Gear Ratio Help

[soccerking09]

so ive seen the gear ratio chart and im pretty sure ill be goin with the 4.10 but i just want everyones opinion. i have a 4 cylinder runnin on 31" tires and a 5" lift so i dont have much power at all. im not too concerned with my mpg. im more concerned about gettin a gear ratio too high and mess something up. anyone have good advice for me?

 

[soccerking09]

oh and ive read that if i change my rear gear ratios that i should change my front ones too? im not great with trucks but im tryin to learn so can someone explain that too?

 

[4.0B2]

you MUST have matching gear ratios front and rear...if not, bad things happen. usually a transfer case will explode.

for a 4 banger and 31's, 4.10 is the highest (numerically lowest) I would even think about... You might even consider 4.56's.
What is your primary goal of the ranger?
is it a DD? dedicated off road? a little road and a little trail?

do you ever plan on going to 33" tires?
what transmission do you have? auto or stick?
what's your axle code on your door sticker now?

 

[soccerking09]

i want to run 33s in the near future but my 31s are only about a year old. i use my truck as my daily driver but i want the power for offroadin which is basically my goal for the truck. i have a manual transmission. i had looked into the 4.56 but i wasnt sure if it would be to high of a gear ratio.

 

[soccerking09]

right now im running the 3.73 gear ratio. you think i should get rid of that asap? i lost so much power and speed ever since i lifted it and threw 31s on it

 

[4.0B2]

what's your stock gears? if you don't know, what's the axle code on your door sticker?

I'm hoping someone with a 4 banger will chime in, I have a 4.0 in a Bronco 2; but I'm running 4.56's for 33's. If you're thinking about larger tires in the future, gear for them now.. gear once and done b/c having gears installed is crazy expensive. I'd gear for 33's now and just deal till you upgrade tire size.

edit: you answered it.

 

[4.0B2]

a 3.73 to 4.10 swap is NOT a huge deal... You probably won't even notice the difference between the 2. Personally, I'd be looking for probably 4.88's. idk... I have the 4.0 so... just wait till someone else chimes in.

and remember, the higher the number- the lower the gear... people get confused if you say 4.56's are to high compared to 4.10's. (not complaining, just clarifying to keep confusion down)

 

[soccerking09]

ok so ill probably look into the 4.56 then. i just wasnt sure if my rpm's would be too high with that. now for my front gear ratio it would also have to be 4.56 right?

 

[4.0B2]

ok so ill probably look into the 4.56 then. i just wasnt sure if my rpm's would be too high with that. now for my front gear ratio it would also have to be 4.56 right?

yes. front and rear must match.

do you know what model transmission you have? I can look up to see what your RPMs will be at different speeds. Here's the link I use
http://www.grimmjeeper.com/gears.html

 

[soccerking09]

no im not sure what transmission i have. and i appreciate the clarification. im not too great with vehicles but im tryin to learn lol so thank you!

 

[scotts90ranger]

being a 4 cylinder and a '99 it's 4x2 not 4x4 so you don't have front gears so don't worry about that part...

that said, go 4.56, I drove for a few years with 31's and 4.10's and it was OK, but not optimal, going offroad involved a lot of clutch slipping...

Also, you're going faster than your speedometer says, so you didn't lose speed, and instead of loosing power it basically just moved the speed at which you shift, I drove for a while with 3.08 gears and 28" tires so that was worse than what you have and it wasn't that bad I just lost the use of 5th gear, 3000rpm in 4th gear was like 65mph in that setup.

 

[4.0B2]

best I can figure, with 31's and 4.56's; at 65 mph in 5th gear you'll be at 2538 RPMs.. but when you step up to 33's; same speed/gear you'll be at 2384 RPMs.

31's and 4.88's; same speed/5th gear; 2715 RPMs
33's and 4.88's; same speed/5th gear; 2551 RPMs

idk what RPMs you wanna be at... but I think either choice would be okay for you. However, if you are mostly in town driving and see very little 55 MPH or more speeds, i'd be looking for 4.88's.

and you'll need to calibrate your speedo after regearing and changing tire size

 

[soccerking09]

thats what i was thinkin with the front gear ratios but i just wasnt sure. and youre right,i pretty much think my 5th gear is useless. so how can i fix my spedometer to be right with my actuall speed? idk if i should be askin that question somewhere else....? lol

 

[soccerking09]

well i want to take care of my engine as much as possible right now. i blew it out and it got rebuilt earlier in the year so i dont want to push it to much. and thanks for doing those calculations for me

 

[4.0B2]

yeah if it's not 4 wheel drive, then no need to worry with front gears (they ain't there)

no problem. glad to help. I'd at least go 4.56's if I were you, if not even 4.88's. Read around here and see what people are happy with.