Does Royal Purple's rear gear oil have enough of a slip additive or will I need to add in addition to it?

[Mister Lamb]

Gearing up to replace front and rear diff fluid. I'm just curious how much of the slip additive is required and if these fluids (like Royal Purple) which have the additive already included contain enough?

I only ask because because I read a review of Valvolines gear oil and how they experienced clunking post fluid change until they added additional slip additive.

Thanks

Sponsored

 

[Janster]

Gearing up to replace front and rear diff fluid. I'm just curious how much of the slip additive is required and if these fluids (like Royal Purple) which have the additive already included contain enough?

I only ask because because I read a review of Valvolines gear oil and how they experienced clunking post fluid change until they added additional slip additive.

Thanks

Granted, I’m old school and things have probably changed….

Do you have an LSD rear? Friction modifiers used to only be needed for LSD or anything with ‘clutch type’ devices. My husband used Royal Purple in his corvette - which had an LSD in the rear.

I wouldn’t think the Rubicon / Mojave Lockers (or open diff) need any friction modifiers. But then again…this is ‘old school’ thinking and Jeep probably recommends it for what ever reason. So, I’m here to learn….

 

[Mister Lamb]

Granted, I’m old school and things have probably changed….

Do you have an LSD rear? Friction modifiers used to only be needed for LSD or anything with ‘clutch type’ devices. My husband used Royal Purple in his corvette - which had an LSD in the rear.

I wouldn’t think the Rubicon / Mojave Lockers (or open diff) need any friction modifiers. But then again…this is ‘old school’ thinking and Jeep probably recommends it for what ever reason. So, I’m here to learn….

Willy's package includes rear LSD, yes. Not sure about which other models do or don't to be honest

 

[bd100]

Usually ok as-is. Change it and do some figure-8s in the parking lot and see what happens.

 

[redfish]

I have a limited slip and did add additive with the royal purple

 

[g2020]

From Royal Purple:
"Formulated with a friction modifier additive, therefore no additional additives are necessary."

 

[Mister Lamb]

From Royal Purple:
"Formulated with a friction modifier additive, therefore no additional additives are necessary."

Valvoline makes the same claim but some ppl reported needing to add after the fact. I'm just gonna throw an ounce in with the Royal Purple

 

[wolfdog]

If you have LSD it will be only in rear diff, front does not require additive!

Go Jeep!!!

 

[bd100]

I guess I should clarify that when I said to do figure-8s in the parking lot, I meant to drive slowly turning each way listening for knocking sounds from the back. Going left/right/left/right helps mix the stuff into the clutch plates, and doing this a few times can stop the clunking.

Of course, doing smokey burnouts left and right would be more fun(!), but then you couldn't listen for the diff knocking.

 

[Blade1668]

Gearing up to replace front and rear diff fluid. I'm just curious how much of the slip additive is required and if these fluids (like Royal Purple) which have the additive already included contain enough?

I only ask because because I read a review of Valvolines gear oil and how they experienced clunking post fluid change until they added additional slip additive.

Thanks

I've always added it in my Jeeps that have Trac-Loc's no matter if the gear oil says it has additives for it. I keep a tube on hand for it. At least 3 axles I have are still working fine. One has over 255k on it.

 

[ShadowsPapa]

Valvoline makes the same claim but some ppl reported needing to add after the fact. I'm just gonna throw an ounce in with the Royal Purple

What people? What vehicle?
There are multiple types of "limited slip".

I've used Valvoline without issue in various types from old to new. Never an issue.
I've not used an additive in decades.

I don't use RP anything, sorry, can't speak to it other than my personal reasons.

 

[Hemy5587]

I used the Mopar limited slip additive when I used Valvoline on my rear differential. I could feel it binding up in parking lots/turning tight. It is cheap and easy insurance also beats having to take some new differential fluid back out just to add the additive in.

 

[WILDHOBO]

What people? What vehicle?
There are multiple types of "limited slip".

I've used Valvoline without issue in various types from old to new. Never an issue.
I've not used an additive in decades.

I don't use RP anything, sorry, can't speak to it other than my personal reasons.

I’ve been using Valvoline 75x140 in mine since it was regeared w/ 513’s 63k miles ago. I recently had the rear redone with new bearings and shims as normal maintenance after a rear axle break. The ring and pinion both looked brand new after those hard miles. No extra additive for me.

 

[ShadowsPapa]

I’ve been using Valvoline 75x140 in mine since it was regeared w/ 513’s 63k miles ago. I recently had the rear redone with new bearings and shims as normal maintenance after a rear axle break. The ring and pinion both looked brand new after those hard miles. No extra additive for me.

That's my choice for these axles, and the axles under my cars as well.

 

[Mister Lamb]

What people?

The guy who posted directly after you and this guy on Amazon. So 2 ppl required an additive due to a clunky diff post valvoline oil fill and 2 did not in this thread alone. Not everything is black and white it seems

Sponsored