NP242 Transfer Case 4x4

[OiledMustangGT]

This is a Jeep NP242 Transfer Case. It has 2wd, full time 4wd, part-time 4wd, and low gear 4wd.

manufacturer specs Dex/Mercon ATF or ATF+3

This is a heavily loaded t/c with offroading and over sized tires. Ambient temps are always 30*F+

I have heard many jeepers recommend 0w-30 or 5w-30 synthetic motor oil in the t/case over ATF. Anyone know about this?

 

[SteveD2]

I spend much of my time on about 5 different jeep boards. I've NEVER heard anyone recommend that. That would be a horrible idea. I use Mobile 1 Dex III in mine, and I hear that recommended all the time.

 

[OiledMustangGT]

yup, your on JU right?

my screen name is LouisianaZJ

 

[OiledMustangGT]

http://www.jeepsunlimited.com/forums/showthread.php?s&threadid=538834

 

[Whimsey]

If Dexron/Mercon ATF is specified why not use a good synthetic one, such as Amsoil, Redline, Royal Purple, Mobil 1. Or even Schaeffers #204S which is a semi synthetic of high quality and is less expensive than the other's. I think the chain drive transfer cases need the thinner ATF to be properly lubricated. I'm assuming that the NP242 is a chain driven transfer case. In both my Ford's I'm using the Schaeffer's 204S.

Whimsey

 

[SteveD2]

Don't use motor oil. There's no reason. Dexron is what is recommended by the manufactuerer, that's what 99% of them use. Most anything somewhat oily would probably work, but again, why not use what the manufacturer recommends? Synthetic dexron will make it last a very long time.

 

[nascarnation]

good stuff in syn Dex III
http://www.allisontransmission.com/service/autoapp172/viewpage.jsp?ThisPage=4

 

[JeepZJ4.0]

I remember JU guys recommending M1 5w30 for the 242. I have no personal experience because my ZJ is 2WD. My JU user name is the same as this board's. If "good" ol' DC says to use Dex or ATF+3, I'd be using ATF+3. ATF+3 is a real high quality fluid, more so than most JUers think.

 

[OiledMustangGT]

alright, cool

Its for an early XJ with the AW4 tranny (dex/merc), so I'll use the same fluid in both the tranny and t/c

 

[JeepZJ4.0]

quote:

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Originally posted by OiledMustangGT:
alright, cool

Its for an early XJ with the AW4 tranny (dex/merc), so I'll use the same fluid in both the tranny and t/c

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Good idea. Then I'd use the Mobil 1 Syn ATF. Is this your main off-road rig?

 

[Greaser]

Using Mobil ATF in my XJ's NP242 caused a leak between the tranny and T case.This vehicle was bought new and the fluids were done regular.The engine always had Mobil 1, axles (front and rear) synthetic,tranny (AW4 Mobil 1 Dexron/Mercon ATF)put synthetic in the T case ...leakage...dumped it out and put the usual Pennzoil ATF3 (which is used exclusive now) back..GONE...just my observation..

 

[OiledMustangGT]

How about Castrol Dex-MercIII for both the AW-4 and t/c?
Just picked some up tonight.

Also, I got a filter for the AW-4, but it is an AutoZone "brand" one. Am I safe with this type of filter?

 

[SteveD2]

quote:

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Originally posted by Greaser:
Using Mobil ATF in my XJ's NP242 caused a leak between the tranny and T case.This vehicle was bought new and the fluids were done regular.The engine always had Mobil 1, axles (front and rear) synthetic,tranny (AW4 Mobil 1 Dexron/Mercon ATF)put synthetic in the T case ...leakage...dumped it out and put the usual Pennzoil ATF3 (which is used exclusive now) back..GONE...just my observation..

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Mine has almost 200k on it, I don't know how often the previous owner changed the TC fluid, but what came out when I bought it was nearly black. (although everything else was maintained very well) I used Mobile 1 Dex III, and so far it's working great. No leaks. Haven't noticed any benefits, but then again, I haven't been looking for them...

 

[OiledMustangGT]

I dont think many people, even gear heads, change the t/c fluid very often

 

[Greaser]

quote:

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Originally posted by OiledMustangGT:
I dont think many people, even gear heads, change the t/c fluid very often

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I changed my T case once a year.Used Mopar brand ATF3 due to me getting a great deal on the stuff

then tried Mobil ATF ...the back axle was being sprayed from the T case leak...put back ATF3 in the Pennzoil brand WHAMO..gone...who knows what happened and I don't care ATF3 is all thats going in the 242 for life.

 

[OiledMustangGT]

well since I got so many great ideas from this...
what should I put in a 231 t/c on the other jeep?

 

[SteveD2]

quote:

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Originally posted by OiledMustangGT:
I dont think many people, even gear heads, change the t/c fluid very often

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Another reason to use the Dexron...my old Jeep had the ORIGINAL 13 year old fluid in the T-case, with 98,000 miles on it. Still worked fine...

 

[MariusVT]

I run the mobil 1 dex in my 231 case and it is fine. No real difference except maybe it goes into and out of 4wd a little better.

 

[SilverXJ]

I come over here from JU looking for some info on my oil analysis and I find you two from JU. LOL

 

[Sparkman]

When I drained the TC fluid at about 40k miles in my '01 XJ it looked like half used motor oil. I think the discoloration was from it getting so hot. The case was running pretty hot on the highway, couldn't hold my hand on it after driving home 52 miles from work. Filled it with Coastal Dex III and drove around for a while as a rinse, drained and filled with Amsoil Universal ATF. Haven't noticed any mileage gain, but the case does seem to run quite a bit cooler. I don't have an infrared thermometer so my account isn't well documented.

I talked to George at TCU about swapping in a 242 in place of my 231 when I first got it (before I discovered NAXJA). He said to run 5w-30 Amsoil in it. I think I will stick with ATF. I think it's more important to change the fluid often than to second-guess the engineers.