What overall gear ratio do you like to run?

[Gravy]

I'm 153:1 with 39.5"s, 4.0 and 5 speed manual.

I hit most stuff in 2nd or 3rd in low low.
I feel for me it's a good split because 5th is only 30:1 and I can spin them or roll out of steep obstacles well,
so low low works great for most technical stuff.


4.01 first gear

2.72 front case

2.62 rear case

5.38 axles

If I had the perfect split it would be about the same but I would go either:
2:1 in the front case and 3:1 in the rear case
or 1.76 in the front and 3.2 in the rear.

It's imaginary though since that combo would cost a lot to make happen and be strong/ light enough for me.

 

[B2-Bomber]

i am assuming freeway speeds are an absolute pipe-dream in a rig with those specs?

*edit, i take that back. near 40" tires, and o/d could possibly do freeway speeds

i forgot because my rig has neither of those and it didn't cross my mind at first

 

[TJDukit]

I'm running 72:1 right now with 35's and a manual. It's actually a little fast for me sometimes in first gear. Mostly because of the lack of low end power with the 3.8L, sometimes it will bog down and die in 1st gear. When I move up to 37's I'd want 5.13's for crawling but 4.88's for highway. I'll probably end up doing 4.88's because I'll be at 87:1 crawl ratio and 65mph RPM will be just under 2500, and it is my DD afterall.

 

[Gravy]

i am assuming freeway speeds are an absolute pipe-dream in a rig with those specs?

*edit, i take that back. near 40" tires, and o/d could possibly do freeway speeds

i forgot because my rig has neither of those and it didn't cross my mind at first

It's not street legal but I've taken mine up to 75mph (with unbalanced bias ply tires and no sway bars it's not bad)
5.38's put my gearing just lower than stock. 5th is .78 so no RPM issues.

I keep looking for a set of Michelin XL 11-R16 (10.9" wide x 38.7" tall x 16" wheel) so I can plate my Jeep and drive it on the road.

If I can sell my 4runner I'd love to buy a set from this guy. (but he hasn't had any for a year!)
http://www.pirate4x4.com/forum/axles-tires-wheels/853931-brand-new-michelin-xl-11-r16-39-tall.html

 

[B2-Bomber]

those tires are everywhere. i heard without major siping they suck pretty good

 

[Gravy]

The ebay ones are NO SHIPPING. Plus shipping on them are dang near $300 from anywhere.
Worth it though.
and I don't have the cash for them unless my 4runner sells anyways.

One of my best friends ran them on his 77 f250 for 4 years with a rear spool. Load range E They wore like 1/4" in 4 years... and they are regroovable.
They are actually decent in the rocks at 0psi. When we went to Moab 4 years ago we pulled the valve stems completely and walked up Widowmaker on Metal Masher. (Keep in mind his rig was close to 6500lbs).
The sidewall are dang near 1" thick. You'd never need a spare. I wouldn't wheel with them... just drive them on the street.

 

[mbryson]

I'm running 38" Kevlar MTR, 4.56 gears in the diffs, 4:1 in the transfer case and a 700r4. It's plenty low on the trails. I think it spends a lot of time in 3rd in non-technical sections when using low range. I'm not sure what final "overall gear ratio" that equals out to, but I think I'd rather go to 4.88s in the diffs and maybe 3.2-3.4 in the low range. Not willing to spend the $ to do it, though.

 

[mombobuggy]

Tuff lookin rubi I especially like the intercooler nothing like boost, Love a set of those shoes for the S.D. neat.

 

[Gravy]

4.56x4x3.06 (1st in the 700r4) is 55.8
That's plenty low in an auto.

I feel like a good rule of thumb is 1/2 -5/8 of what you run in a manual is fine for an auto.

Marc you're fine on the freeway with that nice V8 power. But 4.88 would give you a little more pickup around town and you'd still be in a nice rpm range. If I recall you rarely if ever drive that thing further on the road than to Neilson's Frozen Custard.

after going to dual cases I can believe I'd never be happy with a single super low range (like 4:1) on a multiple use rig.

 

[B2-Bomber]

i could swear 700r4 was 3.06
First - 3.059:1
Second - 1.625:1
Third - 1.000:1
Fourth - 0.696:1
Reverse - 2.294:1

 

[Gravy]

It is. I wrote wrong.

 

[B2-Bomber]

btw i misunderstood you, when you said

I keep looking for a set of Michelin XL 11-R16

i thought you didn't know where to gey any. yeah the shipping will kill you

 

[mbryson]

4.56x4x3.06 (1st in the 700r4) is 55.8
That's plenty low in an auto.

I feel like a good rule of thumb is 1/2 -5/8 of what you run in a manual is fine for an auto.

Marc you're fine on the freeway with that nice V8 power. But 4.88 would give you a little more pickup around town and you'd still be in a nice rpm range. If I recall you rarely if ever drive that thing further on the road than to Neilson's Frozen Custard.

after going to dual cases I can believe I'd never be happy with a single super low range (like 4:1) on a multiple use rig.

It runs to get groceries occasionally but is a rare commuter (4-5 times per year) and an even more rare "driver". It's MUCH better with the 38s than the 40" Kevlars. That was part of the plan with moving to the smaller tire was to get a little more use out of it. I have been going to "square" it up (alignment wise) and drive it more, but just don't know that I'd drive it much more than I do now. It's still setup as a butch trail rig as far as that goes

 

[B2-Bomber]

after going to dual cases I can believe I'd never be happy with a single super low range (like 4:1) on a multiple use rig.

I agree, getting all of your gear reduction in one shot is crazy, like my buddies with short as hell diff gears. or the guys with 4:1 t-cases. it is either too tall, ot too short
that is why i opted for my sm465 transmission, that granny low first (and a reverse that matches it) is just like a 2:1 doubler. most transmissions are around 3:1 first gear.
so my 6.55:1 granny is like a 2.20:1 doubler on a 3:1 first gear.

i could toss a doubler onto my np205 and easily be in the mid-100s. with no real sacrifice on strength, and no major expense. but my v8 has enough power that i don't need to gear it like a 1.3L suzuki

 

[jeep-N-montero]

With a 2.74 first gear, 2.72:1 in the stock np242, and 4.56 gears running 35's the "calculator" only spits out a 34:1 crawl ratio. Not sure if that sounds right but with the v8 it all works well enough.

 

[Gravy]

With a 2.74 first gear, 2.72 to 1 in the 242, and 4.56 gears running 35's the "calculator" only spits out a 34:1 crawl ratio. Not sure if that sounds right but with the v8 it all works well enough.

That's right. And it's plenty fine for what you do with your rig.

The only drawback the 203 205 doubler (or my 231/300 doubler for that matter) has is that both cases are so close (in ratio) that it doesn't give you as many options as a better split.

Power isn't the only reason to gear so low, sometimes that lower speed gives you more precise control.

 

[B2-Bomber]

2.72 x 2.74 x 4.56 = 33.98 so yeah, sounds right

 

[cruiseroutfit]

With a 2.74 first gear, 2.72:1 in the stock np242, and 4.56 gears running 35's the "calculator" only spits out a 34:1 crawl ratio. Not sure if that sounds right but with the v8 it all works well enough.

2.74 x 2.72 x 4.56 = 33.98:1. Any calculator should have the same results plus or minus a few decimal points

 

[cruiseroutfit]

We all flocked to that arithmetic lol

 

[jeep-N-montero]

That's right. And it's plenty fine for what you do with your rig.

The only drawback the 203 205 doubler (or my 231/300 doubler for that matter) has is that both cases are so close (in ratio) that it doesn't give you as many options as a better split.

Power isn't the only reason to gear so low, sometimes that lower speed gives you more precise control.

I really wish I had a lower ratio in this heavy pig when coming down stuff, it would be very nice to not have the weight and torque overpowering the brakes all the time, sometimes I just to shift to neutral and the brakes are fine. But we are hoping our tax return will allow for a transfer case upgrade to make things safer.