Royal Purple 75W-90 Synthetic. I bought it 3 years ago when RP gear oil was $10 a quart. Now its something crazy like $17 a quart. My advice here is dont buy it! It does the same thing as any other fluid in the $5-$10/quart range.
Next change I'm going with Mobil 1 or Valvoline Synpower fluid that has a reasonable price.
There are many choices
I have the Chrysler 9.25 with trac lock (limited slip) Which means i need to add the hypoid friction modifier right? It has 165,000 miles on it. And im not sure if its been touched...
Ive been running some choices threw my head. From the factory my rear came with 75w90.
I can use Royal Purple synthetic which it says it has the friction modifier in it and theres no need to add any. Or i can use Valvoline synpower(Has the modifier), Mobile 1 synthetic (Has the modifier), Or valvoline (not synthetic) gear oil wich states it can be used in limited slip diffs also.
Now, should i go with 75w90? What do you guys reccomend? Should i go with Non synthetic or synthetic? Is synthetic really ok for limited slips? And is it ok to use it with my mileage?
Also, should i trust when they say that there gear oil is safe to use in limited slips and not add any friction modifier to it?
I have Valvoline Synpower 75w-140 in my truck, before changing fluid only both wheels would lock up while power braking now on a constant basis they lock up, part of this has to do with my truck being a 96' and the clutches are worn, thinking about adding some friction modifier just to see if it does anything. Valvoline says its not needed
If your truck is upside down, your mods did you no good.
I did some searching and mobile 1 synthetic is not a good choice for an LSD. (FYI) You have to add a butt load of friction modifier for it to work right..And then you still may have chatter and grabbing issues..
Ive decided im going with good ol regular 80w90 Valvoline High performance and a tube of friction modifier. That should do it problem free.
When i do this i know the fill plug is a rubber plug on the rear cover. I wanna replace this plug with a new one. Anyone know where i can get it? Got a part #? Or is it just a generic part that i can find on the shelves at an auto parts store in the misc stuff?
I am going to be adding 100% of the lucas oil additive in my diffs. It says it can be used from 50-100% and no need for limited slip additive (since there is anti foam already added to the lucas oil additive).
It is the Lucas oil "oil stabilizer"
2001 Dodge Ram 1500, 4x4 OFF ROAD California Concepts, 50mm Fastman, Fitch Fuel Catalyst, MSD 6AL & Coil, Bosch 24# injectors, 1.7s, JBA headers, Tuned by HEMIFEVER.