What to use?

[wagondave]

I will need to refill my 7 1/4 differential soon, and since it is a Sure-Grip I want to amke certain that the lube that goes in is going to be good for the plate clutches. The axle came from a '66 Dart. I recall back in the day, there was a lot of caution notes about using incompatible lubricants. I picked up a bottle of Castrol Hypoyle C gear oil which the part guy swore was OK. On the bottle it claims that it .."Meets the service fill requirements of conventional and limited-slip differentials."
My question is simply, do they know what they're talking about? Or has lube oil engineering gone that far since the last time I checked (about 30 years!)?

 

[cudamark]

As long as the gear oil is rated GL-5 or higher, there should be no problem on an early sure grip. If you find you have some chatter going around a corner, they make an additive you can add to prevent that.

 

[yellowdartdave]

Just go to the local dealer a get a bottle or 2 of Mopar Sure-Grip additive.

If it was good enuff for the factory, it is good enuff for your car.

 

[1970Duster]

Just go get yourself gear oil that has the suregrip fluid in it already.