my yj 8.8 rear 4.88 gears has seen better days,its just had the pleasure of being treated to a lock-right(i argue the name) but all the tolerances, pinion height, backlash, well everything was set up professionally and it sounds like death, not the ignorable clicking described in the manual but what feels like a binding drive line ,im driving then *bang, it feels like one side of the rear has a strap around it and someone else is tugging in the other direction straight or around turns at random with a little throttle or alot. any idea? info? cause this noise is s#@tty and my wallets hurting already.  

Wtih both rear tires off the ground, tranny in gear or park, spin one tire. What's it feel and sound like?

With one rear tire on the ground, tranny in neutral, spin the other rear tire. What's it feel and sound like?  

both tires off the ground trans in gear the tires wouldn't spin then all the sudden one tire let loose and ratcheted back a quarter turn and stopped not to spin again.One tire off the ground trans in neutral my tires wouldent spin, no sound no nothing just solid axle with about 1-2 inches of forward and backward play. it seemed fine at first for 20 minutes or so(only seemed more like a spool not unlocking in turns on or off the gas) then while pulling a hill it started popping and steering the jeep side to side.The popping made way to an in unpredictable intervals sound like an auto tranny being neutral dropped (the death sound) all on my way home nice maiden voyage..thanks Richmond.. Any idea??  

How about both rear tires off the ground and tranny in neutral?  

Sorry. One more test. Both tires off the ground trans in gear or park. Rotate one tire forward and the other in reverse. What's it feel and sound like?  

Yea i tried that too and it was just stiff, with a normal amount of play forward and back but no break of the wheel for its expected rotation or (ratcheting) Thrust washers? gears out of mesh? I just wish i learned to set up rears! Im saying, it feels like a spool,it should give i just read the owners manual and know that it should ratchet but doesn't.. it did let loose at one point so i know what the slip should feel like and sound like and the noise this is making is foreign.. on road only though in the drive way it was normal just locked and quiet??  

Both tires off the ground, in neutral, both tires rotating in the same direction, would exercise the carrier bearings, pinion bearing and gear backlash.

Both tires off the ground, in gear or park, with one tire going forward and the other in reverse should be allowed. This is where you should feel slight resistance and a slight clicking.

The other tests show if the locker is locked.

There is certainly something wrong with the "differentiating" of the locker. Installed incorrectly or wrong locker for the carrier??  

well i trust randy's ring & pinion didn't steer me wrong one the whole parts list seeing as i got the carrier, locker,yukon r&p,and master install kits for my 8.8 all in the same order from the same person ive dealt with there before. granted mistakes happen, but the install people seemed more so shady..I would like to bring it there and take the guy for a ride to show him but ive already drove 3-4 miles back home after it started auto disassembling (thats the funny) yea guess it turns into one of those you did it, i paid(time and money)now fix it right..!the only thing that was weird was with 4.88 gears i needed this cross shaft that had a flat spot in it to clear the height of the tall gear maybe it rotated in the carrier?even that probably wouldn't do this.I could bet id be able figure it out the problem if i pulled the cover for a once over but i already paid someone to do that! what would you suggest? you know it it'll be the old "it was fine when it left here" song and dance.