Originally Posted by tmsbandman
Yeah. Not happening in the forseeable future, anyway. I'm not sure I have the guts to tackle it, and it's an 8 labor hr job I can't afford. Thanks for the advice. Might not be worth it if I can't use OD. Engine would tach pretty high in 3rd with 4.10.
The reason you shouldn't use overdrive has nothing to do with overdrive itself. The problem is it makes the gearing to tall. If you installed 4.1 gears that would shorten the gearing to the point where you could use all your gears.... and more gears is better.
I have an Expedition with a 5.4 and 3.73 gears. At 60 mph it's turning over around 1800 rpm which is great when running empty but too low when towing my trailer. If I leave the OD off it's around 2500 which is great for torque and tows with ease. Downside is it's now just a 3 speed auto. 4.1 gears would bump the rpm to around 2100 at 60 in OD which means I could use it on the hwy.
My truck is a 4wd though which doubles the cost of changing gears and my trailer is lighter so for me it's not worth the effort. In your case it might be.