Topic: Gear ratios?

[skipnrocks]

Alright Everyone I am just wanting to know your crawl ratio at the wheels and weather its perfect/insufficient/too much...  Please include where your gearing is at also if you know...

Tranny =6.58:1
T-case =10.34:1
Axle     =4.10:1

Total    = 278:1


I dont know how it works cause I havent finnished my rig yet...

[jimbo74]

what tranny do you have?

my crawl ratio is like less than 40:1 lol

[jimbo74]

what tranny and tcase do you have? where did you get those numbers from?

my tranny is like 3.x and tcase is 2.28





36.74 crawl ratio

g52 trans, stock tcase, 4.10s

[Duffil]

he's running like an SM420 and an Atlas, IIRC.

that should be way fine...dual ultimate with 5.29s is 223:1.

[skipnrocks [OP]]

I have an atlas 4speed, and my low low is just over 10to 1
and my sm465 has a granny low of almost 7 to on....

I just did a general search to find the exact ratios in my tranny, and since i configed my t case and axles I already knew..  


How do you guys like your gear ratios, are they too low, too high, or perfect?

[jimbo74]

I have an atlas 4speed, and my low low is just over 10to 1
and my sm465 has a granny low of almost 7 to on....

I just did a general search to find the exact ratios in my tranny, and since i configed my t case and axles I already knew..  


How do you guys like your gear ratios, are they too low, too high, or perfect?

i dont know how my truck works yet, have never driven it

[skipnrocks [OP]]

i dont know how my truck works yet, have never driven it

LOL me either but Im gettin close,  should be able to test drive over christmas break.

[Duffil]

I am at 99.69:1 (g series, stock duals and 4.88s) and I think by itself, 2x low is too low sometimes...I roll around in 2nd a lot, I think 4.7s in the rear case would help.  Overall, i give it an 8 out of 10.

of course when I really need it, it's not low enough...

[germ]

I'm currently running around 100:1 with W56a tranny, and dual cases with 2.28 low and 4.88 axle gears. It works very well, and I'm happy with the set up. I am however needing to do some tranny work, and since I'll have it all apart, I'm going to put a Marlin 4.7 gearset in the forward T-case. The math says I'll have about 256:1 with that set up.

Erik

[germ]

Tranny =6.58:1
T-case =10.34:1
Axle     =4.10:1

Total    = 278:1

The only disadvantage I see to your set-up is that when you go into "low" your extremley low. The advantage to having the dual cases is that you can select how low to go. I know your trying to stuff all this in a Jeep, so space is at a premium. I used to have a Chevy Blazer with the SM420, and that 1st gear is a crawler. Fortunatly 2nd gear is low enough to start out in, so you'll have some flexibilty with that.

I think you'll be very happy with your set-up, and you'll get around the disadvantages, and excell with the advantages.

Erik

[skipnrocks [OP]]

The only disadvantage I see to your set-up is that when you go into "low" your extremley low. The advantage to having the dual cases is that you can select how low to go. I know your trying to stuff all this in a Jeep, so space is at a premium. I used to have a Chevy Blazer with the SM420, and that 1st gear is a crawler. Fortunatly 2nd gear is low enough to start out in, so you'll have some flexibilty with that.

I think you'll be very happy with your set-up, and you'll get around the disadvantages, and excell with the advantages.

Erik

I actually have atlas4 speed so my gear ratios in the t-case are

1:1, 2.72:1, 3.8:1, & 10.34:1

So I can chose between
 Overall
27:1
74:1
103:1
and 278:1

I think this range would be comparabe to duals?  I actually was going to do duals, but not having a t-case to start with would have made it too expensive I think? (I got a deal on my atlas) And I couldnt afford the driveshafts becoming shorter with my wheelbase, with the atlas only being 15 or so inches thick it actually lengthened the rear and front d-shafts and their almost interchangable so One spare will work front or rear...

But when I see people on here puting tripple cases in with ratios in the 1---s  I was real curious what other people are running and how they like it....  I have not spent much time in the rocks but thats what I have been building my rig to handle...


The sm420 isnt doesnt have od? does it?    I know it has an even lower granny than my 465

[bigarms23]

between the gears(513s) stock tranny(r150) and dual cases(2.28&5.0) my crawl ratio is around 250to1

[skipnrocks [OP]]

between the gears(513s) stock tranny(r150) and dual cases(2.28&5.0) my crawl ratio is around 250to1

What does it mean between the gears?

[bigarms23]

sorry about that i was referring to the whole thing not just gears

[Doof]

how do you find your crawl ratio? do you get the numers in the first post and multiply them all together or what?

i gave you +1 since your jeep is pretty bling

[Duffil]

how do you find your crawl ratio? do you get the numers in the first post and multiply them all together or what?

i gave you +1 since your jeep is pretty bling

trans gears X tcase X axle gears

http://www.marlincrawler.com/java/getratio_calc.html

[Doof]

that thing is sick.... thanks... i need to now find the right numbers to plug in there

[Duffil]

that thing is sick.... thanks... i need to now find the right numbers to plug in there

search on the MC trans page...and your tcase is 2.28.

[Doof]

i take it i leave the crawl box ratio blank?

[Duffil]

i take it i leave the crawl box ratio blank?

yes... you should be at about 36.73:1 if you have 4.10s still.

edit: you should have a w series trans...36.92:1

[Doof]

well i put my numbers in and it didnt spit anything back out...and yea im rollin stock open front and rear and when im in low 4 i still move way to fast

can you crunch the numbers for 5.29s for me real quick?

[Duffil]

3.95x2.28x5.29=46.74:1

[Doof]

better...thanks

when i get my duels it will be a lot better... stock front case with the 4.7 in the rear or visa versa not sure... cant wait though

[skipnrocks [OP]]

sorry about that i was referring to the whole thing not just gears

Oh LOL thanks man I was a bit stumped over that for a while, I must have read it 10 times before I gave up.... 

better...thanks

when i get my duels it will be a lot better... stock front case with the 4.7 in the rear or visa versa not sure... cant wait though

Thanks man for the point,  I suppose that makes up for the point you took away yesterday for jackin your thread  (i didnt know you can give those points?) ...  LOL


Yep you take your first transmission gear and your t-case low and multiply them, and then you take that number and multiply it by your axle gear ratio.....  ie....  tranny X t-case X axle = crawl....
There are some fancy calculators that factor in tire size also but thats not really nessisary here...

[sinbob]

w56 tranny..........3.95
axels...................5.29
xfer.....................2.28 =  47.64
dual xfer...............2.28 =  108.62

It is ok but I would like to get it lower.  That is why I will probly put 4.7 gears is the rear xfer.  Which would then take me to 223.91. 

[79coyotefrg]

3.93  tranny
2.28x2.28 dual case
4.37 gears  for now

89:1  i like it,  sometimes  too low for muddin

[KDC]

Tranny............3.93
Crawl Box.........2.28
T-Case............2.28
Diff.................4.88
Crawl Ratios
Double Low.......99.69:1
Single Low........43.7:1

After a trip to Moab on this set-up, I'm gonna put 4.70 gears in the rear case because there were a couple times that I wish I was lower.  This would put me at 205.5:1 with the options of 90.1:1 or 43.7:1

I think your gearing is perfect, skipnrocks.  The 74:1 is good for easy-moderate trails or sections of trails, while on harder trails and obstacles, the 103:1 is great for ledges, steep climbs, rock gardens and such.  Then when you absolutely need perfect tire placement and incredibly slow speeds such as straddleing a crevice, while trying to climb an off-camber rock face like this:

or this:

the 278:1 will come in very handy.

[skipnrocks [OP]]

Thats some intense crawlin!!   Is there anyone that has some more extreme ratios, do you ever use the really really low?

I know this is off topic but what keeps the drivers tire on the jeep from droping?  Is it the pitch of the climb, torque of the drive line, suspension or what? 

[KDC]

Thats some intense crawlin!!   Is there anyone that has some more extreme ratios, do you ever use the really really low?

I know this is off topic but what keeps the drivers tire on the jeep from droping?  Is it the pitch of the climb, torque of the drive line, suspension or what? 

It's the pitch of the climb.  About 10 feet after the first picture is where the second picture was taken, it's just the angle of the picture doesn't show the steepness well.  In fact, the driver front tire of the truggy is about where the rear diff is of the Jeep.

[bigarms23]

my old 85 4runner which i miss had the low 515tranny gear with triple tcases and all three cases had 4.7 so if someone could do the math that would be good