2019+ Axles

[Big-Cheese]

Ive looked through several forums and threads about this and I cannot seem to find a straight answer. On the 2019 and up trucks, is the 12" rear axle that comes in the 3500 HO diesel SRW trucks the same as the one in the DRW? What is the axle tube diameter on SRW vs DRW? Axle shaft and spline count?

 

[LegendaryLawman]

Wonder if the SO trucks are the same too

 

[AH64ID]

Wonder if the SO trucks are the same too

They are not. SO still uses 11.5” R&P, SRW and DRW.

Ive looked through several forums and threads about this and I cannot seem to find a straight answer. On the 2019 and up trucks, is the 12" rear axle that comes in the 3500 HO diesel SRW trucks the same as the one in the DRW? What is the axle tube diameter on SRW vs DRW? Axle shaft and spline count?

Same axle model, with differences for SRW vs DRW. They are both 4” with 30 spline axles.

 

[LegendaryLawman]

They are not. SO still uses 11.5” R&P, SRW and DRW.



Same axle model, with differences for SRW vs DRW. They are both 4” with 30 spline axles.

Did a little reading, and the 11.5 is plenty HD enough and probably more common of an axle. Never had an issue with my AAM in my 2003 except one leaking rear seal but it was an easy fix

 

[AH64ID]

Did a little reading, and the 11.5 is plenty HD enough and probably more common of an axle. Never had an issue with my AAM in my 2003 except one leaking rear seal but it was an easy fix

The 11.5 is defiantly a good axle, but AAM/Ram deemed it could be improved upon which is why 4th gen's got the 11.8" R&P with the Max Tow and why 4.5 gen's get the 12.0" with the HO.

All the housings are the same 12.0" version thou, just the guts are different, aside from the PW.

 

[Big-Cheese]

They are not. SO still uses 11.5” R&P, SRW and DRW.



Same axle model, with differences for SRW vs DRW. They are both 4” with 30 spline axles.

I thought I read that the DRW axle was 4.25". Which is why I was wondering if the SRW got that as well. I guess I am mistaken. 4" for both?

 

[AH64ID]

I thought I read that the DRW axle was 4.25". Which is why I was wondering if the SRW got that as well. I guess I am mistaken. 4" for both?

So I went and measured my axle. 4.25” seems correct based on the circumference. I have a SRW.

AAM rates the axle the same, regardless of SRW or DRW. The bearings may be slightly different for where the CG of the unsprung weight is, but the axle itself will have the same rating.

I don’t know if they still are different, but GM used to spec a smaller diameter tube for their AAM 11.5” axle and it didn’t affect the rating. It was just what GM wanted. Dodge also spec’d better bearings than GM did.

 

[Brutal_HO]

So I went and measured my axle. 4.25” seems correct based on the circumference. I have a SRW.

AAM rates the axle the same, regardless of SRW or DRW. The bearings may be slightly different for where the CG of the unsprung weight is, but the axle itself will have the same rating.

I don’t know if they still are different, but GM used to spec a smaller diameter tube for their AAM 11.5” axle and it didn’t affect the rating. It was just what GM wanted. Dodge also spec’d better bearings than GM did.

Just from memory on threads RE: new axles years ago, and the quick sticky I did - which admittedly could use a thorough review based on new info, the SRW axle is necked down at the flange, the DRW is not.

2019-2024 HD Axles and Brakes

Current axles are AAM HD pickup front axles is 9.25 CC front axle is 10.5 Standard rear axle is 11.5" ring gear. Only the HO trucks have a 12" ring gear. the 12" axle has 4" tubes. These are necked down at the spindle for the SRW 8-lug hubs. The DRW Max Tow (reportedly) has larger rear...

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