ram 2500 and 3500

"Up through MY 2019 3.42 gears were the only ones available in SRW diesels"

You should have said 2018.

MY 2019 all Diesel SRW 2500/3500's have 3.73's that's it!

MY 2019 Diesel DRW's have the choice of 3.73 and 4.10 that's it!

I believe brakes are the same, as mentioned coils vs leafs on the rear, the rear air leveling suspension can be had on both but are different systems likely due to the coil vs leaf setup. And also as mentioned previously the 3500 you can get the Aisin trans. When I bought my 17 3500 SRW you had no choice in axle ratio only the DRW's had that option so same as the 2500 but that may or may not have changed since then. The payload difference, gvwr and gcwr whether real or just on paper not sure but since they do have different suspensions unlike earlier years it may very well be different. I know that when I bought my 17 the difference between the longbed, cc, 2500 and the longbed, cc, 3500 srw was literally about $400. And for that amount I went with the 3500 especially since the 2500 payload numbers were around 2000lbs less and with my use I was close to the max on the 2500 so for $400 went tothe 3500 and peace of mind.

Road Phantom wrote:
What is the actual difference between the Ram 2500 and 3500 single wheel pickups besides leaf springs and coil. Are the bearings and brakes the same if both have 18 inch rims?

Other than the coils(2500) vs leaf spring(or rear air)(3500), the availability of the Aisin optional transmission in the 3500 really tips the scale in favor of the 3500. Up through MY 2019 3.42 gears were the only ones available in SRW diesels, so the low first and second gear in the Aisin makes for much better towing. MY 2020 is said to be getting 3.73 gears in the SRW diesels.

So 3500/Aisin and your choice of leaf springs or rear air is the way to go if you are going to tow heavy.

Tire options are 18" or 20" in higher trim levels, and I think the Laramie 18" wheels are the best looking of the lot. Click "our rig" in my sig line. I lower the rears to 42 psi when not towing or carrying a load.

We towed a 16K 5th wheel with our 2015 3500 4x4, CC, SB, SRW/Cummins/Aisin at a combined weight of 24,500 and it worked well. 5th wheel trailer is now parked year round and we tow a same bumper pull TT back and forth to Az.

BTW we love our 3.42 gears. 80 MPH at 1750 RPM and 19 MPG is great.

RAM did not have to give the 2500 a max RGAWR of 6500 vs the 3500 7000, so their engineers must of felt that the coils were not up to the 7000 rating. If you are one that is concerned about GVWR, then it is 10K for the 2500 SB or LB and 11,700 for the SB 3500 and 12,300 the LB 3500.

Resale of a 3500 should bring more than the difference out the door when new.

In the old days (not that long ago really) for most of the manufacturers, the difference between a 3/4 ton and a SRW 1 ton was the spring pack.

Dodge did make a pretty big change when they went with coil springs in the 3/4 ton. That's a fundamental change in suspension design...not sure exactly what else changed but just swapping out springs to make a fake 1 ton is likely not as simple.

Wheel/tire size isn't indicative of axle/bearing sizes.
All 2500/3500 srw Dodge/Rams have the same 11.5" AAM rear axle which AAM rates in the 10700 lb range. The 2500 is limited by its 6000-6500 rawr which is the lessor of the wheels/tires/rear spring pack ratings. Same for the front axle that comes in various weight ratings.

Before the 2500 rear coils showed up the only difference in the 3500 srw was the rear spring pack.
The Cummins option gave the truck higher front spring pack ratings and heavier front axles vs the gas version on some 2wd cab configurations.

Brakes ??
According to Dodge/Ram techs on TDR or DTR or Cummins/other forums they can carry the same brakes; such as a crew cab Cummins option 4wd.

See IB516 posts for his experience with the 2500 coils and a 12k-13k 5th wheel trailer

Lots of reading online if you do a search. Here’s a start.

What model year?

All I know for sure is the "payload's" of each makes a Big difference even without the dual rear wheels. A friend who wanted a 5th wheel didn't realize the Payload difference after he went with a 2500...he now owns a heavy Trailer rather than a 5th wheel.