Redlinez

iTrader: (5)

I hear ya, but everyone's science doesn't seem to agree. Every manufacturer of automotive lubricants has tests to prove how superior their product is. I never know who to believe. I've been a service advisor for 10 years and have only seen differential and transfer case failures due to lack of service, no fluid, or severe abuse. Maybe in the racing world, you have other evidence- after servicing seeing the fluid coming out and looking or smelling distinctly different than others, monitoring rear end temps during high speed racing, etc. Our shop techs all run the 75/140 synthetic BG fluids in every car and haven't seen a single issue. Of course, these are not racing applications so maybe it's not a good comparison. I did bring up that mine calls for 75/90, but they are convinced the 75/140 BG will work fine.

2 fast 2000

iTrader: (4)

I changed my fluid from conventinal Valvoline to Amsoil synthetic and at the next TNT at the dragstrip, first pass the ring gear broke! This was a 12 bolt too! I did alot of research on fluids after this only to find out that synthetic fluids are not recomended for a drag race rearend. They are thinner quality. Don't believe this just call Strange or Moser and see what they say. They only recomend conventioal fluid for there rears. As a matter of fact Moser would not replace anything under warranty because I had put synthetic in it. Got a Strange 60 now and they also recomend conventioal fluid! IMO synthetic fluids are not crap in rears as compared to there durability in motors.

MannyZ28

iTrader: (1)

Well...how about synthetic fluid for just average non drag strip use?

chicane

If I were to do so... because I have had clients insist on using it... I would use a higher weight than 75-90.

My overall recommendation for any performance build, strip use or not, will always be a straight weight 140... or from what is available in a full syn... an 85-140 like what is available from Torco or Amsoil.

2 fast 2000

iTrader: (4)

After my experience with synthetic I would not recomend it for any rearend! Weather it be drag or strip. I'll put a 75-90 coventional against against a 85-140 syn. anyday of the week. I'm not trying to give synthetic a bad name, because I swear by synthetic oils for motors, and thats whats in mine! As far as the rear goes, I've learned my lesson and will never stick that sh*t in my rear again!

SpdFrk1990

iTrader: (6)

So I guess you would not recommend mobil1 either?

chicane

I am sure that I speak for all here... but I hope you dont stick anything in your rear from the get go.