ok so...i did the research, bought the tools, a press, bought all the parts...gears...rear rebuilt kit....zexel torsen slp posi....

So after the *first* time i put it togather....had a .033 shim on the pinion....008 backlash..... put it togather...had a slight whgine that i could definatly live with...seriously quiet......all seemed good....until you hit 100 mph and a horrible vibration/Grindfing sound appears.....

so i check the drive shaft...all is good, never removed it from the tranny.....parket its relationship to the yoke...it went back in the way it came out...

tires are in balance... yoke seemed to be ok....

i yanked the rear back off, ...looked at the pinion..and notice the surface on the head of the pinion was slightly Not level...no big deal? i figured the pinion needed to be closer to the ring..

my assumption was that the uneven surface on the head --making the gears taller on one side than the other" was basicly rubbing on the ring and causing the grinding/vibrating at 100 mph...

sp i put a .036 shim on the pinion, slapped the rear back togather...put it back on....Same problem......horrible vibrating/grinding sound at 100 mph....

now i have no clue what to do now....the gears still have the same QUIET whine to them.......

they are used GM OEM 3.73s so...it was a real guess-timate on the gear pattern....the guy who sold them to be didnt paint the gears before he took them out to sell them --moron-- so i didnt have anything to compare the pattern to.....because theres no way it will give a good looking pattern like new gears will...

HELP !!!!!!!! i can live with it for awhile but.....who wants to go 60 on the highway ALL the time with 330 + hp.... NO FUN!!!!!

 

why don't you try setting pinion depth instead of guessign at what it might be? if the gears run in wrong it's too late to back up and try to fix them, you'll need new gears. i don't follow what you mean "the head isn't level" the pinion can only be located in one place, it can't be cocked to the side or off location. did you check the contact patten after you had the gears installed?

 

well.... what i mean by the head isnt level....is exactly that....the surface of the pinion head --very top-- .. wasnt cut level from the factory..... its hard to explain on here....its something youd have to see to understand

the head surface where it reads 11 - 41 has a uneven surface...a slope..... its slight...but still none the less its a slope....

and i guessed at the pinion depth because no matter what shim i used i couldnt get a pattern that resembled the one off of richmonds installation guide .... i could get the drive side perfect....the coast side however looked funny no matter what i did....i set the backlash to .008 every time i put a new shim in....

well if they are toast no matter what i do, i guess i am going to run them til they whine like hell and replace them...no point in not having a car for another month just yet.

i didnt have a pinion depth setting tool nor a depth mic....and no one could tell me what the pinion depth was supposed to be anyways.....i called several GM places since these are gm gears....they had no clue because it wasnt a *factory* set up....

i called richmond asking them what to do, and they said get the pattern to look as good as possible....its all best guess....bad advise on their behalf if you ask me....Best guess?? wtf.....oh well.....

i wish the guy would have painted the gears BEFORE he took them out and sold them....because i believe its damn near impossible to find a good pattern on used gears unless you have done it A LOT of times before.....or if they were painted before taken out to have a guideline to follow