ok im in a delema here. i have 37" boggers for the trail and 31" mud rovers that i use if i have to drive a long way to a trail. what gears should i run in the front and back so i will be able to do 50 down the highway with the 31s but still climb hills with the 37s? because the motor strugels with the 37s and i want to free it up. i have the stock drivetrain with ifs on a 86 reg cab truck 22r. thanks, josh

 

5:29s gears is what you want for 37s as far as driving it with 31s im not sure how it will drive..............also haveing new gears installed isint cheap

 

There isn't any real compromise unfortunately. Maybe drop down to 4.10's for your truck, and then when you put your 37's on just put it in 4 LO all the time? 5.29's will rev like crazy on the highway with 31's - you'll have to keep your speed down to keep your rpm's down.. and you'll probably be doing like 50 MPH on the highway tops.

 

i think he already has 4:10s

 

yea im pretty shure that 4:10 is stock

 

http://www.4lo.com/calc/geartable.htm
Take a look at this chart. It will tell you approx what your rpm's will be with any given tire/gear combo. Note that this chart is at 65 mph, and a 1:1 gear ratio (4th gear in a manual). If you have a 5sp, your rpm's will be lower than the chart says when you shift into 5th. What else are you running? Lift, lockers, etc? I'd like to see it. Pics?

 

thanks for the link i think about 4:79 will be good and the truck is undergoing a small resto right now to get her back on the trail but heres her pics before i started takeing her apart http://profile.myspace.com/index.cfm...endid=76229132 its going to fall in 2 so im fixing the frame right now so shes in pieces then i think a new paint job, gears, rear locker, new rear shocks, belts, fluids, filters and ALOT of tlc. but i got the truck obo 2 or 3 weeks ago and im getting her back trail worthy and a few short drives down some back roads.

 

The solution to your problem is a crawler box or the Marlin 4.7 conversion for your transfer case. The tire sizes are too far apart to make both work with just diff gears.
http://www.marlincrawler.com/htm/transfercase/gears.htm

If you do that, (which is considerably cheaper) you won't NEED to regear the diffs, but if you want to, need to know manual or auto tranny? For 31's:
4.56 with manual
4.88 with auto (may consider 5.29 actually if you're in O/D alot)

For 37's you need 5.71 (only because that's the lowest that will fit in a Toyota axle) and it will be a dog - especially if its auto. Heck - 35's with 5.71's and the 3VZE is a dog!

 

im pretty sure he has a manual ...37s with 4:10s and a 22r that has to be slow

 

Okay, here is some REAL world experience with 37s...as I don't think any of the above posters have them. If you do, my apologies.

I have a 85 w/ a completely rebuilt 22RE, 5 spd, 4.88 gears (ARB lockers) and 37/12.50/15 MT/Rs on black steelies and I daily drove my rig for more than 7K miles before it became a trail only rig. Acceleration was fine, rpms were fine and gas mileage was/is 18-22 mpg on the highway. Yeah, it isn't IFS, but 37s are too much tire for IFS IMO.

I drove it last weekend at Tellico all day long for 2 days straight in 4 Lo and putted over all the trails no problem, locked in the rear only and spontaneously engaging the front locker to play.

4.88s will do you fine on and off-road for 37" tires. This is REAL world experience and I don't need to stay at a Holiday Inn Express.

Again, 37s are just TOO much tire for IFS and a 22RE on a stock non-regeared drivetrain. If you got an automatic...forgetaboutit.

 

o yea i never thought about re gearing my transfer case thats a way better rout and i have a 5spd but i wanted to be able to sometimes run 31s but that might be out of the question unless i do the t case re gearing

 

whats the diffrence between the 21 and 23 spline?? and why are the others more money? because there made diffrent or because they have diffrent gear ratios??

 

Wow, waskilly, you must have a STRONG 22RE!

If what Waskily says is true (and there's no reason to believe it's not), then you could go with 4.88's and be good both ways, maybe a hair low - high rpm on the highway - but not bad

 

The answer to the 21 and 23 spline stuff is on the Marlin website under t-cases...read.

"completely rebuilt" 22RE...and it'll fly...80 mph on the highway no problem w/ plenty of pedal left. My 85 will run circles around my 87...and twice on Sunday.

Again, 37s is TOO much tire on IFS w/ a stock drivetrain. And w/ no lockers or regearing...a crawler isn't much good either and certainly a waste of money IMO for what you want to do...it is just impractical. You'll get more places double locked on 33s than you ever will on 37s open w/ a crawler...you are just going to spin slowly.

 

Or you can buy a trailer and trailer the '86 behind your T-100.

 

Totally agree, but if I've learned one thing on here, people are gonna do what they wanna do, may as well give them the advice that gives them half a chance to make it work...

 

well ill run ifs till it craps the bed then if the future ill do a sas but in nh we go through mud and go down trails no rocks here so im in no rush.

and i have a trailer and the t100 would struggle with that load so i use a 05 siearra 2500HD to pull my toy but thats too much work so i would just rather drive it to the trails.

 

got 4:88 put in my rear...wait a minute ,don't like the way that sounded ..anyway with 33's and if you actually measure their a little under 33 and even more under 33 with low air pressure. It pulls great holds speed up most hills. Now i don't have to feather my clutch to take off. I got other problems but big smile on the gears. Thanks to you guys for reasurring my first instincts!!