Sure-grip/Posi fluid and gear oil.

[moparist]

I'm working on my 65 Coronet with an 8.75 rear axle. I have two pumpkins for it. One is a 741 w/3.23 gears and a clutch-type sure grip. The other is a fresh-built 489 case w/3.55 gears and an Auburn-type posi unit, fresh from Randy's R & P. Back in the day, you could go and buy generic "Posi fluid". Now you need to buy the 80-90 gear oil and put in some additive. I went to the local Car Quest and they have the gear oil and additive. The parts guy also said he has 80-90 synthetic oil with the additive already in it. What do I need to put in the rear end (Coronet's) to make each/both work as advertised??? I'm so confused

 

[Photon440]

What does Randy's recommend for their pumpkin?

 

[shag766]

What does Randy's recommend for their pumpkin?

X2

 

[moparist]

I posted this query on Sunday nite and Randy wasn't accepting calls. I meant to call them Monday and didn;t get a chance. I called today and left a message and they'll call me back in the next few days. I have an 8-inch Ford with an Auburn unit and Currie recommended 80-90 with the GM-type additive. I also e-mailed a buddy who's a retired Chrysler mechanic but have no reply yet.

 

[moparist]

:hello2: Just heard from Bruce at Randy's R & P. Their recommendation is to use the regular 80-90 wt oil with a bottle of the Ford Performance or Yukon additive. He says it works with all posi and sure-grip units. So I can use it with either of my chunks regardless of who made the traction adder.

 

[Cranky]

The TracLock in my 9 1/4 rear chattered badly after doing a lube change (reason for the change) and it still chattered after the new oil and dealer supplied additive went in. Drained it again, added new lube but this time it got the same amount of STP. It's been fine since. Go figure!

 

[moparpoor]

I have used the ford whale oil for many years successfully.