Diff fluid

[HoosierJeeper]

I want to change my diff fluids soon. 2 quarts/bottles per diff, right? 75w140 for the front and 75w90 for the rear? No synthetics either, right? I stopped at Autozone and they didn't carry/have the 75w140 in a non synthetic, is that a common "theme"?

Thanks!

 

[LibertyTC]

HJ from owner's manual.. poke.gif
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Capacities in metric ( ya it a Canadian thing) you can convert...
Front Diff = 1.25 Liters
Rear Diff = 2 Liters 8.25 corporate is also 75w-90 non synthetic is best
( and if trac- lok must add bottle of limited slip additive)
Transfer case is ATF+4 and 1.4 Liters
Notice the GL5 mention in 75W-140 eh...
Hope this is helpful. drive.gif :happy160:

 

[uss2defiant]

I was just reading a bunch of old diff threads.
I think you want to look for 85w-140 for dino otherwise 75w-140 is synthetic

quoting the one and only tjkj2002

http://www.jeepkj.com/forum/f202/how-change-your-front-rear-diff-oils-28670/index5.html#post560881


here are the threads
http://www.jeepkj.com/forum/f202/how-change-your-front-rear-diff-oils-28670/index5.html#
http://www.jeepkj.com/forum/f196/synthetic-vs-dino-gear-oil-48352/index2.html

 

[HoosierJeeper]

So would 85w140 be ok for both? Would that be bad given the harsher cold temps up here?

 

[LibertyTC]

^ good links..
Jeep a bit sluggish when cold takes a few minutes to warm up with 85w-140 other than that no problems, it may effect fuel mileage a bit though...
I am running Lucas 85w-140 dino in rear (I trailer stuff) with LS additive for my Trash Lokker.
Sticky stuff works well!
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Lucas has good dino in 80W-90 and 85W-140 Link: Gear Oil | Lucas Oil Products, Inc.

 

[Snail Farmer]

Yes the 85w140 is ok for both. I've had no problems running it up here.

 

[uss2defiant]

^ good links..
Jeep a bit sluggish when cold takes a few minutes to warm up with 85w-140 other than that no problems, it may effect fuel mileage a bit though...
I am running Lucas 85w-140 dino in rear (I trailer stuff) with LS additive for my Trash Lokker.
Sticky stuff works well!
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Lucas has good dino in 80W-90 and 85W-140 Link: Gear Oil | Lucas Oil Products, Inc.

LibertyTC, you've convinced me in the other threads to use Lucas. What modifier are you using?
I've got the Trac-Lok diff.

I couldn't find anything in the threads I've read but would I need the additives for the front gears?
I don't think I do.

 

[LibertyTC]

Mopar or Lubegard's LS Additive...is what I use...for Trac-Lok
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Or
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No additive for front required only rear trash lock needs it.

 

[uss2defiant]

cool Thanks.

 

[HoosierJeeper]

OK...so 85w140 it is for both. Any brands to avoid or go for? Any name brand ok?

 

[TwoBobsKJ]

OK...so 85w140 it is for both. Any brands to avoid or go for? Any name brand ok?

HJ, I've used Coastal brand from AutoZone believe it or not. It meets the GL-5 specs and it's cheaper than any of the other brands out there. Only $5.99 a quart so less than $20 to do both diffs.

Consider getting an oil pump that screws on to the top of the bottle - makes it much easier to get the oil in the diff, especially up front. It's a thick gear oil and there's no good way to pour the oil in the front diff. First time I did it I used a long tube and fished it up through the passenger wheel well to get enough elevation for the oil to flow from the bottle. Lesson learned for me that time :emotions34:

Bob

 

[uss2defiant]

what's the recommended interval for dino gear oil?
I know tjkj mentioned 15k miles for synthetic, couldn't find a post that mentioned anything specific for dino.


Thanks.

 

[renegade 04]

I would only use the synthetic stuff because it lasts longer and the long chain polymers do not break down as fast with synthetic. My dad took classes on this kind of stuff and tells me that the regular oil is not ever the best way to go and that synthetic is always better.

 

[cplchris]

inb4 everyone burns renegade04 at the stake for choosing synthetic over dino. i run synthetic 75w-140 front and rear, change the stuff every 12000 miles, royal purple brand.

 

[Mangate]

I use the Mopar oem synthetic and find it fairly easy to squirt into the front diff from the 1 litre bottles.

 

[tjkj2002]

I would only use the synthetic stuff because it lasts longer and the long chain polymers do not break down as fast with synthetic. My dad took classes on this kind of stuff and tells me that the regular oil is not ever the best way to go and that synthetic is always better.

I've taken those same classes and those high pay instructors would even admit that dino gear oil is still the better choice for diffs.Now talking about a forced oiled system(IE has a oil pump) synthetic is better but diffs do not have a forced oiled system to lubricate,they use a splash oiled system.In a splash oiled system synthetic oil has a terrible time transferring heat and why the short OCI's.Only used to gain that 0.1 extra mpg to meet federal mpg standards.Take 2 identical vehicles,put syn in on diff and dino in the other and pull there max load on the same course for 50-100 miles.Then measure the temps of the diff housings,the diff with the synthetic oil will be a lot cooler then open the diffs and temp the bearings and gears and you will find the internals of the diff using dino oil will be cooler since it's actually transferring heat better.Plus in a diff you don't want the fluid to move real freely,you want it to stay in place for longer to actually provide lubrication.


This only applies to gear oil.


But on the other hand most of your synthetic oils today are not even a "true" synthetic oil,they are just highly refined dino oil.All your Mobil 1 oils,to exclude the Extended Performance(there only true synthetic oil),all your Pennzoil synthetics,and all your Valvoline synthetics are just highly refined dino oil that meets the specs to be called synthetics in the US but the more highly refined the less able to transfer heat in a splash oiled system.

 

[uss2defiant]

so what is a sufficient dino gear oil change interval?

going off the wiki, it mentioned 20k. is 20k on dino gear oil sufficient?
Thanks.

 

[tjkj2002]

so what is a sufficient dino gear oil change interval?

going off the wiki, it mentioned 20k. is 20k on dino gear oil sufficient?
Thanks.

About 50k if you wheel it(check after each trip through any water,change if needed) or tow.100k if you just daily drive it without wheeling/towing.




Oh on a side note Currie who made my rear diff(RJ60) specifically states "DO NOT USE SYNTHETIC GEAR OIL",came with a big sticker on the diff cover.A high end diff that cost over $4k and they want me to use the "cheapest 85w-140 GL5 gear I can find" and that is what there tech said when I called and confirmed.The pinion bearings would be totally shot if I use syn oil in less then 200 miles.Hi9 which also makes high end 9" center sections for ********* wheelers also warns only to use dino gear oil,it's in ********* text on there website on every page it seems.

 

[tommudd]

I've always ran dino and change about every 50-60,000 miles
Its cheap, its easy, it smells oh so good :icon_lol: plus I pull a trailer a good bit so change it more than some I suppose

 

[LibertyTC]

Oh ya Tom it smells so good..:signs16:
With My Trac-Lok I wont let it go to 50K.
I like to see if I got clutch matter in there!
I think 20-30k is a good time to drop cover off & have a peek in there and change it anyways.
Then I feel good about :driver: the KJ again. :icon_lol: