80W-140 safe replacement for 75W-140 (South)

[OiledMustangGT]

I need some lube for my Ford 8.8 w/ a LSD specifying 75W-140 full synthetic. I live in louisiana where the absolute coldest it gets is 30*C

will 80W-140 Redline be safe to use? btw, fuel efficiency not much of a concern

 

[N2OIL]

since they make 75W/140 why not go with it?

 

[Michael SR]

this is an 8.8" in a mustang, correct? i'd say that's fine. i used torco 85w140 in about 15 mustangs where i changed the r&p, and never had a problem. a few of them were 10-second cars, too.

-michael

 

[OiledMustangGT]

the 80W is easier to find, and it has the friction modifier in it already

the 75W specifies it is not for LSD units

 

[Bio-T]

I use the 75W140 Royal Purple and it contains the LS additive. No problem in my F-250 with LS, I did not have to add any.

 

[Michael SR]

i always added the ford friction modifier anyhow. i used to rebuild the LSD with a different plate order and higher preload, and only the ford additive was ever successful in stopping the chatter.

btw, i have found this to be true in my vette, also. i have tried 3 different lubes, all claiming to have LSD additive, and all 3 required me to add some GM additive or the rearend would pop in parking lots.

-michael

 

[N2OIL]

The redline 75/140 has a fair dab of moly already in it. So most oils read *you may need to add a supplemental supply of LSD additive. The reason I mention is you can try a lube RL,RP,Amsoil,ETC and most oils read if it still makes chatter add the friction modifier. So for FORD you get the 4oz bottle of more moly they sell and add it a little at a time till it is quiet.

 

[Dominic]

I run the redline heavy duty shockproof (75W250) in my GM 7.625" Camaro rear... runs beautifully. Lower temps, no whine, I love it. Oh, and better torsen traction too

 

[Michael SR]

quote:

---

Originally posted by N2OIL:
The redline 75/140 has a fair dab of moly already in it... So for FORD you get the 4oz bottle of more moly they sell

---

i honestly don't know, but i question whether there is moly in either case. the ford friction modifier smells very strongly of sulphur. with the redline, we know from VOAs here that their GL4 lubes have no moly.

do you know these things for sure?

-michael

 

[OiledMustangGT]

I ended up putting in my 80W-140 and mabey 1/2 oz of the ford modifier. No chattter yet, and locks up a bit quicker, but not excessively at all.

The stock fluid at 3K had a good amount of sand sized metal on the plug magnet

glad I swapped it out soon ... I should be good for another 30k atleast

 

[dkcase]

quote:

---

the absolute coldest it gets is 30*C

---

whoa ! isn't that 86*F ?

 

[OiledMustangGT]

it was supposed to be 30*F..but I waited too late to edit and I was no longer able to