Howdy fellas,

i am in need of your help. this evening i was driving home and i decided to stop and test out my recently installed posi unit. i did 3 launches from a stop and each time the posi worked correctly and hooked pretty decent. i did this after driving the car for 40 minutes (15 city, 25 highway), so everything was nice and warm and lubed. however, when i went for another drive on the highway (2 hours later), i noticed a VERY loud whine coming from the rear end. it only does it when power is being applied. it does not do it when i coast.

i have just recently put in a used posi carrier and some used GM 4.11 gears (GM was stamped right on them ans so was 37 and 9, so i know they are factory 4.11s, most likely from an S-truck) in the rear end. i replaced all the rear end bearings and the pinion nut and crush sleeve. i had someone help me do the swap who has done them before. we carefully set the pinion depth and backlash (set to factory specs). i used amsoil series 100% synthetic gear lube (the series 2000 racing stuff) and their posi additive. other than this my 10 bolt is stock.

so what did i break? as we all know just because something is new doesnt mean it cant break, so did i wreck a bearing or have the gears come out of "alignment"? i could really use some help here. i could care less about the noise if everything is fine, but the fact it only apeared after i did some drag style launches makes me assume i grenaded something.

 

pull the cover and look. i'd check back lash too while cover was off, maybe even pull axles and carrier and recheck pinion depth and preload.

 

i definetly will be pulling the cover. i did this last night at about midnight so i didnt have time last night.

i am somewhat concerned about driving home to work on it. it seems to drive fine, no issues there, yet....but i am afraid that i will be do further damage.

i am assuming that i havent ripped the teeth off the gears cause it was still driving fine....but who knows. i will try to get the cover pulled today or tomorrow. thanks for the help ede

 

after doing some research and some investigating, i think it i may have trashed the pinion bearing. i will find out tomorrow when i have time to really dig into it.

 

or you peeled a tooth off the Pinion Gear. Happened to me just the other day. Gets real noisy real fast...will still drive....but not for long