Gear ratios

[Bootless]

So i plan on 31s for now 35s in the future what gears should i run

 

[corkey]

31's work best with 373 or 410,,
35's need 488 or 513,,

i have run 35's on 410 gears after switching from 373 it kinda works, but it's very lazy and not good for fuel mileage,,

 

[RangerX]

I run 4.56 with 35's, and ran 37's for 12 years, also on 4.56. That included a good amount of serious off-roading. You wouldn't NEED any higher, but it also wouldn't hurt.
What ratio do you have now, and how much time between getting 31's, and going up to 35's?

 

[Bootless]

3.27 rigjt now and there will be a big gap in time

 

[96EXXLTinCO]

I'm running 3.73's............when I went to a 31" tire from the stock 235's, there was a very noticeable loss of power. Sucks driving it in town with the loss of power as well as up into the mountains on the highway. I either have to downshift clear to 3rd and crawl up the hills, or go in 4th with the motor screaming. but I do get better mileage on flat highway. If you're planning on staying at 31's for quite a while then go for now higher than 3.73, but preferably 4.10 If you think you could get to 35's fairly soon, then I would just wait and go with 4.88's and 35's at the same time.

 

[2stroke]

From my calculations, 3.73 on 31's is equivalent to 3.49 on stock tires, very close to 3.55. I have 3.27 on stock tires now, and its no power house, but I don't have to wring the motor out just to accelerate. Where you live is a big factor. Being as 96EXXLTinCO most likely lives in the mountains, he needs more power than the flat lander's like myself. My vote goes for 4.56. Not too much for 31's, should be ok for 35's according to my calculations. Plus in my recent search for 4.10, 4.56 is everywhere and often the cheapest gears. I've never actually ran the setup. 4.56 with 31's puts you just over 2,100 rpm in over drive at 55 mph. With 35's it drops you to just over 1900 rpm.

 

[Bootless]

I was thinking 3.73 how hard is it to change

 

[2stroke]

I'll let you know in a month or so when I do mine, but its a very precise process. It is one of the more advanced skills to working on cars. Don't swap to 3.73.

 

[malohnes]

From my calculations, 3.73 on 31's is equivalent to 3.49 on stock tires, very close to 3.55. I have 3.27 on stock tires now, and its no power house, but I don't have to wring the motor out just to accelerate. Where you live is a big factor. Being as 96EXXLTinCO most likely lives in the mountains, he needs more power than the flat lander's like myself. My vote goes for 4.56. Not too much for 31's, should be ok for 35's according to my calculations. Plus in my recent search for 4.10, 4.56 is everywhere and often the cheapest gears. I've never actually ran the setup. 4.56 with 31's puts you just over 2,100 rpm in over drive at 55 mph. With 35's it drops you to just over 1900 rpm.

I concur. I'm about to swap gears to 4:56. It's a good compromise for your current needs You might find that 37's could use lower gears but with 31's it'll move well. I'm hoping to move up to 33's myself after more mods, and engine/tranny work.

 

[96EXXLTinCO]

Altitude will play a small part in my power issue, but if I was into some 4.10's with these 31's that's as close to stock final drive ration as I could get. In 1st and 2nd gen explorers, to stay as close to stock as possible:

For 31's go to 4.10
For 33's go to 4.56
For 35's go to 4.88

It's not recommended to go deeper than 4.88's in a 8.8" rear, the pinion gear starts getting too small at that point and you start losing strength and reliablilty exponentially. As I said before, it's all about how you use your Explorer, mostly in town, a lot of highway etc. You'll hate 31's with 4.56 on the highway, either mileage will take a dump from running higher RPM's, or you'll just have to go slower.

 

[mr cribb]

For 31's go to 4.10
For 33's go to 4.56
For 35's go to 4.88

This is a nice guide to have

 

[Rhett]

What about the gear ratio for 32's? Probably 4.56?

 

[malohnes]

Rhett, that would depend on your choice or need. Better mileage vs more pulling power. I choose lower gears for power at the expense of mileage. I haven't installed the gears yet and I don't have 33's either, but from my research it seems best. You're interested in 32's which will either be a slightly lower 4.56 or a stlightly tall 4.10.

4.33's are an option too, but it's quite a bit pricier. I recall JD talking about this a while back in another thread.

 

[Rhett]

I am sick of tall gears (31's and 3.27!) and lugging below the power band (auto trans).

The real decision I'll have to make is 31's or 32's. If I go 31's, it'll be 4.10. If I go 32, 4.56.

 

[malohnes]

I think you'll like the extra gears. I can't wait to swap mine out. I understand, I have 3.55's...not as bad as your combo but bad enough.