Gears?

[oliveb2]

I have a 1985 Bronco 2 4x4. Its lifted 2 inches with 31 inch tires. I wanted to know the best gears I can get to help out the the strain of the bigger tires, and hopefully increase miles per gallon at the same time. Any help would be apperciated, im not too smart when it comes to these things. By the way its the stock rear end and gears.

 

[alwaysFlOoReD]

I started with 3.45 gears and then went to what I was told were 4.10 but were actually 3.73. I drove those until the rear went. Then I replaced with 4.10. I like the 4.10 the best with the 31" tires I'm running. With my GPS I found I was doing 93 when my speedo showed 100, this has probably saved me from a few tickets.

Richard

 

[trail B2]

I like 4:10s with 31s you could probably find those used somewhere.You really don't know anything though until you know what you have in there now.

 

[alwaysFlOoReD]

I bought mine used.... Make sure to take the cover off and count teeth or check the numbers on the ring gear. You could also [not quite sure of procedure, maybe someone will elaborate] turn the pinion and count tire rotations, or is that the other way around?

Richard

Edit, Count pinion rotations to make one tire rotation; 3 1/2 pinion rotations is going to be 3.45, a little over 4 rotations is going to be 4.10, make sure one axle is blocked from moving. This is assuming the rear is out of the vehicle, don't be dumb and get run over.

 

[oliveb2]

So most people ive talked to around where I live is 4.10's, but will I have any increase in mpg's with changing my gears out?

 

[4x4junkie]

4.56:1 will get you your best power & mileage with 31" tires.
4.10:1 will get you about the same mileage, but less power, however 4.10s like mentioned above can sometimes be found in salvage yards, as it was offered as a factory ratio.

 

[oliveb2]

Thanks guys for all the help. So I have to et gears for the front and rear right?

 

[alwaysFlOoReD]

Thanks guys for all the help. So I have to et gears for the front and rear right?

Yes, if going with the used route, get the front drop out [pumpkin] and the whole rear. It's easier to change the whole rear IMO. I paid C$200.00 for both when I did mine. I've also gotten a whole truck with 4.10 gears minus engine for a flat of beer, so the gods do help some days.

Richard

 

[oliveb2]

Yes, if going with the used route, get the front drop out [pumpkin] and the whole rear. It's easier to change the whole rear IMO. I paid C$200.00 for both when I did mine. I've also gotten a whole truck with 4.10 gears minus engine for a flat of beer, so the gods do help some days.

Richard

Thanks. All info will be helpful in my future plans.