Gear oil questions, Aisin too

[DFrank]

I'm in a '19 Ram 3500, Aisin, HO, and I was just looking over my owners manual for fluid changes.

The line that reads " inspect the front and rear axle surfaces", only says to change the fluid if used for police, taxi, etc, but no mention of mileage interval if its used as an interceptor or a grocery getter. Literally the whole box is blank of the Xs marked at intervals for various other categories.

I've had it in my head that it was due at 30K, but nowhere does it say how often.

I just crossed 30K miles.

What brand oils/ weights are folks using? I've just learned about the little squeezable packets of amsoil gear lube, that seem handy, but I am just seeing these in 75W90, and Ram says 75W85 front, and 75-w140 for the rear.

The manual seems very poorly laid out, and I don't see anywhere that lists the fluid quantities for anything.

And for the transmission, are you dropping the pan, or just draining it? I read to catch what you drain and add that same amount. How much of this should I buy, and what flavor of this fluid do you guys like?

Thanks,
Dave

 

[nukegm]

comrade - a lot of members here say get the factory oil out asap. i did mine at 20k. replaced with amsoil severe gear. nothing of interest in the old fluid, just dark. did the rear again at 40k. on the front i just did a " suck out " and refill with a hand pump. fluid looked new. you can internet order the amsoil these days. way cheaper than the factory fluid. 2018 2500 g56 currently at 54,000 miles. cheers!

 

[AH64ID]

This is from page 501 of the 2019 manual. The “X” is every 20K.

Inspect the front and rear axle surfaces. If gear oil leakage is suspected, check the fluid level. If using your vehicle for police, taxi, fleet, off-road or frequent trailer towing, change axle fluid.

The OE gear lube is “lifetime” if you don’t tow and 20K miles if you do tow. Based on my experience the OEM gear lube is a 15K mile fluid towing or not, but maybe the 75w-140 in the 12.0 DRW is better. It was the nastiest gear lube I’d ever changed at 15K miles.

I use Amsoil Severe Gear in mine. The ez fill packs are awesome. I run 75w-90 in my front/rear but I don’t have the 12.0 or a DRW. I ran that fluid for 50K in my 05, and 100K on my 03 4Runner. In both cases the fluid came out better than the factory fill at 15K. I’m undecided on service interval with the 18. I tow, but not sure what “frequent” means to Ram. Should be 51% or more, but???

As for the Aisin the 30K is a drain and fill. It takes about 7.2 quarts. No need to measure what you took out.. we don’t do that with any other fluid. Use the dipstick, that’s what it’s there for. I’m using Amsoil ATF since it has ASRC printed on the bottle. It’s been great so far. Same fluid I use in my 03 4Runner with an Aisin that calls for the same spec fluid.. 208K trouble free miles on that trans.

 

[DFrank]

Thanks John. I ran the amsoil severe gear in my 03, and when I drained it after 50k, I'd have put it right back in, had I caught it in a clean bucket.

I will do their 75-90 in the front, and the 75-140 in the rear.

I didn't specify, but mine is SRW. My towing is light and infrequent, at least compared to most.

I assume the reason somone suggested to measure what came out of the transmission is that you're getting all of it and you dont know how much was left behind.

 

[AH64ID]

As a SRW I believe you are supposed to run 75w-85 front and rear, so 75w-90 SVG should do.

EDIT: It seems the 2019 manual calls for 75w-140 in all 12.0’s, while the 20+ manual only calls for 75w-140 in the 12.0 DRW axle.

I’d guess the 20+ also applies to 19, but your call for warranty.