snakebit
05-29-2008, 11:54 PM
I had been using Amsoil Severe Gear GL5 in my 6-speed. It shifted kind of notchy and 3rd-gear downshifts tended to crunch unless I double-clutched perfectly.
On advice from a Supra mechanic (I heard the 6-speed is from Toyota), I did the following:
Drained the GL5 (2 yrs. old and looked very clean).
Filled the tranny w/ diesel and ran through the gears with car on lift.
Drained tranny and filled w/ cheapo gear lube, ran through all gears on lift again to flush out diesel.
Drained and filled with Amsoil MTG GL4.
The diesel flush allegedly cleaned out the fine dirt that can clog the synchros, inhibiting their proper expansion and contraction.
GL4 is alleged to not contain additives that are in GL5 which make it "too slippery" for optimum synchro spooling.
So I don't know which action/change had the most effect, but the shifting is vastly improved. 3rd no longer crunches at all and the lever action feels smoother and damper, almost like the mechanism is more cushioned.
This car has 64k mi., run hard but well-maintained.
On advice from a Supra mechanic (I heard the 6-speed is from Toyota), I did the following:
Drained the GL5 (2 yrs. old and looked very clean).
Filled the tranny w/ diesel and ran through the gears with car on lift.
Drained tranny and filled w/ cheapo gear lube, ran through all gears on lift again to flush out diesel.
Drained and filled with Amsoil MTG GL4.
The diesel flush allegedly cleaned out the fine dirt that can clog the synchros, inhibiting their proper expansion and contraction.
GL4 is alleged to not contain additives that are in GL5 which make it "too slippery" for optimum synchro spooling.
So I don't know which action/change had the most effect, but the shifting is vastly improved. 3rd no longer crunches at all and the lever action feels smoother and damper, almost like the mechanism is more cushioned.
This car has 64k mi., run hard but well-maintained.