scavenger45

Maybe this is on a different thread but cannot finbd it. I'm looking at a gearing calculator and it is showing with a 6.1 t case i can actually do better on the highway with 4.10 pinion gears on 35's than with 5.29. it still looks like i would have decent crawl speeds. so why does everyone recommend 5.29 or 4.88?

BigBluePile

iTrader: (3)

What's a 6.1 tcase?

scavenger45

a custom built transfer case with 6.1:1 gearing

scavenger45

i am simply asking why everyone recommends the 5.29 when the calculator shows 4.10 would give me a higher max speed in 2wd and still give me a good crawl in 4wd

nvtoyota

because everyone thinks that the bigger the number the better. this is one of those things many people just throw answers at without doing the math. build the truck you want

BigBluePile

iTrader: (3)

Lolz. Um.....right. 6.1 in the tcase right? Which will replace the 2.28 right? That's the LOW range gear, right? So, then yes, most likely 4.10s will be fine running that LOW range.

However, running 35's with 4.10's (assuming your small displacement motor) sucks cow sack. Which is why in HIGH gear people choose to run 4.88's, 5.29's or 5.71's. It's a duality thing. You can get a little extra gear reduction PLUS streetability.

dark_fairytales

I just ran some numbers using your 6.1 custom t-case. After doing the math I have determined that the OP must be confused about the relation of the gears in the t-case.

Too clarify:

22re produces 140ft/lb, 5th gear w56 tranny is .85:1, ring and pinion 4.1:1, and stock tire size 28". So we must calculate the force applied to the road at the outer diameter of the tire:
(140Ft/lb), multiplied by 5th gear (.85), multiplied by ring and pinion (4.1), divided by the radius of the tire.
-140x.85x4.1/ 14= 34.85ft/lb at the edge of the tire.

The same thing can be calculated for 5.29 gears
-140x.85x5.29/ 17.5= 35.79ft/lb at the edge of the tire.

Now assuming it is possible to change the 2wh to 6.1:1 we can run the numbers again.
-140x.85x6.1x4.1/ 17.5= 170.06ft/lb at the edge of the tire.
We can see that does not work, the rpm would be insane to produces that kind of torque to the road surface when the engine can only produce 140ft/lb max.

hopefully this helps some with the understanding of gear selection, if there are further question please ask.

scavenger45

maybe i am confused about how the transfer case works then? i was under the assumption in 2wd we would be in a higher gear.. (i.e 4:1 and only in 6:1 when in 4wd?) is this incorrect? also i am running a tacoma 3.4 which has substantially more more power than a 22re.. sorry didnt know engine made a difference with the gears. sorry I'm not very good at this stuff.. this is my first attempt at 4x4

WHEELER8688

you need to find out what the gearing in the trans case is in different gears and your other gear ratios if you dont know them, and with more power you dont have to run lower gears because the motor is able to pull better because of the increase in torque. when you find out the gearing use the formula dark_fairytales used to find out what gearing would be best for you. and an example of what a more powerful motor does to gearing I used what would be in an older Chevrolet pickup with a small block, lets say it puts out about 300Ft/lbs and has a 700R4 tranny, 3.73 gears and 31in tires,
300x.70x3.73/15.5=50.54Ft/lbs which is a good amount more than a stock Toyota and it has lower gears and bigger tires.
I did the math with my stock Toyota with 31s and it puts out 31.5ft/lbs
and thank you dark_fairytales for showing me that formula, Ive done used it to figure out a few cars already

BigBluePile

iTrader: (3)

Youre gonna need an adapter.

BigBluePile

iTrader: (3)

dropzone

iTrader: (6)

I am pretty sure that 6.1 T/C gears are only available for a Samurai.

All Toyota T/C gears sets currently available only affect low range. Your High Range will not be impacted by a swap and if you put in a sami case like the rock lobster kit..it will break

35's and 4.10's in 2WD high range will bring the suck as far as a DD on the street.

kawasakilewis

changing to a 6.1 will not affect you on the road unless you are in low range. hi range is a 1:1 ratio, and you cannot gear down your high range in your transfercase, i am slightly confused as to what you are meaning.

dark_fairytales

Its good to know the info. I provided has worked out for you WHEELER8688.

I ran the numbers again Scavenger with the new knowledge that you have a 3.4, and it turns out if you want your rig to drive like stock on the street or freeway, you will want to choose 4.88 ring and pinion gears.

Here is the math:
220ft/lb x .83 x 4.1 / 15= 49.91ft/lb of force to the road surface
220ft/lb x .83 x 4.88 / 17.5= 50.91ft/lb of force to the road surface.

Good luck, happy wheeling.

scavenger45

Thank you dark fairy tales i will put in the 4.88.

and to drop zone i am not sure if it will break or not but that is why i am trying it.. if it breaks i'll just go with a different transfer case when i fix. now that i know the formula i can mess around with a bunch of different things when/if it breaks anything