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+--- Thread: Gearing and Crawl Ratio's (/thread-653.html)
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Gearing and Crawl Ratio's - johnpaulgolf - 05-13-2008
Ok I've been doing some searching for the right set up for better "crawling"
I've been getting with Chuck about buying his axle's(which I will when he finds new ones) and kickin around new gears ect.
This is some info I've recently learned.
I now have a T-Shift D20 and a RAT 3 speed and 3.50 gears w/34"tires
Chuck has a NP435 with a J-Shift D20 and 4.56 gears w/ 38.5"tires
This is a PM I sent Chuck talking about my situation
I did some research...here is the numbers
RAT 3 speed 1st=3.41 2nd=1.86 3rd 1.00
NP435 4spd 1st=6.69 2nd=3.34 3rd 1.79 4th=1.00
T-shift D20 low=2.46
J-shift D20 low=2.34
so mine now = 29 to 1
my D20 w/NP435= 57 to 1 (real soon)ASAP
mine w/ 4.88 gears = 40 to 1
mine with your axles = 38 to 1
my D20 + NP435 with your axles = 75 to 1 (future mods)
yours now = 71 to 1
so you are the man again the cheapest fastest way to crawl will be the NP435 hands down.
thanks bro
Gearing and Crawl Ratio's - chuzie - 05-13-2008
Do you already have a 235 or are purchasing one?
Gearing and Crawl Ratio's - johnpaulgolf - 05-13-2008
I need to find a NP 435 not a 235...whats up stranger?
Gearing and Crawl Ratio's - 66gasgrill - 05-14-2008
If you run what I am you'll end up with 80 to one well 80.3. Np 435- 4.88 gears and 2.46 Tshift t-case. Don't forget to factor in you tire size also. This set up with 37's would be alot different than this set up with say 44's.
Gearing and Crawl Ratio's - johnpaulgolf - 05-14-2008
66gasgrill Wrote:If you run what I am you'll end up with 80 to one well 80.3. Np 435- 4.88 gears and 2.46 Tshift t-case. Don't forget to factor in you tire size also. This set up with 37's would be alot different than this set up with say 44's.
Thats sweet "gas" 80 to 1 is sick slow crawling.
How do the tire sizes affect the ratio's?
How do I put that(tire size) info in the equation?
Gearing and Crawl Ratio's - 66gasgrill - 05-15-2008
Tire size doesn't change your actual crawl ratio. It changes your effective ratio (what it feel like) if that makes sense.
Say your setup at 80:1 crawl. you will still have an 80:1 crawl ratio whether your running 31's or 44's but they won't feel the same. See what I mean kinda?
Check this site, maybe it explains it a little better. If not it still has some good info. HTH.
http://www.4lo.com/calc/geartable.htm
Gearing and Crawl Ratio's - High Pressure - 05-15-2008
66gasgrill Wrote:Tire size doesn't change your actual crawl ratio. It changes your effective ratio (what it feel like) if that makes sense.
Say your setup at 80:1 crawl. you will still have an 80:1 crawl ratio whether your running 31's or 44's but they won't feel the same. See what I mean kinda?
Check this site, maybe it explains it a little better. If not it still has some good info. HTH.
http://www.4lo.com/calc/geartable.htm
Don't know a great deal about this crawling stuff but that was well said..:xyxthumbs:
Gearing and Crawl Ratio's - SC74 - 05-15-2008
I always think of a 18 spd. bicycle when I think about gearing in a truck. That way you've got your 3 main gears (tranny, t-case, axles) plus 6 sub-gears (trans. gears, t-case high/low) on each main gear.
As for tire size, it takes more to turn the bigger meat. Just like on a bicycle, it takes more effort to turn a larger tire (especially off of the start) than it does a smaller one.
Gearing and Crawl Ratio's - broncomatt - 05-15-2008
JP, I would go with lower axle gears. My rule has always been with 33" = 410 or lower, 35"=456 or lower and 38" and up 513 gears. I would not rely on trans and t-case just to make the ratio.
Just my 2c.
Broncomatt
Gearing and Crawl Ratio's - bucketobolts - 05-15-2008
I started out with the NP435, a T shift case, 4.56's, and 35" tires. With the original 302, I could let the engine idle(800 rpm) in low gear low range, and it was hard to stall the engine with manual brakes. I had several stumps in the yard I used to play on by letting it idle up and across them.