Cummins LSD special oil???

[Rot Box]

Well I'm making the switch over to Royal Purple Synthetic oils in my 92 Cummins, and I have a question about the rear diff.

It has the standard 4.10 Dana 70 with the limited slip. The LSD works great, but don't they need some special fluid/oil when servicing them? If so what should I look for? Would this be the typical clutch pack style or something different? I'm sure the stealership has what I need but is there a better option? Thanks for any help

Andrew

 

[muddyjeep]

Friction modifier

You need to go to an Auto parts store checker, Auto zone, ect.
And ask for Limited slip additive. It comes in a little tube
and is only a few bucks.

 

[1993yj]

Before spending anything on the LS additive, I would consult your owners manual. For a '92 you probably need it, but I would check first. I used to have to put it in the rear of my '95 Wrangler when it had the factory limited slip, and I still add it to my front with an ARB, but in my Dodge, I have the factory LS in the rear, and my manual specifically says NO LS ADDITIVE.

 

[Rick B]

I haven't heard of any gear oil that doesn't already have the friction modifiers already installed, but you should check. My locker doesn't need it and I've never had a vehicle that did.

 

[Rot Box]

Well I'm all switched over to Synthetic except for the rear axle. I guess I better call the dealer, and see what they have to say. I hate doing that because most of the time they don't know either and they might say I don't need it when I do or vise versa Anyway thanks for the reply's

Andrew