Good morning,

I was just curious as to which Gear oil to use?

When would a person want to use the 85W/140 gear oil? Is it if said person does a lot of off-roading (crawling and Forest Service Roads) and some highway / city driving?

When would a person want to use the 80/90W gear oil? Is it if said person mostly does highway / city driving with very little to no off-roading?

Cheers, and thank you

 

If you have a new truck wih fresh gears, then syn will help them last longer. Don't fall into the trap of triple the drain and replace miles. Dirt and condensation still get in there. If truck is not new, the thicker dino oil fills in some of that space already worn away by the first guy who had fun with it. The dino oil is cheaper to replace than the syn, so you won't feel so bad about changing it.

 

Hi Savannah Buzz,

Thank you for the reply.

I have been thinking about using some more ConocoPhillips lubricants which includes 76 Lubricants (Fleets and Heavy Duty), Kendall Motor Oils, Conoco (Industrial Heavy Duty), and Phillips 66 (Aviation) in their product mix. I previously worked with them, still have a good relationship and good deal on products.

Just need to decide on which one as pricing will be very close on them


Conoco Syngear SS 75W-140

Conoco Triton Synthetic Gear Lube 80W-140

76 Lubricants MP Gear Lube 85W-140

76 Lubricants High Performance Gear Oil 80W-90

Cheers, and thank you

 

Also curious which Gear Oil most are using in their Transfer Case (TC) and Diffs.

Seems some are using 75W-140 in the TC and 75W-90 in the diffs as posted here

Others recommend 85W-140 for the Diffs like this post

The 60K service list recommends 80/90W synthetic gear oil, 85W/140 for HD use...

So which would be best then across the board for TC and Diffs?

• 80W-90
• 75W-140
• 85W140

Thanks

 

Forget the 60k "list", it is a junk list.
I use 85w-140, I buy it by the gallon at Tractor Supply, I use the house brand.
I change it once a year after wading.
A full syn will not protect better, it will last longer, that is all.
Dino gear oil will last 50,000 miles under normal use in these trucks.
Use whatever you want.
It came with 80w-90 dino lube.

 

Any advantage the syn has is gone when you wade thru a creek several times and decide you need to drain the diffs that evening. And it may not last much longer, at the Rover has an open-to-unfiltered-air vent tube. So condensation, dust, wading water, insects, all can find a way in. Note - adding Lucas may not hurt, but too much and you will have a white mayonaise gunk, too much Lucas gets whipped into air fluff by the gears, and air bubbles don't lube as well.

 

Thanks Spike555 and Savannah Buzz, much appreciated

 

I used the 85/140 recently in both diffs and TC. Since it gets so freakin hot here I wanted the more heavy duty oil. This will be a once a year thing for me too. It literally took an hour to do all three. Using the heavier oil quieted down the road whine I had gotten used to. The previous owner said it whinned like that from day one. Now it's near silent.

 

I just made the switch to 85-140 as well. Its a real pita to pump it with a manual hand pump. My arm was burning and had veins popping out when i finished the diffs. TC is next then I have to do the 94. I need a better pump!

 

Is this a good option?

Thanks!



Lucas Oil Part 10062 - SAE 85-140 HD Gear Oil - 4 Wheel Parts