Rear Axle Chart

[CROW]

Assume Aisin transmission, dually, 4 WD. Does anyone have a chart showing tire revolutions at speed for the different rear axle ratios Ram offers? Am aware of the different towing abilities of the axles, but would like to know how much difference there really is and how this might affect fuel economy.
I had a 2005 with a NV-5600 and 3.73. Think I can remember a chart, which I cannot find now but no surprise there, that showed a Aisin with a 4.10 was actually turning less than the NV-5600 with a 3.73. Most of my usage will be solo with occasional towing of a 14K fifth wheel. Thanks in advance.

 

[kthaxton]

Unless I am misunderstanding you... tire revolutions at a given speed will never change regardless of gear ratio....only tire diameter change will do that.

You engine rpm's however, will change at a given speed with a different gears.

 

[CROW]

You are correct. Thanks. I am looking for engine RPM's not tire revolutions.. Chalk it up to a brain fart.

 

[Cummins12V98]

That weight get 3.42's you will be turning 1,750 at 60 in 5th. Bonus you will be around 1,300 in 6th solo.

 

[AnonEd]

655 (std tire approx revs per mile) x 0.63 (aisin top gear) x axle ratio (whatever) will give a good ballpark for rpm@60 mph..substitute 4th or 5th gear ratios as you like.

 

[6V92TA]

Crow, what you do is you use the Find MPH or Find RPM calculator from this link http://www.rocky-road.com/calculator.html

and use these gear ratios from the Aisin transmission, plus figure out your own tire size and you should be able to figure out any question you have. http://www.dieselhub.com/trans/aisin-as69rc.html

 

[SnoKing]

Assume Aisin transmission, dually, 4 WD. Does anyone have a chart showing tire revolutions at speed for the different rear axle ratios Ram offers? Am aware of the different towing abilities of the axles, but would like to know how much difference there really is and how this might affect fuel economy.
I had a 2005 with a NV-5600 and 3.73. Think I can remember a chart, which I cannot find now but no surprise there, that showed a Aisin with a 4.10 was actually turning less than the NV-5600 with a 3.73. Most of my usage will be solo with occasional towing of a 14K fifth wheel. Thanks in advance.

I agree with Cummins12V98. If you are going to run solo most of the time and never exceed RAMs 20,510 tow rating for 3.42 gears. I would get the 3.42 gears. That will give you a freeway cruiser. Towing in tow haul it will not try to shift to 6th unit 65 MPH. I lock my SRW is 5th when towing so that the exhaust brake works better going down hills.

These new RAMs are tuned to perform great at lower RPMs.

Some will be along to say compromise with 3.73 gears. With the Aisin's lower 1st and 2nd gears, there is no reason to compromise.

For the record we tow a 16k 5th wheel at a combine weight of 24,500 pounds in the Western mountains without an issue.

Another question, why are you going dually. A SRW, like mine, will handle your needs fine. SnoKing

 

[gsbrockman]

Another question, why are you going dually. A SRW, like mine, will handle your needs fine. SnoKing

HEAVEN FORBID the OP might *possibly* ever desire to upgrade to a larger RV in the future

Whatever happened to having more truck than is needed for the job.....as opposed to having too little truck for the job???

 

[6V92TA]

maybe the guy likes Dually's? maybe he wants the stability when towing a dually gives a person.? maybe he got a better deal on a dually? there are quite a few reasons to have one, towing heavy stuff is one of the best reasons for owning one instead of making do with a lesser truck or being concerned about appearance.

 

[SnoKing]

It would be nice to hear the OP reason for wanting a dually!

 

[Cummins12V98]

I like the "BIG HIPS"