OK this is my situation. I have a 2003 Ram 2500 with the 5.7 and 3.73 gears in it. I have 265 70 R17's on it for tires. I want to change the gears in it for better pulling and more off the line start. The question I have what gears do you all think I should run? The next factory size is 4.10's, is that good enough? I was told by someone else to run 4.56's, is that too much? If anyone has some insight on my situation please let me know so I don't make a costly mistake.

Thanks!

 

if you only plan on running the stock size tires, then 4.10's will work. I have 4.56 and with 295/70-17 tires I am @ almost 2000 rpms at 60 MPH.

 

I wouldn't go 4.56's for 31.5" tires which is what 265/70/17's are. You'll be spinning too many rpms at highway speeds.
Guys who have 33's and upgrade to 35's install 4.56's Not the guys with 31.5" tires.

With 4.10's and 265/70/17's you'll be running the near the same rpms asakguy09 has posted.(slightly less)

 

What would you think if I where to up my size to a 285 in the future? Think that the 4.10's will still be good?

 

285 is the width of the tire, so stating just that isn't suffuccient. If you have a 265/60 tire and a 285/06 tire, the 285 will be 2mm's wider and 1.2mm taller if you were to compare them to one another. (It takes 2.54cm to make up one inch. It takes 100mm's to make just 1cm, so... 254mm = 1")

Picking tires to aid your gears is not the way it works...lol You would need to go to extremes for a good bit of difference.

I think you ned to figure out if $1000 is something you want to afford because gears are NOT cheap. Even more expensive for 4wd because it's 2x's axles not just one.

 

My personal rule of thumb is 4.10s for stock to 33" and 4.56s for anything over 33". My 4.56s yield about 2100 rpm at 70 on the highway with 35" tires (which actually measure a hair over 34 1/4")...

 

Hate to revive an older thread, but I am really curious what you do ccg... I have the 2500 with 3:73 gears and I find my RAM absolutely mindnumbing with it's shifts while towing (yeah tow/haul turned on). I use factory sized wheels, and wind up getting beside myself angry with how the truck shifts (I HATE automatics).

We'll likely be upping the size of our horse trailer soon (right now empty is #2200, but with 2 horses and all our gear, we're probably pushing #5500)... Either way the 2500 should be walking away with that little weight, and it CAN, but it shifts like mad to do it.

The Girlfriend and I would love to upgrade the tow vehicle but we are stuck where we are for now. I speculated that I could probably pay someone swap gears for $1200 or so (hope I am not far off).

I am just thoroughly interested in what you wind up doing, cost, etc.

 

I use my truck for pulling a 4 place inclosed trailer. The thing is about 25'x9' and it's like a wall when pulling. My truck is a '03 so I don't have a "tow/haul" button, but just the old O/D off button. When pulling this trailor I take it out of over drive. The thing that gets me is when I haul a small two place or even a single 6'x8' trailor and it shifts all the time. I had a '99 1500 with a 360 V* in it jaked up with 35's and 4.56's I also ran in winter 285/75R16's and it wasn't that bad on the freeway just over 2000 RPM, and that thing could pull anything! Of corse it got 10mph even on a good day, just 10 all the time. But with the 5.7 Im getting from 8 to 12 so WTF? So Im thinking running something in between 4.10's and 4.56's. I'll keep you posted when I make the change.