PSA CHECK YOUR TRANSFER CASE

[Mouse]

I checked my transfer case today and it was low. It took exactly 17oz to top off. I use a giant syringe because I wanted to pull a sample from the T-case prior to adding more fluid. It worked well to pull the sample inspect the oil and pump back into the T-case with out contamination. Then measure the amount of oil it took to top off the oil level. Plan to use this method to pull samples from the front and rear differentials as well.

This was the sample pulled from the T-case

 

[Viking Jeeper]

I'm a bit embarrassed to admit I have known about this thread for some time now but just today checked. Transfer case and rear diff were full, front took about 2-3 oz.

 

[Mouse]

Checked my front differential today and it was low enough that I couldn’t touch the oil with my pinky. So I cracked the cover and what drained out still looked clean just low. I would estimate it was only half full. Refilled with royal purple 75w90. Checked the back and it was about a 1/16 of an inch low but I dumped it anyway. It came out black, worse than my JK that hadn’t been changed in 12 years. Refilled that with the same 75w90 RP. Did my JK as well and even after driving in water halfway up my doors several times and being the original oil since 2010 it still looked better than the 392 with 3500 miles at 8 months old.

a look at the rear oil, it had a good amount of metal flake in it, no chunks though and the magnet was mostly clean. may do another oil change after another 3000 miles.

 

[Mooserat]

My Jeep 392 Tcase was down about a pint ATF +4 and I changed my diff fluid for my front and rear 75w-85 synthetic. They were low too. 7,500 miles. My buddies 392 was low on the Tcase and the front-rear diffs. My diff fluid was clean, next to no metal. I figured it was worth the change based on the fact it was low from the dealer - factory and there has been a problem with debris getting into the e-lockers in the JL Rubicons.

 

[SkeetShooter69]

Do yourself a favor and check the level of fluid in your transfer case. I was poking around under the 392 today and decided to pull the fill plug on the transfer case…. Low and behold the case was 1/2 quart low. I had the same issue with my TRX and if you pay attention on the TRX forum it’s a known issue. 392 takes Mopar ATF 4 which you can grab at your dealer or on Amazon. I’ll probably be checking the level on my diffs next weekend. Those were also low on my TRX.

Do yourself a favor and check the level of fluid in your transfer case. I was poking around under the 392 today and decided to pull the fill plug on the transfer case…. Low and behold the case was 1/2 quart low. I had the same issue with my TRX and if you pay attention on the TRX forum it’s a known issue. 392 takes Mopar ATF 4 which you can grab at your dealer or on Amazon. I’ll probably be checking the level on my diffs next weekend. Those were also low on my TRX.

I’m new here and wanted to thank you for this. I have a new 2023 Rubicon 392 with 670 miles on it. Did some light (dirt trails) in Gorman last weekend. After putting the Jeep in 4lo, my 4wd service light came on. Dropped it at the dealership yesterday and am getting a new transfer case installed tomorrow. I called them back after reading your post and asked them if they would check the diff levels. They’re doing that now as well.

 

[Mouse]

I’m new here and wanted to thank you for this. I have a new 2023 Rubicon 392 with 670 miles on it. Did some light (dirt trails) in Gorman last weekend. After putting the Jeep in 4lo, my 4wd service light came on. Dropped it at the dealership yesterday and am getting a new transfer case installed tomorrow. I called them back after reading your post and asked them if they would check the diff levels. They’re doing that now as well.

If you haven’t done it already, check your fuse box and make sure every fuse and relay are firmly and completely seated.

 

[SkeetShooter69]

If you haven’t done it already, check your fuse box and make sure every fuse and relay are firmly and completely seated.

Thanks, I read that tip too. I plan to do that juuust as soon as my brand new jeep gets out of the shop.

 

[Viking Jeeper]

I’m new here and wanted to thank you for this. I have a new 2023 Rubicon 392 with 670 miles on it. Did some light (dirt trails) in Gorman last weekend. After putting the Jeep in 4lo, my 4wd service light came on. Dropped it at the dealership yesterday and am getting a new transfer case installed tomorrow. I called them back after reading your post and asked them if they would check the diff levels. They’re doing that now as well.

670 miles and new transfer case! You dont say specifically but it sounds like your fluid level was low. Is that correct?

 

[SkeetShooter69]

670 miles and new transfer case! You dont say specifically but it sounds like your fluid level was low. Is that correct?

“Sometimes these Jeeps sit on the lot for a while…” is the non-answer response I received. My assumption is that it wasn’t filled properly.

 

[thexr6]

Okay I just watched this video on changing transfer case fluid:

I think it's a good idea of having the ATF+4 automatic transmission fluid by side just in case it's low. And apply thread sealant to the fill plug threads. I didn't use any thread sealant on the oil pan drain plug though.

Good video. Finally a youtuber i can tolerate.

 

[Hoghead]

Mine 23 XR was alittle more than a quarter of a quart low. Thanks.

 

[At Risk Ute]

Changed my gear oil today and checked the fluid on my replacement transfer case. Was completely full!

 

[7.62x392]

I’m approaching 15K miles and am going to cycle the factory transfer case fluid soon. For those that have refilled it, what fluid did you use?

 

[Fast-n-Furious]

I’m approaching 15K miles and am going to cycle the factory transfer case fluid soon. For those that have refilled it, what fluid did you use?

I used this when I topped off. Can't speak how much you'll need for a complete refill.

 

[redbeard719]

^^
That is the same fluid I used to top off my factory T-Case fill as well. I had planned to use the same when doing fluid changes, but I’ve got a ways to go before I need to do that.

It’s cheap enough though at ~$13qt, I may do it at each engine oil change interval. Certainly wouldn’t hurt.

Now, differential fluid…. That is one I need to figure out sooner than later since I have new covers on the way and would like to pot the locker sensors ASAP.

 

[7.62x392]

^^
That is the same fluid I used to top off my factory T-Case fill as well. I had planned to use the same when doing fluid changes, but I’ve got a ways to go before I need to do that.

It’s cheap enough though at ~$13qt, I may do it at each engine oil change interval. Certainly wouldn’t hurt.

Now, differential fluid…. That is one I need to figure out sooner than later since I have new covers on the way and would like to pot the locker sensors ASAP.

I used Royal Purple when I changed the diff fluid.

 

[redbeard719]

I used Royal Purple when I changed the diff fluid.

Dare I ask… what weight did you use?!

 

[7.62x392]

Dare I ask… what weight did you use?!

Haha I know there’s been some strong opinions on this. I used 75W90 for the front and 75W140 for the rear and so far so good.

 

[stumblinhorse]

Haha I know there’s been some strong opinions on this. I used 75W90 for the front and 75W140 for the rear and so far so good.

Lol, def strong opinions that 75w140 is best for your diff. 75w90 is best for your warranty and cafe standards

 

[EquipAndExplore]

I'm a bit embarrassed to admit I have known about this thread for some time now but just today checked. Transfer case and rear diff were full, front took about 2-3 oz.

I checked my levels (all 3) right after I brought her home from Granger (~700 miles). All 3 were full and over flowed after 1 or 2 pumps. Not sure if Granger were checking them as part of their PDI or if the Jeep crew were on their A game in the day that my 392 was built.