As related in another thread - my switch to Amsoil 75w/140 in my LS differential effectively rendered my LS action useless - one wheel would spin merrily away on a slippery surface, while the other just sat there doing nothing - and that was with NO friction modifier added, which presumably would have only made the problem WORSE...
The fix has been to drain the Amsoil out, and replace with Valvoline 85/140 synthetic blend meeting API GL5/MT1 specs. A short trip and a half-dozen figure "8's" has restored my differential to nearly perfect LS operation - and I have little doubt a few more miles will completely do the job - if it gets TOO tight, I'll drain off a quart or so of the current lube, and replace it with a equal amount of the Amsoil I drained out - that should do it!
I suppose many folks really don't care, or NEED an operational LS differential in their applications - but I wonder how many others are driving around after switching to a full synthetic, and no longer have an operational LSD...

The fix has been to drain the Amsoil out, and replace with Valvoline 85/140 synthetic blend meeting API GL5/MT1 specs. A short trip and a half-dozen figure "8's" has restored my differential to nearly perfect LS operation - and I have little doubt a few more miles will completely do the job - if it gets TOO tight, I'll drain off a quart or so of the current lube, and replace it with a equal amount of the Amsoil I drained out - that should do it!
I suppose many folks really don't care, or NEED an operational LS differential in their applications - but I wonder how many others are driving around after switching to a full synthetic, and no longer have an operational LSD...



Last edited: