f250 tranny / rear end

[kiowa]

I jjust got an 85 f350 diesel with a manual 4 speed. when i go 60 on the highway the rpms are really high. i think i should switch the tranny or pumpkin. Any suggestions or info would be great.

[wrkey]

Originally Posted by kiowa

I jjust got an 85 f350 diesel with a manual 4 speed. when i go 60 on the highway the rpms are really high. i think i should switch the tranny or pumpkin. Any suggestions or info would be great.

You might be able to switch out the rear end gears for a smaller ratio. I suspect you probably have a 4.10 set now. However, remember that your truck is heavy which requires a lot of torque to make move and the diesel certainly has the required torque. The set up that you have is designed to take the stress of all that torque. If you got to a different gear set you may find yourself replacing the gears before to long. Especially if you pull or haul anything really heavy... which is why you would have a big diesel anyway.

You also might be able to find an 'overdrive' kit that fits your tranny which would be the best way to do this as then you'll only use it when you are unloaded and cruising.

Hope this helps!

[alpurl]

what about the possibility of a slipping clutch?