my 3.27 rear end used to always lay down 2-strips of tire marks when id do a burnout. and this was without the limited slip additive. (mobil 1 syn.) and then i started to hear some whining when id drive the car in the rain and the tires would slip.. so i thought that maybe i did need the additive. so i added it about 2 months ago. and since i had new tires i really hadn't done a burnout since then..

however i have installed a t-56 about a month ago. and have done two pretty big burnouts. (on somewhat slick pavement. well in a parking lot with crappy traction) and both times there was only ONE mark... but i did seem to spin more then i ever have.. which is weird with the t-56 and my rear ratio. so im wondering if maybe i kinda dumped the clutch a little to high\quickly and that there was too much power going to the rear end.. causing the posi to not work right? i mean i didn't just rev and dump the clutch. but i reved to about 1500 and let off of it kidna quickly while giving it alot of gass.

could my posi just be going out?? how can i check it?

 

I think we went over the subject of a full syn in the diff and why it wasnt recommended. I think that mileage (and drivin hard) along with the syn have taken their toll on your posi. But I am NOT blaming the fluid by itself.......

To check the posi, jack up the rear end of your ride and leave it in gear. Next, have one of the boys hold one tire in a fixed position, then turn the other tire by hand. You should have a fair amount of resistance before you feel it brake loose and then there should be some resistance while turning. If it is really easy to turn the wheel, with the other one stationary, the posi is most likely showing its age and may need to be replaced some time.

I hear what your sayin about comin off the clutch quick and having better traction on wheel and only leaving one mark. It is possible to have one tire hook better than the other and then all the driven power goes to one wheel.....yeah that too could cause premature (accelerated) wear of the friction material surface itself. But I think that your posi has seen better days and with the cool mods you have done, it is just showing its weakness.....

 

well i wasn't aware of all the controversy between synthetics and stuff for gear oil when i had put the mobil 1 in. but i have heard alot about how some people don't recomend it and other do. but i thought it wasn't as big of an issue on a cone type rear end.. but the only reason i got synthetic was becuase i heard that it helped reduce wear under the shock of hard accelerating.. (im not sure what its called.. something like film pressure or whatever.. forgive my ignorance..) but if dino oil is better then i'll get that. i odn't mind changing the rear gear oil yearly... its kinda fun ill do what u suggested tomorrow, jacking up the rear etc..

oh and i forgot to add that it doesn't help that this car has had 218k miles of abuse on that rear end!!!

oh and is there any way that i would be able to tell how bad the damage\wear is by pulling the cover and looking inside??

thanks!!!!

 

when you use mobil 1 synthetic do you still need the GM additive?

 

YES...but IMO you dont need to add the whole bottle......maybe 1/2 to 2/3....

 

thanks.. 'ppreciate it. some people were telling me u didn't need it but that didnt sound right.