Differential and Transfer Case Fluid Change- My Observations

Definitely don’t want to run 75w90 in the rear diff. It takes a beating and needs the cushion. If you’re pressed for time get some Valvoline 75w140 from Autozone. Comes in the same squeeze bags too.
 
That guy at the $tealership doesn't know what he's talking about, hate to say. We do not have LSDs, we have a locker. No additive required.

I don't believe it will hurt anything being in there, but it is definitely not required and provides no benefits.
I don’t disagree with you. I had a 2019 ram 1500 limited before I sold it and got my TRX. That 2019 required the LSD additive. Whatever, $21 cheap insurance if I ever have to show Proof of proper maintenance(if that would even be acceptable). I’m at 30k miles right now. I perform this maintenance again at 60k miles or maybe 45k pending how much I beat up this truck. Hunting season is around the corner and I am planning I saving my miles for traveling to Az for quail or Utah for chukar/pheasant. I used to use my truck as a daily but I was able to get my 2002 Mazda b2300 back and use that as a daily! (Hell yea!). Anyway… will definitely look at amsoil and ravenol for my next go around! Also credit to the first post for recommending the squeeze bags. I just realized that was recommended before I posted my experience.
 
Amsoil redtop works fp
I may switch the amsoil for the front and rear. I see folks using ravenol on here but I’ve never had any experience with it. I’ve also heard the red bag amsoil for the transfer case but idk. I’ll research it in about 30k miles from now. Thanks
Yes you can ise red top amsoil for Tcase.
Changed mine at 501 miles no issues at all.
Zero slip.
I also did axles along with transmission which is blue top.
Super smooth shifts and zero slip.
 
Hudrolic tractor oil is a type of atf without the red dye. Usually a 10-20w
The lower oil has a better chance of not foaming at high rate of flow speed.

The older vehicles say a 205 t case from the 70's used 75w gear oil because they where a direct gear drive tcase.
Tractor hydraulic fluid comes in many different viscosities, it's AW followed by a number. AW 32, for example, is equivalent to 10 weight motor oil.

Was a bit surprised when finding out the the NP205 in my '91 Chevy called for ATF. Promptly drained it and put gear oil in it.
 
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Does this look right? For front diff spec calls for 75w-85 I think, but from what I can gather in this thread, most are using 75w-90
 
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Does this look right? For front diff spec calls for 75w-85 I think, but from what I can gather in this thread, most are using 75w-90


If you really want you can run the 75w 85 they just made it for these newer trucks I picked some up but ran 75w 90 in my last trx no issue
just showing you they make it now
 

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If you really want you can run the 75w 85 they just made it for these newer trucks I picked some up but ran 75w 90 in my last trx no issue
just showing you they make it now
Yeah I saw that, I wasn't sure what the difference (if any) would be.
 
75w85 only exists to squeeze out an extra teeny tiny bit of fuel economy. Kind of ridiculous when you look at the TRX, but they just carried the spec over from the regular 1500s. I have 75w90 up there currently. Little extra viscosity never hurt anything.
 
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