Hi everyone, I picked up a new 2020 2500 Bighorn this week and after 500 miles I thought I would check the axle fluid levels. In the past I normally run them about a half inch under the fill hole or sometimes barely under and never had an issue.
I removed the rear fill plug, stuck my index finger down the hole and couldn't touch the fluid. I got a piece of thick wire, made about a 2" bend and stuck that down the hole which just touched the fluid. I added over a half Qt 75-90 and the level now sets about a half inch under. The front also needed a little less then a half Qt.
Anyone else find low axle fluid levels or is that the proper factory fill level?
Prior to my Ram purchase I started drinking the ford koolaid (aluminum body, 10 speed trans) but got my senses together and went with Ram.
If this is a help to anyone, I changed the rear differential fluid in my 2019 2500 -11.5" limited slip the other day. It has a reusable rubber & metal gasket so you don't need to get a new one and it holds right at 4 qts.
This thread prompted me to change my fluid early. Thought I'd post my thoughts for anyone else considering....
Truck is a 2019 3500 SRW with the 11.5'' diff.
Truck has 10,000 miles with about 3,000 miles towing a light load (7,000 pounds).
Factory fluid was exactly where it should be about 1/4'' from the fill hole.
There was some metal on the magnet, though probably not enough to require the fluid to be changed.
Factory fluid looked okay, but not great.
I filled with 4 quarts of Royal Purple 75-90 with friction modifier. Overall, it cost me about $100 and two hours of time. While I think it would have been fine to just let it go, I guess I'm glad I replaced it... good peace of mind.
***On edit, I forgot to mention that the bolts for the cover came from the factory with loctite on them. Don't remember that on my previous trucks. Removing some of them, because of the angles and my little noodle arms, was a bit of a pita. I put them back in dry, hope I don't have issues down the road.
Youi know what will happen years from now on a fluid change. Owners and oil change places will fill diff till it starts coming out the fill hole, then seal it up. And everything will be fine.
My 2021 rear was 1 quart low. I bought the Mopar gear lube from Amazon. I am going to check the front this week. Been busy and the truck is just sitting.
Brand new 2021 2500 Cummins with 500 miles on it, crawled under for a look see. I could not touch the gear lube, front and back. I had some 80-90w GL5 with the limited slip stuff, about a quart and a half. That got the front and rear diff up to the 1/4 inch below the plug.
I find that very strange to be so low. And how critical is "1/4 in below the plug" anyway?
And I still got gear lube on my face and in my hair.....Nothing smells quite like it.
I believe anywhere from 1/4” to 1/2” below is what the manual specifies if I remember correctly.
I think most fill until it runs out the hole and never have an issue
I fill it to the hole on my AAM diffs. No problems yet. I also have a leaking front seal on my rear 11.5. No drops, only cake, but the fluid is lower but still higher than the line when I get to changing it yearly. So it’s a win.
Also, I heard that the “other” MFG using the same AAM diffs calls for it filled to the hole. I can’t confirm that. But it’s interesting.
exactly, and what do you suppose will happen a few years from now when the truck gets older and you take it a lube place, they will fill it till it comes out the plug hole. And everything will be fine.
After a month and 600 miles of easy driving, I decided to check my rear axle today. It had been sitting for 24 hours. The fluid was 1 and 1/4 inches below the bottom of the fill hole. Great job by my dealership. NOT. I am pissed. No wonder I would rather do my maintenance myself.
Reading through the post I saw some discrepancies in what fluid to use. The manual states different fluid for different axles. It doesn't state SRW vs DRW in my manual for my truck the proper fluid for my rear differential is the 75w140 because I have the rear 12" differential. For what ever reason I can't post a photo of the manual I'll see if I can repost with a photo showing what I'm reading specifically.
I just checked the manual in my 2021 3500 SRW and it calls for 75W-85 for 12" SRW. It specifies duals take 75W-140. I added .75 qt. 75W-90 Amsoil Severe Gear, it was a little low
The 19 OM recommends 75W-140 gear oil for 12.0 gears. We could assume they mean all 12.0 axles but that would be incorrect. It's supposed to read the same as is depicted in the @dslbrnr post. They (FCA) fixed the error in the 2020 OM. Go to a dealer service dept and ask them to pull up their Vehicle Quick Reference data for your VIN. That data will specify 75W-85 for the 12.0 SRW axle and 75W-140 for the 12.0 DRW axle.
Thanks for everyone's help in getting the clarification on what fluid to run for my 3500 SRW HO. I picked up Valvoline 75W-90 Full Synthetic gear oil with the limited slip additive and GL-5 rating. The rear axle at 47k miles didn't look that bad it was .5qts low. The rear differential took 4.5qts the front differential looked like brand new however it was 1.5qts low. It ended up taking 2.5qts to fill up. All together the service takes 7qts to do both front and rear. The first 20 miles or so the transmission shifting was off. I drove another 80 miles at highway speeds running errands with some stop and go traffic and then up to sustained speeds of 80mph + and everything smoothed out. I checked the differential external temperatures after the 80 mile trip with my infrared thermometer the rear cover was 165° and the front was 90° considering it was a 103° I thought those temperatures were just fine. I'm going to do the services from now on every 50k unless I'm towing a lot. I think the front could easily go double but I'll still change it for peace of mind.
This was the first time I ever used the pouches of gear oil instead of the normal bottles and holy crap is that stuff way easier to use and put into your differential. I didn't need a pump I was able to easily squeeze it in the fill hole!
Thanks for everyone's help in getting the clarification on what fluid to run for my 3500 SRW HO. I picked up Valvoline 75W-90 Full Synthetic gear oil with the limited slip additive and GL-5 rating. The rear axle at 47k miles didn't look that bad it was .5qts low. The rear differential took 4.5qts the front differential looked like brand new however it was 1.5qts low. It ended up taking 2.5qts to fill up. All together the service takes 7qts to do both front and rear. The first 20 miles or so the transmission shifting was off. I drove another 80 miles at highway speeds running errands with some stop and go traffic and then up to sustained speeds of 80mph + and everything smoothed out. I checked the differential external temperatures after the 80 mile trip with my infrared thermometer the rear cover was 165° and the front was 90° considering it was a 103° I thought those temperatures were just fine. I'm going to do the services from now on every 50k unless I'm towing a lot. I think the front could easily go double but I'll still change it for peace of mind.
This was the first time I ever used the pouches of gear oil instead of the normal bottles and holy crap is that stuff way easier to use and put into your differential. I didn't need a pump I was able to easily squeeze it in the fill hole!
I figured I would make this it's own thread for visibility if something ever happened to the link below. I probably made my favorite tool to date. Also, it will entice me to change my thicker fluids at shorter intervals. It can be used for any other fluid too as long as you clean it prior to...
I took mine into the dealership at 700 miles. They reported all levels, from engine, trans to transfer and differential were where they needed to be. I then brought it home and double checked the diff, which was at 1/2" below plug. I'm ok with that since towing pressurizes and raises heat level for expansion.
Got my new 2022 last week. Checked the diffs yesterday and both were ok.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Cummins Diesel Forum
8.8M posts
379.2K members
Since 2005
A forum community dedicated to all things Cummins Diesel! Originally founded for owners and enthusiasts of Cummins powered Dodge pickups, the Cummins Forum has expanded to include ALL Cummins Engine applications! Come join the discussion about reviews, drivetrain swaps, turbos, modifications, classifieds, builds, troubleshooting, maintenance, and more!