What weight gear oil???

[AKDrifter]

^^^
So 40,000 miles or 4 years for the axles and 6/60 for the transfer case under severe use.

Yes it's not very frequent. I do my T-case the same time as I do my transmission fluid though every 2 years. Mine will be due for it again in October. I didn't realize until I was almost at 30k miles that you even had to change the transmission fluid but you do on the 6 speeds. I do the axles every October unless I have done a deep water crossing and then I'll change fluid then. Always handy to have some squeeze bags of Severe Gear handy.

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[alpineovernappa]

Interesting that it only stipulates to change the diff fluid for "police, taxi, fleet, offroad and trailer-tow" applications. One could argue this verbiage suggests the gear oil is otherwise implied to be a lifetime fluid with no maintenance interval. (There is no such thing as a lifetime fluid, I'm not saying to neglect maintaining your diffs)

 

[Hootbro]

Interesting that it only stipulates to change the diff fluid for "police, taxi, fleet, offroad and trailer-tow" applications. One could argue this verbiage suggests the gear oil is otherwise implied to be a lifetime fluid with no maintenance interval. (There is no such thing as a lifetime fluid, I'm not saying to neglect maintaining your diffs)

Like the "Lifetime" transmission fluid fill. More marketing to get you past the warranty and for them to advertise a lower maintenance cost.

 

[ShadowsPapa]

Yeah, but big differences between automatic transmission fluid and hypoid gear oil.
Until I started digging in Jeep forums, I never ran across anyone who changed differential lube at anything less than 100,000 miles, and even towing, it was not a frequent thing.
It seemed to be mainly a "Jeep thing". We never once had anyone come in and request differential fluid service other than check and add as needed.
Wreckers got different treatment, but pickups? Just didn't happen.

 

[GladiatorMax]

Ok, so I have a 2021 diesel Jeep Gladiator Rubicon. It doesn't have a two package per-se, but it is able to tow up to 6,000 and comes standard with a hitch receiver and electrical connections. Everyone on here says 75W140 for the rear axle, but my owner's manual only calls for 75W85, it doesn't even mention the M200 sales code for the rear axle.

Where is everyone getting the 75W140 for the rear axle from?

 

[AKDrifter]

Ok, so I have a 2021 diesel Jeep Gladiator Rubicon. It doesn't have a two package per-se, but it is able to tow up to 6,000 and comes standard with a hitch receiver and electrical connections. Everyone on here says 75W140 for the rear axle, but my owner's manual only calls for 75W85, it doesn't even mention the M200 sales code for the rear axle.

Where is everyone getting the 75W140 for the rear axle from?

I use Severe Gear 75-90 and always have. Maybe if you tow more than you don't I'd go to something thicker. People going with a thicker oil probably are just used to doing so, I doubt it'll hurt anything except maybe a fraction of a mpg.

 

[kevman65]

Ok, so I have a 2021 diesel Jeep Gladiator Rubicon. It doesn't have a two package per-se, but it is able to tow up to 6,000 and comes standard with a hitch receiver and electrical connections. Everyone on here says 75W140 for the rear axle, but my owner's manual only calls for 75W85, it doesn't even mention the M200 sales code for the rear axle.

Where is everyone getting the 75W140 for the rear axle from?

If nothing else, O'Reilly Auto carries 75W140. Do yourself a favor and get the Valvoline in the squeezable pouch.

 

[g2020]

Ok, so I have a 2021 diesel Jeep Gladiator Rubicon. It doesn't have a two package per-se, but it is able to tow up to 6,000 and comes standard with a hitch receiver and electrical connections. Everyone on here says 75W140 for the rear axle, but my owner's manual only calls for 75W85, it doesn't even mention the M200 sales code for the rear axle.

Where is everyone getting the 75W140 for the rear axle from?

Here's a list of online retailers from section 4.1 of Links to Prices. In the gear oil table in section 1.3, the brands available off the shelf are linked to Walmart.

Advance Auto Parts
AMSOIL
AutoZone
MOPAR eStore (official MOPAR online store)
O'Reilly Auto Parts
RED LINE SYNTHETIC OIL
RockAuto
ROYAL PURPLE DIRECT
Summit Racing
Walmart

 

[ShadowsPapa]

If nothing else, O'Reilly Auto carries 75W140. Do yourself a favor and get the Valvoline in the squeezable pouch.

Yeah, stick with that or the MOPAR stuff to be safe. Valvoline in the pouch is a preference (good price, good product).

I avoid almost all of the others based on observations of experiences of others have had with them, and test ratings from independent sources.

Sometimes people love a 'name' but the name doesn't mean each product is "best of class".

 

[ShadowsPapa]

It means that each option was carefully screened.

 

[Lost1wing]

No offense, but you ain't gonna like this -

You aren't servicing it. You are only changing most of the fluid and really have no idea what condition things are inside.
Trying to keep yourself and the floor clean isn't doing the truck any favors.
Amazing how people scream about a drain plug and think that dropping fluid and putting new in is some right of passage, a big feat, and yet there's a reason the cover is so easy to take off, and reseal without a lot of effort.
Real servicing is more preventative maintenance and inspection. Drain it, pull that cover, use your hand (yes, get dirty) or if resistant to that, make a scraper from the side of a milk jug and scrape out every bit of fluid you can. That's where the real dirt is, and that's where you truly learn about your differential.
Look for stuff in the bottom (because the drain plug won't really get all the fluid out, let alone things that may have settled there from bad bearings or gears)
Inspect the patterns on the ring gear. Look for galling on the side and spider gears. Look for chips, anything unusual, clean it out good, then button it back up.

BTW - I suspect Dana got the reusable cover gasket/seal from AMC when AMC sold Dana their differential designs years ago. It was so nice servicing the AMC 20s - no drain, pop the cover, clean it out well, leave nothing in the bottom of the housing, inspect things, put the cover back on, refill it.

No offense - but I gotta ask the general population -
changing diff fluid almost seems like a right of passage - some thing you do when 13 to become a man and yet no one bothers taking the cover off (well, very few) and yet are so concerned about changing fluid way early - because friends say it's the right thing to do and you are a better Jeep guy if you do.
So, why not pull the cover?
Why the fuss over a plug when you SHOULD be pulling that cover every time you change the fluid so you can visually inspect the gears, wear pattern, side gears and spiders and so on, and see what crud lays at the bottom of the housing - crud that will not drain out by pulling a plug.
My take (today anyway) is that Dana did us all a favor by taking that drain plug out - not you must truly service it and inspect things an you know exactly how your differential is wearing in and what condition things are in.
You can't tell squat by pulling a plug and dropping what fluid out that will come out. Only if you see glitter and pieces - but by then it's too late., Had you pulled the cover LAST time and looked inside, you may not be seeing glitter this time because you'd have seen and fixed the problem.
Preventative maintenance is visual inspection, not just dropping fluid and being thankful you did't get dirty.
No, DANA/Jeep, did us a big favor by taking that plug out regardless of the perceived reason or opinions of the reason. They forced true preventative maintenance and visual inspection.

I always pull covers off - and always have - since the early 1970s every differential I have ever done anything with - the cover comes off. And I've been thankful in I do that in a couple of cases. I found things that indicated damage I would have NEVER found had there been a drain plug (and most do not have drain plugs - it's really not a common thing to have a drain plug in a differential that has a removable cover)


If you care, which you claim by saying you changed the fluid and do it every 5,000 miles, then you will actually pull that cover. Get dirty. Buy a big galvanized water pan or a large oil pan to let 'er drop into as you pull that cover. Go get a cheap air ratchet to make it go really fast.

I pulled the cover on my CJ5 Dana 23 and was shocked I didn’t notice anything wrong while driving. King pins were the reason for disassembly. That axle never saw the road again. The spider gear pin had wore out the carrier. The carrier bearings were shot too. All of that from a failed king pin bearing that was ignored for years of use( abuse).

Yeah, I'd open it up to have a look .

 

[OldButStillJeeping]

Man, you guys are dedicated and have way more time than I do. Kuddos to you all.

And, I am not saying any of you guys are wrong, keep doing what makes you happy... But:

I do the diffs and TC fluids every 40K miles on all my 4X4s. Including my JT. I have done it that way for decades. I have personally rebuilt diffs to change gear ratio or add lockers and limited slips.. And rebuilt transfer cases to swap out the final drive to SYEs. So I am no newbie to the pumpkin world. But, I am not a pro axle builder either.

I do not do water crossings as a habit and a rule. Period. If I have to, the fluids all get changed.

I have never had a failure. I simply look for shiny bits in the fluid, and if not, replace the cover, (or put the drain plug back in), refill and go.

If your differential starts making noise, then sure, look into it.

And...
This 1/8" below the fill plug thing. LMAO. I fill it until it starts to drip out and replace the plug. Done. It's pretty silly to do otherwise. The slosh and air bubbles and such make this 1/8" thing pretty silly. Unless you want to lift a tire and spin a wheel and let it settle for an hour. I guess some over-educated under experienced nerd engineer with connections higher up, came up with 1/8" below crap. "Hand me your pocket protector and grab a wrench, Moron". The fill hole was put there for a reason.

Todays fluids are better than ever. And through the history of solid axle differentials, most people NEVER changed the fluid. Not that you should do that, but I am just sayin'. When I was 17 y/o I bought my 71' Toyota Land Cruiser FJ40. I was changing the diff oil in the driveway and my dad came home from work and asks me what the hell I was doing. I told him. And he laughed. He said something like: "No one does that, but waste your money if you want to. If it leaks, or makes noise, fix it and do that, otherwise that oil will last longer than your Toyota".

I am not saying my Pops was right. I am just saying that it's usually a non-issue.

But, Keep up doing what makes you feel happy. I will do what has worked for me for over 4 decades.

Be well. Jeep on.

Eric

 

[Hootbro]

Where is everyone getting the 75W140 for the rear axle from?

You will not find it in the owners manual. It is mentioned in the Techauthority service data the dealerships use for vehicles equipped with the tow package. DANA also calls out that grade when their axles are rebuilt and is what they ship their aftermarket sold axles with.

Owners manual is only going to list the fluid grades they obtained their MPG certifications with and nothing else.

 

[ShadowsPapa]

I have never had a failure. I simply look for shiny bits in the fluid, and if not, replace the cover, (or put the drain plug back in), refill and go.

Yup - it's your vehicle and you've had luck that way. In over 50 years I've had enough of them with no "shiny bits" coming out, including my own, which made NO noises, I pull covers. It's a few moments of time.
When I find chunks in the bottom, things that will not come out a drain plug, I start digging. And I'm really glad I did.
The carrier bearing in my car that was missing a small piece of one of the rollers actually looked good when I pulled it - there wasn't wear, the race wasn't galled. There would have been no evidence without my scraping the crud that settles to the bottom of every differential housing (that is missed with a simple drain and refill).

I guess we can only go by our own experiences. Mine have taught me to pull cover, scrape out the crud and inspect, your experiences have shown that at least on those you've done, there wasn't a reason to.

 

[OldButStillJeeping]

Yup - it's your vehicle and you've had luck that way. In over 50 years I've had enough of them with no "shiny bits" coming out, including my own, which made NO noises, I pull covers. It's a few moments of time.
When I find chunks in the bottom, things that will not come out a drain plug, I start digging. And I'm really glad I did.
The carrier bearing in my car that was missing a small piece of one of the rollers actually looked good when I pulled it - there wasn't wear, the race wasn't galled. There would have been no evidence without my scraping the crud that settles to the bottom of every differential housing (that is missed with a simple drain and refill).

I guess we can only go by our own experiences. Mine have taught me to pull cover, scrape out the crud and inspect, your experiences have shown that at least on those you've done, there wasn't a reason to.

Yes Sir.

But a failed bearing, especially in the pinion or carrier, would usually make some noise. Even to the uninformed. I am glad that you found it ahead of time. Cleaning the bottom of the diff is never a bad thing. As you found out.

Preventative maintenance, definitely has it's benefits.

Cheers

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