think i got the shaft

okay this is a thread askin your guys honest opinions here goes.... i own a 91 rs and less than a year ago i purchased a rear end out of an 87 iroc, w/ had posi and disc brakes on it. i went to a shop to have it installed along w/ brand new calipers and when i got it back the brakes on the rear end didnt work hardley and they couldnt tell me why exactly..i did some quick research and discovered the proportioning valve needed to be changed when doin the swap to allow for adaquite pressure to the calipers, which i didnt know why they wouldnt know...but thats not my current problem just some insight as to how skillful they r... today on the way home from work i heard and felt a horrible knocking noise and am fearing its from the rear end...i was told the ring and pinion where brand new practically but told the shop to ckeck and make sure everything was okay w/ it. so heres the question if they didnt set the lash right on the rear and it broke a tooth is there any way to tell if the cause was from improper lash or not?? if that makes since. im takin it somewhere else monday and if its their fault for improper installation (not setting the lash) then do u guys think i would have a case...im only 20 w/ a meager job so money is few and far between and this bill is gonna hurt if i gotta pay for a new ring and pinion and have it installed, what do u guys think...thanx and sorry for the lengthy post

if its due to improper installation, then the shop may be at fault

oh yeah and the guy for tripple a that towed me home said ever car hes took there has had to be towed back to fix their mistakes that he knows of

Take it to a second shop ask their opinion if they did it. If it is like that start pursuing legal action

Well if you brought a shop the whole rear-end and they just bolted it in then they would have nothing to do with setting the backlash on the gears unless you told them to take the rear apart and do it.

Good news/bad news. good news is that if the shop just installed an entire rear end and the calipers, then if the rear grenaded it isn't their fault.
Bad news...the GM saginaw limited slip differentials were known (by GM) to be a POS and they replaced the ones that came in for repair with auburn units.
Also, there was a recall for the rear disk brakes on 3rd gens, but just foe manual trans cars, even though autos had the same brakes.
You can order the kit for repairing them from GM parts direct.

yeah i did tell them to make sure everything was okay on the rear cause i didnt have much knowledge about the who installed the new ring and pinion b4 i got it...but like i said even the tow driver said they r bad news. and i would think they would know that when changing to discs from drums that u would need a new proportioning valve. and as for the recall i bought after market calipers cause the old ones were sittin for awile and were locked up, but i still didnt have great breaking (i think due to not changin the master cylinder also) but they said it was cause i needed the ebrake braket for the disc brake rear to keep pressure on the pads. but on the reciept they wrote me im not sure if it mentions inspection or just installation but the rear cover was off when i took it to them. i took them everything even the limited slip additive hopefull tomorrow ill find out its just a transmition mount or universal joint or something and i didnt break off teath on the ring gear

It depends what type of garage you went to... honestly 98% of mechanics are just part changers they pull out something and replace it wit the exact same thing.

Unless you went to a performance/camaro shop it's not really there job to know you need a proportioning valve cause your modifying the car. Honestly that is why a good performance shop yo pay $75/hr and Joe Schmo's garage you pay much less.

Also I would not immediately jump to a broken tooth on a rear gear cause unless those gears were making a lot of noise before they don't just break out of nowhere.

well thats just it they have been making menimal noise but the shop said it was were the brake bad wobbled and not the rear end