Differential and Transfer Case Fluid Change- My Observations

[TyRex]

Thanks. I have AMSOIL and Mopar fluids inbound going to attempt these fluid changes myself this weekend.

If you are low in miles, buy the sealant just in case. Once you remove (only t-case plugs and rear diff fill plug) the plugs, check the thread sealant and probably it will be good to reuse, so do not re-apply. If you decide to apply the Loctite you bought, then remove the old thread sealant, brush it to clean it well and then apply the new sealant. I did it when I removed them to let them dry a little more before. Try to clean all the oil around the holes before putting back the plugs.

Clean all the metals in the rear-diff plugs, you will be surprised! If you buy 3 Qts of read diff fluid, I would use 0.5 Qts to apply letting open the drain hole so you can get more dirt out of the diff. I did the same for the front diff and of course, the t-case (like 7-8 did that ). T-case is 1.9 - 2 Qts, only if you vacuum the remaining fluid on it, you will get the 2.5 Qts mentioned in Tyler's video.

Do you have a way to lift the truck? Do it! Trust me.

 

[BuckeyeROC]

Question about the rear axle fluid. I see everyone buying the SAE 75W-140, but the owner's manual states for a 3.55 rear to use SAE 75W-90. Thoughts?

 

[Bigdawg]

If you are low in miles, buy the sealant just in case. Once you remove (only t-case plugs and rear diff fill plug) the plugs, check the thread sealant and probably it will be good to reuse, so do not re-apply. If you decide to apply the Loctite you bought, then remove the old thread sealant, brush it to clean it well and then apply the new sealant. I did it when I removed them to let them dry a little more before. Try to clean all the oil around the holes before putting back the plugs.

Clean all the metals in the rear-diff plugs, you will be surprised! If you buy 3 Qts of read diff fluid, I would use 0.5 Qts to apply letting open the drain hole so you can get more dirt out of the diff. I did the same for the front diff and of course, the t-case (like 7-8 did that ). T-case is 1.9 - 2 Qts, only if you vacuum the remaining fluid on it, you will get the 2.5 Qts mentioned in Tyler's video.

Do you have a way to lift the truck? Do it! Trust me.

Thanks for the advice and direction. Will do.

 

[TyRex]

Question about the rear axle fluid. I see everyone buying the SAE 75W-140, but the owner's manual states for a 3.55 rear to use SAE 75W-90. Thoughts?

View attachment 128947

@PotterTRX might help you with the explanation

 

[TyRex]

Question about the rear axle fluid. I see everyone buying the SAE 75W-140, but the owner's manual states for a 3.55 rear to use SAE 75W-90. Thoughts?

View attachment 128947

What owner manual is that with 486 pages?

 

[BuckeyeROC]

What owner manual is that with 486 pages?

The main 2022 RAM 1500 Owner's Manual. I looked in the TRX supplement and didn't see any recommended changes to this fluid.

 

[TyRex]

The main 2022 RAM 1500 Owner's Manual. I looked in the TRX supplement and didn't see any recommended changes to this fluid.

Probably you have your answer there?

 

[MyWifeLetMe]

Question about the rear axle fluid. I see everyone buying the SAE 75W-140, but the owner's manual states for a 3.55 rear to use SAE 75W-90. Thoughts?

View attachment 128947

75w90 is better for lower power/tq vehicles, colder climates, and gets slightly better fuel mileage because the oil is thinner at higher temp. 75w140 is better for higher power/tq vehicles, hotter climates, and protects better when towing or accelerating heavy/racing. That booklet refers to the regular 1500 truck more than ours. Being a higher horsepower truck with a lot more torque 75w140 would better protect the rear axle

 

[TyRex]

 

[TyRex]

75w90 is better for lower power/tq vehicles, colder climates, and gets slightly better fuel mileage because the oil is thinner at higher temp. 75w140 is better for higher power/tq vehicles, hotter climates, and protects better when towing or accelerating heavy/racing. That booklet refers to the regular 1500 truck more than ours. Being a higher horsepower truck with a lot more torque 75w140 would better protect the rear axle

Thank you @MyWifeLetMe, I was looking for this answer too.

 

[Bigdawg]

I wanted to say I appreciate this group of TRX owners. For without I might not try some of this stuff. While not overwhelmingly complicated I wanted to mention some of us new “wanna be” mechanics appreciate it. So a great write up and video that really helped me break through my fear barrier of tackling something like this myself. What’s the worst thing that could happen that a tow truck to the dealer couldn’t fix? I finally attempted and completed the Rear axle fluid change without issue. Fully drained and my 22 took about 2.5qts of Amsoil 75w140. Off to the front and transfer case. Thanks TRX forum.

 

[TyRex]

 

[jagarcia89]

Just tackled this myself. Used your guide as reference as well as the actual service information. One area that was interesting was your assessments of how much each took. So here are actual capacities per the service information:

Front Diff - 2.32 pints of 75w/80. I used the amsoil severe gear 75w/90 like you and it took one quart and a bit more
Rear Diff - 5.03 pints 75w/140. I used the 75/140 amsoil here as well and it took just about exactly a 2.5 qts
Transfer case -3.8 pints of Mobil Fluid LT. I differed here and went with Amsoil ATF. They put in writing it meets the specs of the 68049954AA the service info calls for so I'm trying it out. It took just about exactly the 2qts. Maybe you needed the 3 because the hard bottle prevented fully emptying the container, but otherwise there should be no reason it takes any more than 2qts.

Specified torque values:
F Diff drain/fill plugs: 26 ft/lbs
R diff plugs: 20 ft/lbs
T Case: 18 ft/lbs

I only had 1 set of ramps and wanted to stay level so I did it on the ground. Doable, but I'm a bit more sore than necessary.

I also found no extension worked best on the t case for me and just going in front of the exhaust vs using an extension to go from behind it. I was able to do this for both plugs.

 

[Rockin98]

Just tackled this myself. Used your guide as reference as well as the actual service information. One area that was interesting was your assessments of how much each took. So here are actual capacities per the service information:

Front Diff - 2.32 pints of 75w/80. I used the amsoil severe gear 75w/90 like you and it took one quart and a bit more
Rear Diff - 5.03 pints 75w/140. I used the 75/140 amsoil here as well and it took just about exactly a 2.5 qts
Transfer case -3.8 pints of Mobil Fluid LT. I differed here and went with Amsoil ATF. They put in writing it meets the specs of the 68049954AA the service info calls for so I'm trying it out. It took just about exactly the 2qts. Maybe you needed the 3 because the hard bottle prevented fully emptying the container, but otherwise there should be no reason it takes any more than 2qts.

Specified torque values:
F Diff drain/fill plugs: 26 ft/lbs
R diff plugs: 20 ft/lbs
T Case: 18 ft/lbs

I only had 1 set of ramps and wanted to stay level so I did it on the ground. Doable, but I'm a bit more sore than necessary.

I also found no extension worked best on the t case for me and just going in front of the exhaust vs using an extension to go from behind it. I was able to do this for both plugs.

Nice write up.
Hopefully you can feel thr tcase smoother already.
When I changed mine to Amsoil it made a hige difference. No more slipping

 

[FULLTHROTTLERICK]

Nice write up.
Hopefully you can feel thr tcase smoother already.
When I changed mine to Amsoil it made a hige difference. No more slipping

Curious, when did you feel slipping exactly?

 

[2026TRX]

They put in writing it meets the specs of the 68049954AA the service info calls for so I'm trying it out.

But the TRX calls for 68049954AC, is AA for 2009-2020 vehicles? Outside of the TRX years. I want to do my fluids soon and get the new stuff out.

 

[DirtMcGirt8732]

Nice write up.
Hopefully you can feel thr tcase smoother already.
When I changed mine to Amsoil it made a hige difference. No more slipping

Changed my TC fluid today with the Ravenol BorgWarner TC fluid and noticed this too. Mine would slip sometimes on initial acceleration, mostly after a turn. It only seemed to happen in Auto though. First drive after changing the fluid and it’s completely gone.

 

[FULLTHROTTLERICK]

We changed our TC fluid to the Redline D4 Synthetic ATF per @OnTheReel 's rec. So far everything is buttery smooth in the driveline. Redline in the front axle, TC and rear axle.

 

[Rockin98]

Curious, when did you feel slipping exactly?

Under hard launch ot would slip. I felt chatter a few times also. After changing everything to amsoil its super smooth. No more chatter or slipping.just bites.

 

[Engine45]

We changed our TC fluid to the Redline D4 Synthetic ATF per @OnTheReel 's rec. So far everything is buttery smooth in the driveline. Redline in the front axle, TC and rear axle.

Would there be any problem with the redline D6 ATF fluid in the t case
Or is the D4 closer to spec ? Any amsoil fluid close to spec to use ? Also the transmission fluid any recommended amsoil or redline ATF ?
Can the gurus chime in.