2nd Gen Non-Engine/Transmission limited slip synthetic lube

[BFrye]

Will synthetic lube be harmful to a limited slip? I have heard that it does and that it does not. What is factual?

 

[LHastings]

With only my personal experience with synthetic lube my clutch pac wore out within 30,000 mi. I went back to dino lube now with over 250,000 mile with normal oil change intervals the clutch pack is still good.

 

[fest3er]

I put Amsoil in my differentials at about 90k miles, back around 2001. I still drive the truck today, at almost 300k miles. Diffs haven't been touched, though the rear's far from perfect. Its bearings were growling at 30k miles and there was ring and pinion wear back then; everything's worn more since.

 

[JR]

Synthetic 75w140 is recommended in the Dana axles for heavy towing.

http://dodgeram.info/tech/BRSpecs/fluids/specs.html

Disregard the recommendation for 75w140 in the front axle, it is a misprint. I contacted them over it a few years ago and pointed it out but they never changed it.

 

[GAmes]

My D80 with LS is the only original piece in my drivetrain. Other than a pair of seals about 500,000 miles ago it has performed flawlessly, and I had an opportunity to test the LS not too long ago. I have been using synthetic since the first lube change and nothing but Royal purple for the last million miles. I can not think of one reason why a synthetic oil would cause a part to fail.

 

[Joe Mc]

I think, and although "there I go again" I could be wrong, the key to a healthy LS clutch pack regardless of type/manufacturer of the lube being use (as long as correct weight) is utilization of the correct amount and type of recommended friction modifier with each oil change and doing 8 to 10 figure 8's to mix in and make certain the clutches receive the new mixture. My $0.02.

 

[GAmes]

I've never even done one figure eight after changing the differential oil, much less 8 to 10.

 

[Joe Mc]

GAmes, to each their own. Just sharing what I've read as being the "recommended" process. For sure it can't hurt. You like your Royal Purple others might like their fragrant orange. Correct type and amount of friction modifier is, undoubtedly, the key here. Gesh

 

[RustyJC]

I ran Royal Purple 75w-140 synthetic in my 2002 3500 ETH/DEE. The RP came with friction modifier formulated into the lube, and no additional friction modifier was required. It gave excellent service towing our previous 16K GVWR Mobile Suites 5th wheel.

Rusty

 

[KATOOM]

Its funny that even today we still hear of people who think synthetic oils are some magical space goop fabricated only by men in white lab coats in a top secret government laboratory. :-laf Its just the best stuff pulled from the crude petroleum oil cracking process with various proprietary additives.....and is FULLY compatible with all other conventional fluids. No harm to any differential by running synthetics, LS or not. And most synthetics already contain friction modifiers in their recipe so typically no more is necessary.
But this isnt to claim that everyone needs synthetic fluids either as todays conventionals are worlds better that they were. Do your research and use what you think is right.

 

[fest3er]

That's one method; it results in a more consistent collection of molecules, but still not as consistent as oil synthesized from uniform small molecules.

The other method is fully synthesize the long-chain oil molecules from small molecules, resulting in a very consistent oil that has few light molescules that will evaporate and, thus cause the lub to thicken over time.

A fully synthetic lube with carefully chosen, high quality additives lasts longer, remain 'liquid' at much lower temperatures, maintains its viscosity longer, and generally lubricates much better than 'similar' lubes created through fractional distilling methods.