Engine/Transmission (1998.5 - 2002) Best Synthetic 90W-140 for towing?

[Texas Diesel]

Any favorite lubes you have had good success with? Valvoline synthetic is $13/qt :-laf



Royal Purple is around $9; any other suggestions?

 

[DHayden]

I have been running the Royal Purple for some time now and I'm happy with it. Temps are never an issue, no chatter and I don't have to add friction modifiers.

 

[LandShark]

Mobile 1 is another choice that I use. A bit hard to find sometimes.

 

[RustyJC]

I've been running Royal Purple since about 4K miles. It's worked just fine towing our 16K GVWR 5th wheel in ambient temps up to 105 degF - no supplemental friction modifier was required for my truck's limited slip.



Rusty

 

[Supermod56]

I use Redline Lightweight Shockproof in my Dana 80, works great, and about 10 bucks a qt. It's comparable to 90-140

Tom

 

[Texas Diesel]

I've been running Royal Purple since about 4K miles. It's worked just fine towing our 16K GVWR 5th wheel in ambient temps up to 105 degF - no supplemental friction modifier was required for my truck's limited slip.



Rusty

What weight are you running?

 

[Gary - K7GLD]

I wanted a heavier weight lube for my LSD differential that still provided proper limited slip function - I tried Amsoil first, but it was too slippery, and rendered my LS clutches inoperative. So I next tried Valvoline synthetic blend - it provides the heavier duty protection, at least some of the added benefits of the full synthetics, and best of all, my LSD still works fine with that lube right out of the bottle.



Guys wanting to experiment with "better" differential lubes, and who are also needing their LSD's to still function as designed, would be well advised to check out that function after driving a few miles with the "better" stuff to make sure they haven't provided more of a problem than a "fix"...



You'd be surprised how many owners out there have switched lubes, and THINK all is "better" - and have no clue that their LSD isn't working any more...

 

[DHayden]

I run the heavy weight RP and my limited slip works perfectly. I test it at least a few times a week on the gravel driveway on the side of my house, 4 nice clean strips of dirt :-laf

 

[RustyJC]

What weight are you running?

85W-140. And, yes, my LS is working just fine.



Rusty

 

[Okie-Go]

I put Royal purple in mine today. I had no problem with the amsoil that was in there for close to 130,000 miles but found the rp here in town and didn't have to order it. I got the rp for 6. 99 a qt. I took out the lsd and put in a locker!

 

[Diesel Nut]

Love my Severe Gear Amsoil! No temps on this truck, but my old truck was cool with amsoil. Severe gear is 9. 50 qt. Basic gear oil is less.

 

[MRose]

I just put texas refineries red in. Any other experiences with it?