Sure-Grip lube

[bronze turbine]

What does the additive actually do? I just bought some limited-slip gear lube from NAPA that says it's ready to use right out of the bottle--no additive needed. Can this also be used in a non-Sure-Grip diff?

 

[Ross Wooldridge]

I had to renew/replace the fluid in the wagon's Suregrip, and although I specified Mopar additive, the mechanic installed a "no additive required" fluid and said I wouldn't need it.

Unsatisfactory. Chattered on every turn.

Added the Mopar Suregrip additive and the problem went away.

Something to do with the clutch material, but I don't know how it works with cone type units.

All I know is that I'd recommend using it.

 

[Toolmanmike]

Dr Diff. Friction Modifier. He sells Motorcraft but that's ok.

 

[CBODY67]

I suspect that ANY limited-slip differential which has spring-loaded clutches, which are "locked until they unlock" will NEED the friction modifier additive (by any name or OEM) to work smoothly in turns. Others, unlocked until they lock, can use the "other" limited slip fluid as is. if the "unlocked until they lock" limited slip differential chatters or otherwise, then it needs the additive too. Some appliactions might even need TWO bottles of additive to keep things quiet and smooth.

CBODY67

 

[rags]

Motorcraft

i would use two of those in the dana 60 fords i would do. sometimes it worked. sometimes not. when they would chatter with the modifier i would pull the clutches back out and smear them with bearing grease. finally figured out that if i coat the clutches with modifier before assembly they would be good every time.

 

[SIPLOWGUY]

I worked at a Pontiac store in the 80's. We would drive the car in figure 8's after a limited slip rear service. That would work the additive in to the clutch plates.

 

[68 4spd Fury]

Full synthetic lube has the modifier, (or an equivalent), built in. How these will apply to an axle designed and built 50+ years ago is another matter. Personally I'd stick with the FSM recomendations.

 

[Timmayy]

Dr Diff. Friction Modifier. He sells Motorcraft but that's ok. View attachment 606514

Yup. This is what I used in my 68 RR 8 3/4 sure grip.

 

[70bigblockdodge]

The additive just works better.