C2 DIFFERENTIAL/POSITRACTION LUBE

[Rob A.]

When I got my differential back from the rebuiler he gave me a quart of "Lucas" heavy duty oil stabilizer and two small bottles of "friction modifier". I am wondering how much of these to put in and make sure I have enough room for the actual gear oil. The case contains no lube yet. {by the way, the friction modifier absolutely "stinks".

[Michael W.]

Re: C2 DIFFERENTIAL/POSITRACTION LUBE

Lose the stabilizer stuff, unless it's actually oil for the diff. Your GM dealer has the correct oil, put one or two bottles of friction modifier in first, then top it up with the oil.

[Joe L.]

Re: C2 DIFFERENTIAL/POSITRACTION LUBE

Rob-----

Old versions of the posi-additive ("friction modifier") were actually composed largely of whale oil. As far as I know, that stuff has been gone and off the market for years. In fact, I think that whale oil as well as all other whale-derived products may be banned in this country, as they are in many others.

The current GM posi additive is the one to use---GM #1052358.

[Duke W.]

Re: C2 DIFFERENTIAL/POSITRACTION LUBE

Yes, back in the early days the positration additive was whale oil based, and the old, original type A suffix A ATF also had a small amount of whale oil. The small quantity of whale oil helped the wet clutches operate chatter free.

Whale oil products were outlawed for sale in the US in the early seventies,and I believe that the current positraction additive is a synthetic product, which probably lasts longer because most animal and vegatable-based lucricants breakdown fairly rapidly at automotive transmission and axle operating temperatures.

Duke

[Rob A.]

Re: C2 DIFFERENTIAL/POSITRACTION LUBE

Whale oil......maybe that's why this stuff absolutely "stinks". It smelled up my garage even just being on the shelf. I'll throw this stuff out and use the GM additive you mentioned.

[Duke W.]

Re: C2 DIFFERENTIAL/POSITRACTION LUBE

I doubt if what you have has any whale oil being as how whale oil products have been illegal to sell in the US for 30 years, and many other countries have similar bans.

I'm not sure what you have,but the GM lubricant and additive has functioned trouble free for me, and I don't recall ever hearing anyone else say otherwise. The differential capcacity is 3.7 pints. Start out with one 4-oz. bottle of the GM additive and fill the remainder with oil. It's best to use the minimum amount of additive to prevent chatter. Slightly underfill the diff. and if you do get chatter with one bottle add two more ounces. If not, top off the diff.

The diff is full when the fluid level is to the bottom of the plug when warm, a little lower when cold.

Duke

[Rob A.]

Re: C2 DIFFERENTIAL/POSITRACTION LUBE

Sounds good.....Thanks