Good Evening, I have an 06 Ram Quad Cab 5.7L Big Horn w/ 3.92 Gears. Tow Capacity is approx. 8600lbs. Can ANYONE tell me what the towing capacity will be if I install 4.56 gears....Also as a bonus Q: Any idea what the new torque would be? Thanks

 

Is 3.92 the highest factory gearing available? If so, it's 8600lbs.

 

Towing capacity is not increased with a gear upgrade.
Towing capacity is governed by what frame/chassis you have, along with suspension and braking components.
That's why there are 1500, 2500, and 3500 models.
An increase in gear ratio will however, help pull the max load easier. Due to a better mechanical gear ratio advantage. Thats all.
Cant help you with a torque figure. But i have read that going from 3:55 to 4:56 is almost like bolting on 100hp on a heavy *** QC.
Maybe thats a bit high but, everyone rates that upgrade and its one im desperate to complete myself.
Al.

 

Had 3.55's. Went to 4.56's. Night and day difference!! Not sure what the added torque would be but pulls my 30 ft travel trailer way better. With factory 265/70 r17 tires run at 2100rpm at 65. With o/d locked out in 3rd I'm running around 3100. Perfect for pulling hills!! Can't go wrong!!

 

Technically, AL is 100% correct.


From an insurance/legal standpoint, the tow rating is what the manufacturer sets it as. However, in practice you can generally add about 1000 lbs. in capacity going from 3.92s to 4.56s. When I did my '04 after lifting it the difference in towing about 7700 lbs. of trailer/tractor/rough cut was night and day.


But if you are towing over the rated capacity, Mr. Policeman ain't gonna want to hear how you changed gears and worse, an insurance company is within their legal rights to deny a claim if you are over rated capacity.


As far as adding torque, changes to the rear axle will not increase the torque output at the crank. Ain't happening...