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2020 Transfer Case Under-filled From Factory

Caveman

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Changed my transfer case ATF today. I bought the truck used fairly early in its life, and I'm pretty sure the transfer case ATF hasn't been changed before, both from the service records and from the factory-looking thread sealant on the fill and drain plugs. I drained about 1.5 quarts of fluid and refilled with very close to 2 quarts. No leakage anywhere around the transfer case. Not worried about the transfer case, as that fluid level isn't critical, but it does make me wonder about what else might have been under-filled from the factory, most notably the automatic transmission. Anyone have similar experience with under-filled fluids from the factory?
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bleda2002

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Most likely your coolant, both my jt and the wife's JL were under filled
 
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ShadowsPapa

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Don't fret over or get hung up on one instance like that.......
Both of mine have had all fluids up to snuff just fine, nothing was low until I drove them a while.
 

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Same here. Coolant level was below minimum line.
That's very likely to happen. It's been a thing since at least the 1970s.
We used to flush systems, drain and refill, and so on, or after engine rebuilds, we'd fill - then, you drove it....... and you made sure the customer knew that it may need topped off after a few drives. There's often air that gets caught or trapped in the recesses of the castings, or high spots in the cooling system. It was a real issue with the 258 and more in the 4.0 because of that very thing. In fact, the correct thermostat for those has a small hole in the flange that must be put up at 12:00 to help allow the air to be purged.
I found that mine showed full until a few weeks later, then I topped it off and it's pretty much stayed there since. That tells me it was due to air in the system, and multiple drives, heating and cooling the coolant AND air in the system finally flushed it out. Both of my JTs read at the correct level (in the middle) until I'd done a bunch of short drives, shopping trips and so on that allowed for a lot of expansion and contraction of the air within the system.
When I do engine builds - that's always the bit you need to check after some drives. It's just a thing.
 

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What after market coolant is compatible with the factory stuff?
 

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What after market coolant is compatible with the factory stuff?
Check the BOOK. It gives the spec (MOPAR spec number) and the type.
OAT - don't use anything else. You could end up with a mess.

OAT - and don't get confused by color. It used to be there were color standards but that isn't always the case today. It MAY be pink or orange or even some other color, depending on the brand.

Best bet is to READ the jug - make sure it says that it's OAT coolant.
 
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Caveman

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Just got out to check the coolant, and damned if the overflow tank isn't dry. What's surprising is that up until now, the truck always been dealer serviced. I guess the "inspection" included with each service wasn't very thorough.
 

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Just got out to check the coolant, and damned if the overflow tank isn't dry. What's surprising is that up until now, the truck always been dealer serviced. I guess the "inspection" included with each service wasn't very thorough.
Yeah, they'll give you the washer fluid because it's so bloody cheap, but the coolant and EHPS fluids are expensive so we pretty much should keep track of those ourselves.
I did note that they added to my wife's Grand Cherokee fluids a couple of times before she got the JLU, but too often they don't catch - or are too cheap to top off - those other fluids.
Odd that it would be dry - so maybe best to keep a close eye on it. Even low, it shouldn't require THAT much coolant, so something to watch. I can go a year or more and not find mine at the low mark.
 

nanook12

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Check the BOOK. It gives the spec (MOPAR spec number) and the type.
OAT - don't use anything else. You could end up with a mess.

OAT - and don't get confused by color. It used to be there were color standards but that isn't always the case today. It MAY be pink or orange or even some other color, depending on the brand.

Best bet is to READ the jug - make sure it says that it's OAT coolant.
wow you are a lot of help! How would this site get by without you.
 

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Caveman

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Odd that it would be dry - so maybe best to keep a close eye on it. Even low, it shouldn't require THAT much coolant, so something to watch. I can go a year or more and not find mine at the low mark.
I will definitely keep an eye on it! But perhaps not that odd given that it rolled off the line over 5 years and 60K ago...
 

ShadowsPapa

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I will definitely keep an eye on it! But perhaps not that odd given that it rolled off the line over 5 years and 60K ago...
LOL - I missed the bit on your profile there, a 2020 and with some miles.
 

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It is pretty common on new vehicles to have fluid levels be a "minimum fill" and not full service fill. One of those things that pennies add up to millions saved on production cost.

Being on my third Gladiator, all three had both diffs underfilled by at least 8oz with transfer case maybe 4oz-6oz. All the transmissions though seemed to be fully serviced when I did fluid and filter changes on them.

Recently did a full service workup on my wife's Bronco Sport and it was the same way of underfilled except the service spec fluid quantities on it are even way less and more critical.
 

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The diffs were regularly under filled, I actually think that might have been a part of the problem leading to the axle shaft leaks early in JT years. When I changed the gear oil in mine I doubt that there was 3 qts between them.
 

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The diffs were regularly under filled, I actually think that might have been a part of the problem leading to the axle shaft leaks early in JT years.
Why mostly one year, and why the right side?
Why would underfilling cause a leak, but not bearing issues?
2020 model year didn't have the issue, and the later years don't seem to have it - it's pretty much 2021, maybe early '22.
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