2009 Dodge Truck Tire:Axle & Gearing Problem

GOMUJOMO

MEMBER
2009 DODGE TRUCK
V8
4WD
AUTOMATIC
4,500 MILES

Hey,

My name's Gordon and I own an '09 Power Wagon, that I wheel. I think I have AAM 9.25-inch front and 10.5-inch rear axles, and I need to know what size tires they can accomodate. I am worried about them breaking. As far as I know this is identical to the dana 60/70 setup, and my friend roll's 40's on his and has never had a problem.

My plan is to use 42s and change my gear ratio to 5.8 or use 38s with a gear ratio of 5.25. I don't think I will have any problems with 38s but I would rather use the 42s.

Also, what is required to change my gearing, and what is the lowest gearing possible on these axles (I have 4.56 now)? 'Cause this will also limit the size of tires that I will settle on.

I know it's a big one, but I appreciate the help. Thanks.

2 Replies

RACEFAN966

MECHANIC
5,029 POSTS

Ok this is a trick question because I don't know your driving habits. How you take off and so on. Now as you know you will need to get a programmer to change you speedo to keep it calibrated. As for the AAM brand good brand but is only factory. Now I would check with Tom's Differetial's he is on line. You can check all the gear ratio's for your diff's. Now also keep in mind that if you want to make them stronger you can ask a good gear shop as to weather or not they recommend heat treating. With doing the lift correctly putting on ladder bars and such to control roll of the diff there is no reason you couldn't run 42's.