Trans Shifting Issue

[z28z11]

While we are discussing trans and diff lubricants, anyone old enough to remember why you had to add a bottle of limited slip lubricant to the rear (after the late 60's ?). Hint - Something was taken out of the gear oils used with positractions.

Good Double Bonus question -

Regards,
Steve

[olddragracer]

The additive was used to modify the slip factor of GL4 lubricant, increase its slip factor, and stop the limited slip clutch plates from chattering going around corners. Whale oil was used in the additive. The use of whale oil stopped with the whaling ban.  The new stuff has never worked as good.   my opinion

[olddragracer]

additive has been used since the 1950's

[z28z11]

You are correct - my first posi (69 Z) was my intro to the additive. Amazing to believe whale oil was ever used at all -

Wikipedia states the ban went into effect in 1972, prior to that 30 million pounds a year were used for transmission fluids and gear oils.

Regards,
Steve

[69Z28-RS]

I bought a few bottles  (which I still have) from my local Chevy parts store before they all disappeared... 

[ZLP955]

Whale oil..... might explain why used rear end oil used to stink so much.