Ram 3500 High Output Cummins Build on 37's

Explorerinil

Observer
I was originally worried about this as well until I actually got the truck and started driving around with the 3.73's. I think we should be ok considering Ram used to run 3.42 gears and the Aisin has such low 1st and 2nd gears. That being said, I do not tow like you do however.

You may be waiting a long time before there are aftermarket gears for this new axle. Have you looked into using the 4.10's out of a dually? That way it'd be OEM as well.
You can buy OEM 4:10 gears, nitro has (or at least had) OEM gear sets. On my 16 ram cummins HO I ran 37x13:50 and 4:30 gears which was perfect… you may find that you will want at least 4:10’s.
 

GPurcell01

Active member
You haven't mentioned that Ram returned to the Bosch CP3 reliable injection pump. Both Ford and Ram have had issues with the CP4.

This is why I went for new instead of a used 2019 or 2020. The price was about the same with the market right now anyways lol
 

GPurcell01

Active member
You can buy OEM 4:10 gears, nitro has (or at least had) OEM gear sets. On my 16 ram cummins HO I ran 37x13:50 and 4:30 gears which was perfect… you may find that you will want at least 4:10’s.

Yes! This was another benefit of getting the HO. The axle is the same on these newer trucks for both the dually and SRW. Hemi or standard output trucks have a different and less beefy axle if I was reading correctly on other sites.

4.10's would be plenty low gearing for this truck. I suspect however that the 3.73's will work just fine for my needs. I will make that decision when I get the AT Overland truck topper and build it out how I want.
 

GPurcell01

Active member
Waiting to hear back about whether or not the tires will be here today! Loving these wheels.

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Method's "bead grip" technology. No idea if it's any good or not but you can see the four ridges on both bead lines on the wheel. Definitely looks like it would hold the bead better.

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tienckb

Adventurer
Clean finish on the wheel.

I for one am not into simulated bead lock look.

I am set on running 18” wheels and +18 offset for flush look.

Well done!


Sent from my iPhone using Tapatalk
 

GPurcell01

Active member
Tires will not be here until tomorrow. Still went ahead and tinkered with the new wheels. I am sooo happy that I didn't go with black. The titanium grey looks fantastic. These will look so good.

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As CJC Offroad noted, these wheels really are the perfect offset.

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Thuren took more of my money today... now we wait...
 

Explorerinil

Observer
Yes! This was another benefit of getting the HO. The axle is the same on these newer trucks for both the dually and SRW. Hemi or standard output trucks have a different and less beefy axle if I was reading correctly on other sites.

4.10's would be plenty low gearing for this truck. I suspect however that the 3.73's will work just fine for my needs. I will make that decision when I get the AT Overland truck topper and build it out how I want.
Put a load on the truck on a hill and if your trans downshifts allot you’ll want gears. As for the axles, yes all HO cummins trucks should have the 11.8 ring gear… everyone and every piece of litature I read said that, when I did my gear swap, my truck had the 10.8 ring gear (my truck was an HO cummins with the Aisin) and I did the conversion to 11.8. I talked with a tech at nitro gear and he told me he has seen the SRW HO trucks often with 10.8 gear sets.
 

Tex68w

Beach Bum
You haven't mentioned that Ram returned to the Bosch CP3 reliable injection pump. Both Ford and Ram have had issues with the CP4.

Exactly why I went with a 2021, the CP4 in the 2019-20 trucks was a disaster.


Tires will not be here until tomorrow. Still went ahead and tinkered with the new wheels. I am sooo happy that I didn't go with black. The titanium grey looks fantastic. These will look so good.

View attachment 683262

View attachment 683263

As CJC Offroad noted, these wheels really are the perfect offset.

View attachment 683264

Thuren took more of my money today... now we wait...

I ran those on my Lexus GX, they are a nice looking wheel indeed. Make sure you paint the hubs on the axles if you go without the center caps, I've personally never been a fan of center caps on the RAM's. What else did you order from Thuren?
 

GPurcell01

Active member
I ran those on my Lexus GX, they are a nice looking wheel indeed. Make sure you paint the hubs on the axles if you go without the center caps, I've personally never been a fan of center caps on the RAM's. What else did you order from Thuren?

The center caps have already made their way to the trash lol. Still no tires yet even though I was promised them yesterday.

Fox 2.0 remote reservoir shocks front and rear
2.25 coils
Adjustable track bar
King steering damper with black anodizing
 

Tex68w

Beach Bum
The center caps have already made their way to the trash lol. Still no tires yet even though I was promised them yesterday.

Fox 2.0 remote reservoir shocks front and rear
2.25 coils
Adjustable track bar
King steering damper with black anodizing

Very similar setup to what I am running on my 3500, you'll be pleased.
 

GPurcell01

Active member
And she's now on 37's. Had to grind down the pinch weld up front and sealed it up with POR 15 Patch. Really good stuff. I'm letting it dry overnight then will re-install the fender liners in the morning. That's why it's missing some lug nuts up front. I have a feeling I didn't take enough off but I figured it's easier to grind off more if I need to, than take it too far lol.

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All sealed up...

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And the other side. Tire is definitely closer to the cab on the passenger side than the driver.

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The perfect offset and tire poke in my opinion.

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GPurcell01

Active member
Keep in mind that this is with a 37x13.5 wide tire. If I had gone with the usual 37x12.5, I bet it would've fit with zero rubbing. Other than that pinch weld, I have no issues.
 

GPurcell01

Active member
All put back together and she's gorgeous. I do have minimal plastic rubbing in the wheel well where the pinch weld used to be but I'll let that self-clearance. Not too bad that 37's fit on a stock height Ram HD.

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The Hypertech got my speedometer back to GPS accuracy within 1 mph. I'm happy with that.

The last thing I'll be playing with is pressures. Currently have 60/50psi front/rear. I may drop it to 50/40 and see how that is - however I do have a great contact patch on the tire currently.

Method's bead grip technology gave the tire guys a little run for their money trying to get the tire to seat. Lots of lube and lots of air were required before the tire would finally seat with a loud "bang!"
 

Tex68w

Beach Bum
I am running 48psi in the rear and 44psi up front, seems perfect for daily use. I bump it up to 65/60 when towing heavy. I’m running the same coils, same offset Methods and 37x12.50’s and no rubbing at all. That said, the difference in tire and the lack of fender flares might be the difference maker.
 

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