I was wondering if anyone has changed the stock 4.10 gears with anything higher to improve MPG. I never tow and was thinking of going with 3.43.

Anyone?

 

I'm not a gear expert by any means but dropping down that low would definitely increase MPG on the top end but you'd never get a 2 moving with those gears......

 

The problem with the equation is that there isn't enough HP to push it. With a 3.43 ratio there won't be enough engine power to keep the transmission in higher gears. So when you're cruising down the highway, your transmission will be lugging and constantly shifting from 3rd to 4th and the only time it will stay in fourth is while you're not under any load like level roads or downhill. This will eventually burn out the 3-4 clutches in your trans. It's the same as running large tires on stock gears. I have 40" tires on mine and had 4.10 gearing. When I bought it it had just had the trans replaced. With the 40's and stock gears, I burnt the 3-4 clutches out in 30,000 miles and got 8 MPG while doing it. I rebuilt the tranny and installed 4.88 gears and my MPG is improving. You might get away with running 3.43 if it weren't full time 4WD and so heavy. The key is to keep the RPM's down and if you don't have the power to push it in higher gear then it's going to kick down to a lower gear and run up the RPM's.