Well, I'm running 31x10.5's on my v6 with an auto tranny, and stock gears are 4.56's, and I'm getting 17-18mph city, 21 highway at 30psi

 

A "Totally stock" V6 auto with 31's (per your signature) would have 4.88.

The manual transmission trucks that came with 31's have 4.56

 

3:73? is your code G304 or G302? Have never heard of such gears, must be a total DOG

 

Alot of neat info, thanks. I guess I will double check the existing gears and try out the tires I have with the new motor (22RE rebuild) and then put 31's on it when I buy new tires, we'll see how it goes.

 

All the gear and tire recommendations above are correct.

I got bored one day in a really long meeting and did some calculations:

using y = mx + b, where y = your tire diameter and x = your gear ratios you first solve for m, which is slope.

Just take y2 - y1 / x2 - x1. for a manual transmission use 31"-29" / 4.56 - 4.10 OR for an automatic use 31"-29" / 4.88 - 4.30 which gives you 4.347826 and 3.448276 respectively.

manual tranny, m = 4.347826
auto tranny, m = 3.448276


Next solve for b, which is the constant.
Y = mx + b or
29 = 4.347826(4.10) + b
b = 11.17391 (manual tranny)

or b = 14.17241 (auto tranny)

So then if you have a manual tranny truck and want to know what tire goes with what gear just solve for y (tire diameter) using x (gear ratio) using:

y = 4.347826(x) + 11.17391

For example, y = 4.347826(x) + 11.17391 where x = 5.71 then y = 36"

What this equation does is helps you match your gear and tire diameter selections to make your engine perform in relatively the same power band or curve as it does with factory gears and tires, if that is important.


I just thought it was interesting to verify mathematically the good advice folks give here on gear and tire sizes. After I figured out which gear sets to start with the rest was pretty easy. We all had this stuff in 8th grade.

And that's all the algebra i ever learned!

 

http://www.discounttire.com/dtcs/infoTireMath.dos

 

http://www.grimmjeeper.com/gears.html

http://www.4lo.com/4LoCalc.htm

 

When i was building my truck i had the 3.0/Auto/33s/4.10s. It ROYALLY sucked. I ran it like this for about 6 months until my stock rear-end started going out b/c the shop that installed my detroit didnt set up the gears correctly.

From there I sent the 3rd out to AZ for Zuk to put 5.29s in it. I put such a low gear in there b/c i needed it to run OD in the tranny. (~16 mpg)

Jump forward from july 2007 to june 2008.

This June we put a R150F from a 91 p/u in my 4runner. Now my configuration is 3.0/R150F/5.29s/33s. It is quite quick, but my top end suffers greatly. i run 60-63mph on the interstate at ~3000 RPM. I am now getting a solid 20.5MPG.

It may be overgeared but i ABSOLUTELY love it.

 

buy the way.. where can we buy these gears to switch? I think new tires may be coming sooner than I thought. I have a couple of bent rims, thinking about buying new steel rims from toyota, having them chromed like the chrome option in 88 (the alloys were not an option for the deluxe, plus they are $370 a piece) and maybe using Bridestone dueler AT's in 31X10.5 15LT like I had on my 93 SR5 before. Those tires worked well in the mud I had to work in doing radio station proofs. 3rd gear, 3000 rpm with the 3VZE worked well. I haven't had the 22RE out int the mud so I will have to learn it.

 

Pick up an off road mag and you will find a lot of places to get everything from a set of gears to a completly built 3rd.

 

Performance Offroad Center (PORC) and Randy's Ring and Pinion seem to have the best prices. Marlin Crawler, Trail-Gear, and others have assembled third members too.

Now would be the time to do a locker or two while you're at it. When I was last looking, an assembled third with a locker was about the same price as buying all the parts and having them professionally installed, and obviously a lot less trouble.

 

Uhmm.. I have not seen any 3rd gen toyota trucks that ever came with any R&P smaller then a 4.10 If you do have 3.73 gears its not stock.


4.88 gears on the auto didnt come out till around 92-93 IIRC.

 

Because that's when they started putting 31's on from the factory ...

 

I have 42" with 5.29 gears and an auto tranny. Its not a race truck but it does ok.

 

Dude...I had a 3.8 GPA and was a math major. You lost me... wow.

 

what gears would be good for 38 15.50s on my 83 pick up

 

5.71 ... actually, I would suggest 6.14's in a Ford 9" or Dana 60 if you really wheel hard enough to truly need 38's...

 

Are you daily driving the vehicle? Trailer queen?

These factors can make a big difference in what gears will be best, depending how you use the truck. Another big factor is the gearing in your transfer case? stock? dual cases? 4.7 case?

 

Very confused here.......I have a '93 v6/5spd with 4:10's, I put 31" BFG's on it and I can stay in 5th uphill and even accelerate on longer hills plus the speedo is dead on with no modifications.
Its no rocket but it keeps up with traffic just fine and yes I have driven modified trucks so I know what proper gearing and acceleration feels like.
Considering that the 3.0 is no beast I can't see that 4:56's would be better.

 

I've got 33's on my p/u with 4.10's, it goes o.k., and handles hills fine. I will also say...I have had 4runners before Auto, and 4.56 gears, from the factory, and that with 32's didnt go as good as the p/u with 33's and 4.10's.
I also have a 93 auto with 4.88's and 31's, and that is just about same takeoff speed as the p/u.