2nd Gen Non-Engine/Transmission Differential oil

[RClark]

@002, 3500, 4:10. Limited slip and Mag-Hytec cover.

What is the best aftermarket oil to use?

what weight should I use as I haul a 13,000lb trailer most of the time?

Should I use the limited slip special lube if the oil is synthetic and says it is not needed?

i have 36,000 on the rig ans 12,000 on the dealer lube in it now.

 

[Extreme1]

Opinions vary but I like Amsoil.



Use the weight specified by your owner's manual. In LB you can probably run the heavier option.



When you put the new oil in, don't add the additive. It seems to be vehicle (not oil brand) sensitive wether you'll need it or not.



After the lube change, go to an empty lot and do a couple dozen figure 8's. If you need it you'll feel a binding in the rearend. Add the Mopar brand additive 1 ounce at a time until it stops binding. (do more figure 8's to work it in).



FWIW - It may take more than the initial figure 8's to get it to bind up if it's going to do it.

 

[rweis]

My 2002 manual says use a synthetic if you are going to tow.



I use Royal Purple. When I changed I did not tip the axles on each side to get all the OEM lube out, my mistake.



The residual slowly will adhere to the dip stick and I wiped it every weel for about 6 months to finally get all the black sludge out. Now dip stick is clean. I check it a every oil change.



Don't forget to tip the axles to get all the old stuff out.



Bob Weis

 

[Dane]

Oil discussion - yikes!

There are many good brands of diff oil out there. I think it's much more important you change it every 10K if you haul most of the time than which brand you use.

 

[Diesel Gunner]

I tow an 11K TT. I currently have LE607 in the axles. On the next change I am going to put Delo ESI 85-140 in the rear axle due to the high temps I have seen while towing the TT in the summer when it is very hot outside. Temp has gotten as high as 210. I know that this is not in the danger zone, but what I have seen with the Delo is simply amazing. I also want to go to the higher viscosity and the LE is 80-90. I have no negative comments to make about the LE, I am just very impressed with the Delo.

 

[mhenon]

I tried a synthetic blend by Valvoline. As recommended by the manual I'm using an 80W/140 for towing. It looks good after 30k miles towing and didn't need any friction modifier for the limited slip.

Mike

 

[cyborg]

Royal Purple and regular changes works for me.

The label on RP say no friction modifier is needed, but I add it any way. And I use it my boat.

I swear I notice the difference.

 

[Turbo Thom]

I've used the Amsoil W140 for about 40K miles, as per recomendations, and have found the rear gears to heat up slower but still get up to where the 75W-90 ran. I stay at 180-190 degrees, towing . Empty----180. Maybe more lubrication but not less heat. I used the 75W-90 for about 100K miles, tow all the time and for me, I like it a little better. The rear end cools down quicker after a run on the highway. With the 140, the temps stay hotter, longer.



Fricton modifier... . I use one bottle. 299K miles and it still goes on down the road.



. . Preston

 

[storm'in]

Torco 85W-140 Synthetic Gear Oil

Have any of you guys tried it? I've been using it for years in dirt bikes and have had good luck with it. And a local shop carries it in stock. It also has the friction modifier in it.

 

[JGheen]

Why would you need the friction modifier? I just replaced my oil the other day since it started leaking out of the blue. Pulled the cover, cleaned all the old RTV off, put some new stuff on and no more leak. The oil looked good after about 50K. Had the typical golden shine to the oil. I used some Valvoline 75w-90 and I couldn't believe the damn axle took 4 quarts! No friction modifier added and it seems to be running just fine.

 

[Gary - K7GLD]

I also use the Valvoline synthetic blend 85/140 - my LSD works perfrctly with the Valvoline as it comes outta the bottle - Amsoil and other synthetics are good lubes - but CAN cause the LSD clutches to become non-functional and loss of LS function. As stated above, these differentials vary greatly in characteristics from one to another - so what works for one may not work the same in another as far as the LS is concerned - and the heavier weights are a must for towing, as my Ford RVing bud is learning today - he used the plain 90 wt. stuff, and is getting a differential rebuild in his '99 at a cost of about $1200... .

 

[JGheen]

Well, I hardly ever tow anything, pretty much almost never. Just take the rig off-roding quite a lot. I think the 75w-90 will do me justice enough... ...

What about the friction modifier, why would one need to use it? Is it mostly for those who consistently tow something?

 

[Diesel Gunner]

OK. Here is the skinny on weather one needs to add friction modifier or not. I am most familiar with the Chevron product and will use them as an example.



Chevron RPM Universal Gear Lubricant in 80-90 or 85-140 would more than likely require the addition of friction modifier when used with an LSD. If one were to use Chevron Supreme LS Gear Lube, then, most likely there would not be a need to add friction modifier.



The reason why? The Supreme LS product has the modifier and the RPM product does not. How does one determine this? Contact the manufacturer. Any manufacturer can be contacted somehow and asked "Will I need to add friction modifier when I use your lubricant in application XYZ?" They will have a recommendation. IF they don't seem to know. Move on to the next manufacturer.



My point here is that some of us may not need modifier, either because it is in the lubricant that we are using, or our particular application (differential) is just not set up tight enough to cause chatter, or works just perfectly without the need for it. Or, any combination of the above and probably some more that I have not mentioned.



Still in warranty and care? Use the recommended lubricant. Out of warranty or you are your own warranty station? Use what you find works the best for you. Me? I will be using the product that I mentioned above because of what I have seen. My hope is that in 300K I will still feel the same about it as I do today. We shall see.

 

[Lube Man]

Reducing gear temp

It is a misconception that increasing oil viscosity will lower temperature. Just the opposite is true. To keep gears in a gearbox running cool you want as much oil flow through the gear mesh as possible. The lower the viscosity, the greater the flow. (Especially in a forced feed system). However, the oil must be of the proper viscosity to maintain a proper film under load.



Also bear in mind that the higher viscosity oil reduces MPG. Again, more of the energy from the engine is going into producing thermal energy in the gearbox.



If gearbox temp is lower with lighter oil it is an indication that a proper oil film is being maintained. I would stay with the lighter oil. Also use synthetic. I can operate at higher temps than conventional oil before breakdown occurs.

 

[enes]

i just put the redline heavy shock proof...



that stuff is super thick, and i am not sure if i like it yet, i only put about 100 miles so far. It doesn't need any lube gear since i went and did like 10 figure 8's 3 times in a row and there was NO chirp or notchiness.



I will most likely remove half of it and some of the just regular shock proof stuff from redline to maybe cut down on the thickness of the oil. because the fluid i removed was very very runny. .



-E

 

[RobertMiller1]

redline

ah. . shockproof is the finest. but it does come in 3 weights. sounds like you went with the heavy. Fine for very heavy constant hauling, but lightweight 75w90 would probably be a better daily commuter/mileage oil