Yeah, I used that writeup when I did mine a while back too. It's a good one.
I recommend changing the transfer case fluid at the same time. You're supposed to inspect it when you change the diff fluids anyway, and if you go through the trouble of removing the skid plate and drain plug, why not just change the oil? Cost is less than $10.
I recommend having two different fluid transfer pumps on hand - one for the diff, one for the t-case.
I also use Mobile 1 75w90 in my front diff, but used the 140 in my rear due to towing.
I used LUCAS 85W-140 both front and rear on my 09 Rubi because I do tow now and then.Also replace the covers with G2s
1) The front differential fluid was really black and smelled like rancid ***. Is this normal?
Gear oil smells bad, but oils can actually get bacterial colonies in them to make them smell rancid. We had a hydraulic tank at work (5 barrels worth) that got infected, we had to drain it and actually use some sort of antibacterial additive to get rid of it.
My '11 manual states GL-5 and 80W90.. so that's what I bought. $15 for 3 quarts from Walmart, and 45 minutes of my time. This should be a $100 job, but if you take it to a dealer they'll rape you.
I am SOOOOOOOOOOOOOOOO glad that Jeep engineers finally took their heads out of the sand and gave us drain plugs front and rear. That makes the job SO much easier.
At 11,000 miles, I had a lot of sludge and crud build-up on the magnetic plug...though some of that could be from my new gearset. I ran synthetic fluids in the axles on my KJ and it caused chattering and noise. So I always use cheap dino fluid for the diffs now...and they are butter smooth, plus I save money. Synthetics are over-rated for gears.
'92 YJ - heavily modded
'96 ZJ - heavily modded
'05 KJ CRD Limited - 370 lb./ft. from a 4-cylinder and trail ready. Pure awesomeness.
'11 Mango Tango JKU Sport - Mods
'12 Dozer JKU Sport S - 6-speed - ACE rock rails - Max Tow package - Daystar spacers - 33x12.50 Duratracs
For me the 8 dollars was piece of mind. I used royal purple it said it had additive.
Dealer said that his book said mopar required additive in the rear even with synthetic fluid the front didn't? Take for what you think it is worth
you'll need the Mopar additive for ALL LS equipeed differentials, REGADLESS of if the gear oil you use supposedly has a LS additive/compound within. The front nor the standard open rear diff does NOTneed any LS additive.
According to mopar you still need the mopar additive even with a full syn. like moble 1or royal purple that
have an additive if you have a limited slip diff. Take it for what it is worth period. Eight ten dollars is cheaper than new gears. Hope that answers the question.
I run royal purple full syn it has a additive in it. In the front I run just it. In the rear I run the same full syn plus a bottle of the mopar additive. I have been running it for more than a year and have no problems. Hope that helps.