Gears and Tires

[bidibronco]

I was told that anything bigger than 35" tires on my Bronco requires new gears due to the wear it will put on stock. I want to go with 38" tires. Anyone have any suggestions on what gears I need to go with. I plan on doing both front and back since I want 38's all around. Thanks for any suggestions. @-)

 

[Broncoboy07]

are you running stock gears? what gears do you have now?

 

[Justshootme84]

Any size tire larger than stock will affect the final drive ratio, and changing gears is the right way to return to "stock" to stay within the engine's power band. Most folks running less than a 33" tire don't bother with new gears, since the effect is slight unless you have something like 3.00:1. There's several charts and formulas to figure what ratio is needed for what size tire, and whether you drive on the street, tow a trailer or want a little better gas mileage. The range for 38's is a 4.88:1 up to a 5.12:1. Different brands of a 38" tire will vary slightly in the actual height, too.

My advice before buying a new set of gears is to research what effects that big a tire will have on your stock axles, transmission, ball joints, etc. A 35" tire is the tallest I would run on the stock Bronco axles, and even that causes more wear and tear on those parts.

 

[S_bolt19]

You want to make sure you have all the parts that are going to be strong enough to handle treads that big. If you have a 9" big bearing under the rear you should be ok unless you are lead footed. Most guys who go with anything bigger than a 35" go with something like a dana 60 because of the strength. The smaller 1/2 ton axles will break a lot easier unless you go to like a nodular 3rd member 35 spline axles, etc. I would stay within the 35" tire range because of costs and parts upgrades. You are looking at somewhere in the neighborhood of $1500 in tires then another $2-3k for parts that can handle those tires.

Like it was said before, do your homework before you get in too deep.

 

[bidibronco]

Thanks for all the info, with all that said, I think I'll just keep things simple and get some 35's and put something bigger on a trail only rig I want to build. Again, thanks for all the info.

@-)