Gear ratio advice 3:73 or 4:30 on Super Duty
I am in the beginning stages of looking for a new TV and was looking at the Fords to start off with. (Dont worry Dodge fans I will look at them next) I see that Ford has either the 3:73 or 4:30 gears ...
Forum Discussion
I'm not sure I can agree with this thinking. It would mean I should get 3.55's and just run the transmission in 4th gear or 3.31's and run in 3rd the way you are describing it?
Higher ratio final drives also put the gear ratios closer together so the transition between shifts is less severe. I have always chosen my top cruising speed and geared appropriately for my typical load to prevent transmission hunting. This is typically close to where you develop maximum torque. I run 1700 RPM somewhere around 55-60 mph which is just fine for my CTD. The PSD develops torque at 1600 RPM, so you can do the same math to find the ideal final ratio.
Higher ratio final drives also put the gear ratios closer together so the transition between shifts is less severe. I have always chosen my top cruising speed and geared appropriately for my typical load to prevent transmission hunting. This is typically close to where you develop maximum torque. I run 1700 RPM somewhere around 55-60 mph which is just fine for my CTD. The PSD develops torque at 1600 RPM, so you can do the same math to find the ideal final ratio.
