20k Service Interval

The 20k service interval is a decent sized to-do list for the Ram 2500. For the Hemi, it includes:

  • Oil change
  • Grease front driveshaft
  • Front and rear differential fluid change
  • Cabin air filter change
  • Bonus
    • Fuel treatment
    • Front diff guard

The oil change is the same as usual. That said, this round I changed from Pennzoil Ultra Platinum to the only other approved motor oil, AMSOIL. I’m going to go in depth about this in another post… But the short version is that following the 8k intervals suggested by FCA, the oil viscosity is breaking down. Some might argue I should follow the severe service intervals. That said, at $10 a quart and Pennzoil’s flagship product, I expect better. A lot better.

For example, AMSOIL’s Signature line has a standard interval is 25,000 (!) miles. Severe is reduced to 15,000… double what the standard is for Pennzoil. Again, I’ll cover this in depth with Blackstone reports in the future.

I’ve also started using AMSOIL PI at my oil changes in addition to greasing the front drive shaft. My first tank did yield an increase in average fuel economy that was in line with what they claim. At only 20k miles… it’s something that will remain in the routine. I’d imagine vehicles with more miles will yield even more impressive results.

I’ve long planned to install differential skids or covers at the first change interval. I settled on front only and went with the Carli. It says on their website that Power Wagons may need modification to fit. On my 2018, that was not the case.

Both the front AAM 9.25 and rear AAM 11.5 had reusable metal and rubber gaskets. God was I glad to see that! So much better than the constant nightmares of RTV. No leaks!

I replaced the fluid with AMSOIL Severe Gear 75W-90. No additive required for the LSD in the rear. I put a little over two quarts in the front and about four in the rear. I’d buy seven to be safe. The AMSOIL Easy-Packs are money! No more pumps!

I’ve seen a few people ask about the brake line attachments on the rear. They use a bolt with threads on either side. You’ll need a deep socket or combo wrench and patience to get them off. Once the top bracket is off, it can be pushed above and back behind the lip (and out of the way). The passenger side is just a push nut that can be pried off with a screwdriver and replaced by pushing back on afterward.

I’ve also heard competing comments on torque values for the diff cover. My experience from every manufacturer is that the values they provide are high enough to shear bolts off in the diff. And having done that more than once, I tend to go low. I used 20 ft-lbs front and rear without any sheared bolts or leaks.

The cabin filter is your standard, tool-less job. With a filter in hand, remove the stop string from the right side of the lower glove compartment. Then squeeze the glove box together and spill all our shit onto the floor – including to door. There are little tabs on the cabin filter cover on each side. Squeeze those inward and remove the door. Replace the filter paying attention to air flow. Then reassemble the glove box – taking time to clean out your glove box now that its entire contents are on the floorboard.