2016 CTD 2500 REAR DIFFERENTIAL QUESTION

SweetLou wrote:

Cummins12V98 wrote:

SweetLou wrote:
I just replaced my rear diff oil today in my CTD 3500. It's 11.5 rear end I used Amsoil 75w-90. I bought 4 bags or qts. My fill mark is stamped on the cover plate about 3/4 inch down. I bent a tool to that mark and filled it up. It only took exactly 3 qts or bags. So did I under fill according to some here on this post?

What does AMZ/OIL or your manual list the capacity to be?

8 pints, but that would go over the fill mark stamped on the outside cover.

If you put three in and it's 3/4" below fill hole most of another quart will fit. Are you on dead level ground doing the fill?

Level ground, fill til it starts running out insert plug. It will take just under 4 quarts or - 8 pints. I always fill to hole, never an issue.

Cummins12V98 wrote:

SweetLou wrote:
I just replaced my rear diff oil today in my CTD 3500. It's 11.5 rear end I used Amsoil 75w-90. I bought 4 bags or qts. My fill mark is stamped on the cover plate about 3/4 inch down. I bent a tool to that mark and filled it up. It only took exactly 3 qts or bags. So did I under fill according to some here on this post?

What does AMZ/OIL or your manual list the capacity to be?

8 pints, but that would go over the fill mark stamped on the outside cover.

SweetLou wrote:
I just replaced my rear diff oil today in my CTD 3500. It's 11.5 rear end I used Amsoil 75w-90. I bought 4 bags or qts. My fill mark is stamped on the cover plate about 3/4 inch down. I bent a tool to that mark and filled it up. It only took exactly 3 qts or bags. So did I under fill according to some here on this post?

What does AMZ/OIL or your manual list the capacity to be?

I just replaced my rear diff oil today in my CTD 3500. It's 11.5 rear end I used Amsoil 75w-90. I bought 4 bags or qts. My fill mark is stamped on the cover plate about 3/4 inch down. I bent a tool to that mark and filled it up. It only took exactly 3 qts or bags. So did I under fill according to some here on this post?

SweetLou wrote:

Cummins12V98 wrote:

Ron3rd wrote:

Cummins12V98 wrote:
Highly advise dumping the OE fluid and run AMZ/OIL SevereGear 75–90.

Good info. Do you know the capacity? I've seen conflicting info online

I just did a 3500 11.5” rear axle and it took a hair under 4 quarts.

How much goes into the front transfer case for 4x4?

Transfer case or front axle?
Front axle is about 2.5qts.
T case is about 2 qts but takes ATF not gear lube. All the capacities are in your owners manual for reference.

rhagfo wrote:

Grit dog wrote:
Yup get 4qts. You'll have a little left over.
Book says fill to fill line, 1/2" down from hole or something like that. I wouldn't worry if you get extra in it.
It's to keep oil from filling the axle tubes part way, but the bottom of the hole looks to be right at bottom of axle tube. Never been an issue filling to the hole on any vehicle yet.

Well you want it in the axle tubes, as all Full Floating axles I have had that is what lubes the wheel bearings. you don't want the tubes too ful, just to get lube to the wheel bearings.

Correct

After watching several Banks diff cover videos, I wouldn't get any flat back diff cover.
https://www.youtube.com/watch?v=0PMvVcsU3PE

You may also consider a Mag-Hytec differential cover. These offer more capacity ( lowers oil temps a bit), a sight glass to easily monitor your fluid level, a magnet in the drain plug to keep metal particles from traveling around in the oil, also has a threaded port where you can put in a temperature sensor/ sending unit so you can monitor your rear differential temperatures. This is a helpful addition to your tow vehicle..... especially if, you do a lot of heavy towing in mountainous regions!

Cummins12V98 wrote:

Ron3rd wrote:

Cummins12V98 wrote:
Highly advise dumping the OE fluid and run AMZ/OIL SevereGear 75–90.

Good info. Do you know the capacity? I've seen conflicting info online

I just did a 3500 11.5” rear axle and it took a hair under 4 quarts.

How much goes into the front transfer case for 4x4?

My '03 2500 Dodge/Cummins has the 11.5" AAM rear axle with 327000 miles and have never packed the axle bearings with wheel bearing grease....just good ol' 80w-140 Redline synthetic.
Front bearing got the grease.

Dodge screwed the pooch on the 1st year AAM 11.5" fluid levels. Mine as some others came with fluids 3/4" below the hole per AAM so says Dodge. At around 3500 miles the AAM started a whine. So I checked the fluid and found it was indeed 3/4" low so having contacted AAM I filled it to the bottom of the hole (almost one more qt). The whine didn't get any worse but wasn't what a new truck should be doing. Went to the dealer and they say a new axle housing and all.....but STAR says no.
At about 25k miles of hard pulling GN trailers the whine went away.