crawl ratio?

[92chevyz71]

hey what is crawl ratio and how is it calculated? i have a 700r4 to np241...whats my crawl ratio?

[SanDiegoCJ]

700R4 = 3.06 1st gear
NP241 = 2.72 low range
Axle ratio = ?????????? (You didn't state yours)

Multiply those 3 numbers.

[92chevyz71]

i have 3.73s...but what is the crawl ratio? is there like a definition or somthing?

[Chevyboy51]

crawl ratio is your total gear reduction in low gear yours would be 31to1. so for each revolution of the tires your motor makes 31 revolutions

[rockcrawlinredneck]

Originally Posted by Chevyboy51

so for each revolution of the tires your motor makes 31 revolutions

That's not true. If that were true then your tire size would have to be calculated in there somehow.

Kevin

[Tim84K10]

Originally Posted by rockcrawlinredneck

That's not true. If that were true then your tire size would have to be calculated in there somehow.

Kevin

That's not true. A revolution of the tire is a revolution...it doesn't matter how big or small the tire is.

[Dan Dibble]

Use this

http://www.dfw-tx4wd.org/gears.html

Good luck,

Dan

[blackrider]

now if you want rpm at a certain speed you do this

336 x ring&pinion x mph divided by your accual tire size equals rpm

336x[3.73x65]
-------- =rpm in this case 2670.92 rpm
30.5

this thing does'nt the space bar

[rockcrawlinredneck]

Originally Posted by Tim84K10

That's not true. A revolution of the tire is a revolution...it doesn't matter how big or small the tire is.

So your telling me that if there were two trucks will all the same gearing but one had a 30-9.50-15 and the other had a 44 that one revolution of each tire would travel the same distance? Why then do all of our speedomeders become inaccurate when we put smaller or larger than stock tires on our trucks?

Kevin

[bbagwell]

You are correct they wouldn't go the same distance. However they would both still have the same crawl ratio. As sated above it you have a crawl ratio of 32:1 then 32 revolutions of the motor equals one turn of the tire. So if you had 44" tires you would go farther than if you had 31" tires, but your crawl ratio is unchanged.

[Tim84K10]

Originally Posted by rockcrawlinredneck

So your telling me that if there were two trucks will all the same gearing but one had a 30-9.50-15 and the other had a 44 that one revolution of each tire would travel the same distance? Why then do all of our speedomeders become inaccurate when we put smaller or larger than stock tires on our trucks?

Kevin

No, I am not saying defy the laws of geometry regarding the circumferance of a circle.

I'm simply saying that for the purposes of this math equation, tire size is not a factor so the the end result is a ratio of x revolutions of engine to 1 revolution of a tire. Common sense, good judgement, and simple geometry takes it from there.