Awesome thank you lot of great info there!
I lost the final round of the Phoenix/Tuscon street shoot out race years ago (1988) with synthetic gear lube.
I was looking for an edge and the fuel /oil vendor suggested synthetic gear oil. I replaced the regular stuff in the pits before the final round. I launched and got about 20 feet out on him in 2nd, went into high at about 90 and the car promptly turned right! I backed off got straight and never caught him. Lost by about 3 feet. Made another pass later and it did the same thing. Switched back to dinosaur 90wt. and it was fine.
He was the one that told me to do the circles at walking speed to relube the clutches after changing back to Dino lube.
I discovered that doing that once or twice a month eliminated the clutch chatter. When driving, the ring gear slings the lube out and away from the clutches.
Synthetic lube reduces the posi action in a gear type posi too. The only posi I will use synthetic with is the old Detroit Locker, or its derivatives. Nothing with gears or clutches. With the Detroit locker installed and trying Amsoil gear lube, the car picked up about a bit over half of a tenth (about 6 feet or so).That's on a street driven, mufflered, ps, pb, ac, 10 second Chevelle in 1988.
Foto is on borrowed slicks, it didn't run any faster than with the Hoosier 295/50 street tires. I ran those for years! It even ran 9.90s@139 with a small plate system.
P.S. all of this was with 12 bolt, 3.73 rear, Moroso Brute Strength extra clutch plate posi.
TIMINATOR
(That was one of my street cars that got me the TIMINATOR nickname back then. The other was my street driven 68 (9.60 @ 141 mph Nova) In 1988 that was considered fast for a daily driver.)