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Discussion Starter · #1 ·
Has anyone ran 5w30 Mobil 1 in there transfer case instead of trans fluid I run it in my Duramax transfer case no prob.
 

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What t-case do you have? Regular or the 4Auto t-case? The 4Auto case has clutches in it so I would be very nervous about putting anything but trans fluid in there.

Either way, why? The fluid isnt THAT expensive and I don't remember the t-case taking all that much fluid. And if you don't wanna run the Mercon you can run Valvoline. They have a fluid that can replace the Mercon LV and another to replace ULV.
 

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Discussion Starter · #5 ·
It’s a 2018 3.5 none auto 4x4 just seems motor oil is a little better than thin trans fluid. Like I said been running it in my Duramax no prob just wondering
 

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Eh. I dont think you are gunna find anyone here that has done it. I wouldnt personally. Or if I did use something besides trans fluid I would be looking at a light gear oil or maybe manual trans fluid.

These t-cases are not known for crapping the bed unless someone is tuned doing 4x4 launches at 3000 rpm.
 

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It’s spec’d to run the trans fluid, by swapping to motor oil you may not have a problem, but you also could cause an issue.

I personally wouldn’t risk it.


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Just went thru this with an ol manual box. T19 In my Scout. Was having synchro issues in going into 4th. Was running dual weight oil 20w50... Wasn't cutting it when not up to temp. Just switched over to Lucas SAE 50 plus. And it runs much better.

I'd run what is spec'd. It's cheap. Oil and it's like a whopping 2 qrts.
 

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I just get the Motorcraft specific "Transfer Case Fluid" from the dealer... XL-12 I think it is.. It's only 2 qts so no big deal on cost compared to the cost of the TC.. :) I've changed the fluid in it at around 60k miles, so might have to start thinking about another change here soon. (just about to roll over 100k)

My old 86 Mustang GT with the 5.0 and 5 speed used ATF in the manual trans.. So there you go..

Good luck! Mitch
 

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I just get the Motorcraft specific "Transfer Case Fluid" from the dealer... XL-12 I think it is.. It's only 2 qts so no big deal on cost compared to the cost of the TC.. :) I've changed the fluid in it at around 60k miles, so might have to start thinking about another change here soon. (just about to roll over 100k)

My old 86 Mustang GT with the 5.0 and 5 speed used ATF in the manual trans.. So there you go..

Good luck! Mitch
Yep my 09 caliber with 343K km on it used Mopar ATf+4/5 and it's been changed only once it that time.
 

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Can't buy XL-12 any more. Mercon LV is the specified fluid. As far as motor oil, I would skip it. There are a lot of additives to deal with combustion in motor oil (dispersants, anti-oxidants, etc) that serve no purpose in a transmission or transfer case. Will it work? Sure. Is it better than ATF or specific fluids? No. I think a couple of quarts of redline ATF D6 would work well. I used redline ATF D4, but I'm a rebel.:rolleyes:
 
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Just drained and refilled mine in my 18 with Valvoline XL-12 compatible transfer case fluid. Cheap and simple job and I found plenty of the fluid locally.

Matt
 

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They changed it to LV like trans now. It does not matter what fluid you have in your tranasfer case, itll be ok.

As far as motor oil, why would you do this unless in a bind? If in a bind and you lost fluid, you probably cracked it and it wont matter anyways.
 
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