Truckchief

Ya your right, its to bad there arent more J10's or J20's around in halfway decent condition.

Well I have working trailer brakes and I also have a friend thats going to sell me a Chrysler 8.25 to use. I was pretty sure that the Jeeps are good to pull 5000lbs from the factory. They usually come with 3.55 or 3.73 with a towing package I think. Also when you pull 5000lbs don't forget there is a tongue weight that gets transfered onto the rear axle of the vehicle. Real over the road Truck Drivers also have braking issues. How do they deal with it? They start slowing down alot sooner than cars and they usually don't follow as closely. I agree with you though a bigger truck would be better but I don't have the money to buy one and I don't want to sell my comanche. Thanks, -Ken :chillin:

Whats recommended instead of a Dana 35c for towing?

I'm located in western New York

Hi, I was wondering if anybody see's a problem with switching my 91, 4.0ho, 5spd, 4x4 Comanche to a 4.10 final drive ratio. I want to do this because i'd like to be able to tow 5000lbs. I've already towed with it currently and the 3.07 gears are just to high to tow with. It struggles at low rpm and makes the 4th and 5th gear almost useless unless you get going really fast. I've made a spreadsheet using the transmission ratios, final drive ratio's, and tire size as inputs to determine engine rpm at any speed. I also calculated the rear wheel torque with several different final drive ratios using an input engine torque of 200ft-lbs neglecting driveline resistance. Results at 65mph in 5th gear Final Drive Ratio Engine (RPM) Rear Wheel Torque 3.08 1898 489ft-lbs 3.55 2188 564ft-lbs 4.10 2527 651ft-lbs 4.56 2811 724ft-lbs 4.88 3008 775ft-lbs Results at 10mph in 1st gear (assume 175lbs engine torque) Final Drive Ratio Engine (RPM) Rear Wheel Torque 3.08 2124 2064ft-lbs 3.55 2448 2379ft-lbs 4.10 2827 2748ft-lbs 4.56 3145 3056ft-lbs 4.88 3366 3271ft-lbs Based on these results I think that 4.10 would be reasonable for highway towing. But if anybody has any insight or experience with changing their final drive ratio for this reason please let me know what you think. Thanks, -Ken