Cummins goes to 1075 lb-ft

[DeansRedRam]

To my understanding it doesn't actually hang lower than the differential, but extends outward like you said to catch air. Although I do agree about the hitting road debris and whatnot, definitely a downfall.

I personally really like the way the aftermarket covers look, but the flat back doesn't do it for me. I think I'd rather run the stock cover over a flat back due to the way oil comes off the ring gear.

Although if stock cover had a drain plug and easy fill, I probably wouldn't bother changing it at all.

 

[Ltngdrvr]

All a good aluminum cover needs is fins to dissipate the heat, like the stock AAM finned cover.

And, none of these trucks probably NEEDS an aluminum cover, just needs periodic oil changes if used heavy.

I put one on mine, the AAM cover, way back when they were still selling them cheap, less than $100, but I didn't need it, just some bling that you can hardly even see.

 

[Ben_Stadelman]

https://www.cummins.com/news/releas...eavy-duty-legendary-pickup-engine-better-ever

 

[AH64ID]

So we have “official” sheets showing 400, 420, and 430.

Gotta love modern marketing.

CP3, CP4, or C-3PO?

 

[DeansRedRam]

So we have “official” sheets showing 400, 420, and 430.

Gotta love modern marketing.

CP3, CP4, or C-3PO?

I’m always amazed at how de-tuned these engines are. A simple adjustment to fuel and air and these engines bump 75ft/lb torque and who knows the hp but 30 sounds good to me!

 

[NIsaacs]

Ok, so I had to run an errand and the Ram dealer was a 1/2 mile down the road so I stuck my head up some skirts.

All 2500/3500 trucks have the same housing. Obvious width difference between SRW/DRW and suspension hard points. All are the same pumpkin and axle tube diameter. This is what I had noticed previously, but measured and verified today.

What I learned today is that only the HO and/or DRW trucks get the axle stuffed with the 12” R&P vs the 11.5” R&P.

So, just like the 11.5 vs 11.8, the axle is the same the R&P is different.

The above report is pretty plain and to the point, tape measure and pictures.....but are you sure What exactly are the measurements on all the axle tubes? Were they all 4.250". Was the dually pictured a max tow?

Copy and paste from Rams spec sheet on the new 2019's.

"The Ram 3500 Heavy Duty with the Max Tow Package uses an all-new, larger 12-inch AAM rear axle with 4.25-inch axle tubes, larger head, tail and differential bearings, and new O-ring style axle shaft hub seals. The limited-slip differential uses a friction plate design, while the serrated axle pinion and driveshaft flanges are upgraded to handle the increased torque."

This implies the 2500/3500 SRW and non max tow dually get a different axle.

 

[TFucili]

Hard to separate actual changes from fluff in that press release. When the '19 was rolled out they already said they were at 2K Bar rail pressure, and that they had doubled the processor capacity of the controller for the freshly tweaked Aisin.

 

[AH64ID]

The above report is pretty plain and to the point, tape measure and pictures.....but are you sure What exactly are the measurements on all the axle tubes? Were they all 4.250". Was the dually pictured a max tow?

Copy and paste from Rams spec sheet on the new 2019's.

"The Ram 3500 Heavy Duty with the Max Tow Package uses an all-new, larger 12-inch AAM rear axle with 4.25-inch axle tubes, larger head, tail and differential bearings, and new O-ring style axle shaft hub seals. The limited-slip differential uses a friction plate design, while the serrated axle pinion and driveshaft flanges are upgraded to handle the increased torque."

This implies the 2500/3500 SRW and non max tow dually get a different axle.

It was easier to measure circumference, which came in at 13 3/8. 4.25xpi=13.35. I called the .025 difference close enough for on the ground under a truck in 22° weather

The spec doesn’t state that the axle is only used on the max row thou, so to me it doesn’t imply it’s not used on non-max tow. It just says it uses it. Remember max tow is an option package and not needed to get the max GCWR, on HO/4.10’s are needed for that.

Even the 11.5” trucks in the 12” housing get the friction plate LSD.

I do believe that truck was a max tow thou, it had the air suspension, 5th wheel prep, 4.10’s, HO, etc. just didn’t look further at the spec sheet since that option package doesn’t matter for ratings.

@TFucili is yours a “max tow” or just a 4.10/HO?

 

[TFucili]

It was easier to measure circumstance, which came in at 13 3/8. 4.25xpi=13.35. I called the .025 difference close enough for on the ground under a truck in 22° weather

The spec doesn’t state that the axle is only used on the max row thou, so to me it doesn’t imply it’s not used on non-max tow. It just says it uses it. Remember max tow is an option package and not needed to get the max GCWR, on HO/4.10’s are needed for that.

I do believe that truck was a max tow thou, it had the air suspension, 5th wheel prep, 4.10’s, HO, etc. just didn’t look further at the spec sheet since that option package doesn’t matter for ratings.

@TFucili is yours a “max tow” or just a 4.10/HO?

I didn't want their fiver hitch, so I ordered 4.10/HO. I did have an email from Ram stating it's the same, as there was, and apparently still is, confusion about the Max Tow name, but I deleted that email long ago.

 

[AH64ID]

I didn't want their fiver hitch, so I ordered 4.10/HO. I did have an email from Ram stating it's the same, as there was, and apparently still is, confusion about the Max Tow name, but I deleted that email long ago.

I don’t blame you, I wouldn’t want that hitch either.

 

[Wiredawg]

I hear y'all about not wanting the hitch, but what I think is good is that a buyer can get a fully capable tow rig without going to the aftermarket. Not trying to start a hitch war, but just saying on all my Ram trucks to current 2017, had to have after market mods to get a tow ready rig.

I play with the Ram truck builder when I'm reconstituting from project pain, and find it interesting what packages and options selections drives other options and deletes.

I played on the Ford site too, interesting how they play the options game too.

So, I guess we'll see who the first 2021 truck owner is and get the butt in the seat skinny on the truck.

Merry Christmas Cheers, Ron

 

[NIsaacs]

It was easier to measure circumference, which came in at 13 3/8. 4.25xpi=13.35. I called the .025 difference close enough for on the ground under a truck in 22° weather

The spec doesn’t state that the axle is only used on the max row thou, so to me it doesn’t imply it’s not used on non-max tow.

Yes, that's why I asked. Did you lay on the cold dirty ground and get an exact measurement on each axle or did the cold day say, that's close enough

The spec sheet was clear about "for the Max tow". If they were all the same, why not say "all trucks get it".

I am not convinced...yet

 

[AH64ID]

Yes, that's why I asked. Did you lay on the cold dirty ground and get an exact measurement on each axle or did the cold day say, that's close enough

The spec sheet was clear about "for the Max tow". If they were all the same, why not say "all trucks get it".

I am not convinced...yet

Surprisingly the ground was quite clean, but then again it always has new rigs parked on it...so those shouldn't be leaking anything

It also doesn't say exclusive to the max tow, it just says it uses it. I haven't been able to find it again, but I read an article about the R&P differences for the DRW (stated all DRW) having more ring gear bolts to handle the higher GCWR. The GCWR on the 3.73 trucks is still over 40K lbs, they aren't using a weaker axle with the same HO motor.

Stop by your local Ram dealer and stick your head under there with a tape of your own. You'll find the same thing I did, 4.25" housing on everything. Guts may vary.

Take a look at this chart thou, it shows 11.5" R&P on DRW with the 68RFE. Says the 12" is included with the max tow package, but also lists one 12" version as SRW only.

https://www.fcausfleet.com/content/...ide/2021/2021_Ram_Heady_Duty_Buyers-guide.pdf

So now it appear that 12" is exclusive to HO, SRW or DRW. Which makes me wonder if there really is a difference in the R&P SRW to DRW or if the article was referring to 11.5/11.8" vs 12".

EDIT: Sure enough here is a 2021 DRW 68RFE build sheet showing a 11.5" axle.

https://www.jeep.com/webselfservice/BuildSheetServlet?vin=3C63RRRL9MG517651

On a side note, why option a 87K limited DRW with a SO motor???



But I think it's safe to say gas/SO = 11.5", HO = 12".

 

[JPM]

forget the torque wars ,whos gonna break $100,000 on a 3500?

 

[NIsaacs]

Surprisingly the ground was quite clean, but then again it always has new rigs parked on it...so those shouldn't be leaking anything

But I think it's safe to say gas/SO = 11.5", HO = 12".

I agree.

But I also think the 11.5 ring gear and carrier assembly will not fit this:

"larger 12-inch AAM rear axle with 4.25-inch axle tubes, larger head, tail and differential bearings," It don't stand to reason they will interchange.

 

[AH64ID]

forget the torque wars ,whos gonna break $100,000 on a 3500?

Ram is close. Just optioned a 2021 Mega DRW HO Limited at $95.5K.

I agree.

But I also think the 11.5 ring gear and carrier assembly will not fit this:

"larger 12-inch AAM rear axle with 4.25-inch axle tubes, larger head, tail and differential bearings," It don't stand to reason they will interchange.

I don't know why it wouldn't fit.

As you can see in my above photos the housings are the same. Measured 4.25" axle tubes on a 2500 gas, 2500 Cummins, 3500 SO/HO. I can't see a single reason to have the axle housing the same externally but not internally. Just bolt in the required carrier etc and go on.

 

[DavidC]

forget the torque wars ,whos gonna break $100,000 on a 3500?

Gonna need at least a 30 year mortgage, probably more.

 

[DeansRedRam]

I'm a graph kind of guy, or maybe I'm just a simpler guy...

Gas 2500 - 11.5"
Gas 3500 SRW - 11.5"
Gas 3500 DRW - 11.5"

Diesel SO 2500 - 11.5"
Diesel SO 3500 SRW - 11.5"
Diesel HO 3500 SRW - 12.0"
Diesel SO 3500 DRW - 11.5"
Diesel HO 3500 DRW - 12.0"

Did I get this right?

 

[Cummins12V98]

I don’t blame you, I wouldn’t want that hitch either.

You mean the Communist Chinese Curt model?

 

[AH64ID]

I'm a graph kind of guy, or maybe I'm just a simpler guy...

Gas 2500 - 11.5"
Gas 3500 SRW - 11.5"
Gas 3500 DRW - 11.5"

Diesel SO 2500 - 11.5"
Diesel SO 3500 SRW - 11.5"
Diesel HO 3500 SRW - 12.0"
Diesel SO 3500 DRW - 11.5"
Diesel HO 3500 DRW - 12.0"

Did I get this right?

That’s what my research has shown.