I have noticed a clunk from the rear end. When you come to a stop it will clunk almost like the rear end and the driveline are unloading. When you start to go again it will have a hesitation like the driveline is loading and a split second later it will chirp and then go. If you start out slow it will not do it at all. I have noticed all of that lately and as the weather got colder I noticed that once in a while it wants to make a grind almost like the pinion is not getting to the ring gear far enough. I have talked to the techs at the dealership and they don't know. I spoke with GM and filed a complaint and they have never heard of it. I am just curious to know what the problem is and if anyone else is having it. A little history of the truck, 107,000 miles. I was in the military and I did a lot of driving. I tow a trailer so I put a 2 inch block lift in the rear to give it some better drive height when towing. All fluids are Mobil 1 full synthetic. I had to change the intake gasket at 100,000 not a real big deal. Cool air intake and a TB spacer helped with gas and power. All in all the truck has been great to me. Just some minor things here and there. I would tell anyone to buy one because of the power and the comfort. I would appreciate some help. I feel that I need to get rid of the whole limited slip crap and go back to the hypoid rear axle. Any coments will help. What have all of you done and have you had these problems?

Thanks

[huggins]

See your chevrolet dealer purchase part # 00347433 it is a small washer that goes into your slip yoke. worked great for my Denali

[mmulligan1]

I have a '97 Yukon (127k) and have the same problem. It has been making a whining noise since about 50k and clunking after stops. A mechanic told me that he thought it was the rear end, but since it isn't adversely affecting the performance of the vehicle I figure I'll let it go until something breaks and then I'll know what to look for.

BTW, where is the 'slip yoke' and how hard is it to install the part mentioned in the other reply?

[1999 GMC YUKON]

slip yoke comes from the transfer heading toward the rear. I think I solved my problem. I got to thinking about what all I did to that rear and I went with the most reasonable thing. I had 80/90 synthetis in it with the trans-X friction modifer. I went to the GM dealer and just got the 80/90 it called for and the friction modifer they give you that is GM spec (i think it was all 34.00$) so I changed the fluid and have not heard a chirp, clunk or a slip. I think that the trans-x stuff was just to much of the friction modifer for that specific application. There was clearly a difference in ammounts as compared to the little bottle from GM. I noticed that my rear had a lot of black stuff that was on the clutch pack and throughout the rear. I cleaned it with brake cleaner and let it drain. I then replaced the pan and gasket and filled it up. I tool it right to the parking lot and did anout 6 circles each way and then checked the fluid again. Like I said earlier I have not heard a thing. I hope this helps, let me know if anyone else tried the same thing and if it worked. I guess when the dealers say what is supposed to go in there they might be right(maybe only half the time) but they were right with mine.