Originally Posted by Joe B
Reading the first two pages it seems Mobil 1 is the only fluid that caused a problem.
I have no problems.
A Amsoil Rep said the Severe Gear has the friction modifier but I could add a 4 ounce bottle of any brand modifier if I'd like.
I chose to add Amsoil's friction modifier just in case.
Wise decision.... However, I think the 2009 moved away from a traditional mechanical LSD.
They use a auto LSD which utilizes the computer and brake control to limite wheel slip. Therein lies the difference, hence no mech. lsd, no chatter.
"It's basically cost-cutting on Toyota's part. A mechanical LSD is a clutch operated device within the rear end (differential assembly) of the Tacoma w/ Sport Package 2005-2008. On an open differential, there isn't such a device, and when a difference in wheel speed between the left and right rear wheels is achieved, power is delivered solely to the spinning wheel since it has the least resistance in a wheelspin situation. With a mechanical LSD, the difference in wheel speed is reduced (not eliminated) because the clutch can partially lockup (hence why it's called limited
slip) the differential, thus allowing power to reach the wheel with traction. The amount of differential lock is limited, so LSDs can be overpowered. The threshold is usually dependent on how aggressive the LSD clutch is, and usually, road going production trucks generally don't see very aggressive LSDs from the factory.
Toyota's new Auto-LSD system is completely electronic, eliminating the need for the mechanical LSD. This system uses the rear brakes to limit the amount of wheelspin achieved. Think of the clutch in the mechanical LSD as an internal brake when its activated except it acts on the actual differential and not the wheels. When the Auto-LSD system detects a wheel spinning faster than the other (through the ABS speed sensor), it activates the rear brake on that wheel so the other wheel can get power.
They have the same premise, they just go about it in different ways. An electronically simulated LSD only wears the vehicle's brakes, whereas a vehicle equipped with an LSD wears the clutch/clutches in the LSD itself."