Crawl Ratio's

[CntStpTheStnk06]

so im trying to decide exactly how to go about slowing my jeep down on the trail. The obvious is gearing, but i currently love my highway speeds and would love to keep somewhat good gas millage and high speeds to drive back and forth to VT. So my current setup is......

98 xj 6 cylinder
5 speed
d30/8.25 3.07 gear

so off road im way to fast to crawl anything and find myself using the clutch a bit to slow her down. i have been reading up on these Tera Low kits that offer the 4:1 reduction....... I plan on gearing down the road and think that the tera low and gearing could be a perfect couple for a nice and slow crawl ratio.( correct me if wrong)

Im currently running 33's but plan to move on to 35's within the year. i am thinking that the tera low may allow me to gear to 4.56 eventually and run 35's . so that way my 2wd speed would not be too bad but my 4low would creep right along.

i would love to hear opinions, suggestions, even the insults

[konastinky1234]

use this:

http://www.grimmjeeper.com/gears.html

compare your standard t case ratio to what it would be with the tera.

you should have:
ax-15 (3.83:1 first gear)
np231 (standard, 2.72:1 low range)
no underdrive
enter tire size

my final ratio is 52.9 to give some perspective. if i were to swap in 4:1 over 2.72:1 on my t case my ratio would rocket up from 52.9 to 92ish. that is a HUGE reduction. you know my jeep so there is some perspective. when i get my 4.88s in i will achieve a 62:1 final ratio.

[Hydra]

For the price of the TeraLow you could buy another 231 or 300, a doubler kit and shaft lengthening/shortening

[clean4drxj]

For the price of the TeraLow you could buy another 231 or 300, a doubler kit and shaft lengthening/shortening

this, and or get a 241 rocktrac...
Even if you put the install the tera kit you still have the weak chain.

[CntStpTheStnk06]

ya im wondering if i should just screw my highway gear...... and build for the crawl....... but just for kicks has anyone used the tera low or a different t case instead of gears?

[Hydra]

Well that's the beauty of the crawlbox, you retain your current 2wd high, and then in addition have 2the low, 4 high, 4 low, and low doubled.

Your only issue with a doubler will be driveshaft length

[justtorchit]

i personally think that people should gear the axles before investing in a T-case setup.

you have 3.07's and 33's? And actually enjoy that on the hiway??? i curse the fuckin world everytime i am cruising at 50 on a senic road and the engine bogs down and has to downshift.
id say just go strait to 4.56's, id personally rather go 65 on the hiway and know that i can maintain that speed going up the next incline.

another thing people forget about when doing doublers and 4 to 1 kits, is that you put twice the amount of tourque on the driveshafts in 4 lo. Without changing the gears in the axles too, it makes for shattering surprise when the tires dont wana spin but the driveshaft does because its has twice the torque.....
Kappy tried this experiment once. 36's with 4.10 gears, and the tereflex box..... driveshaft shattered within the first 5 minutes of the trail.

now if ya have beefy driveshafts and actually enjoy being underpwered, sure go for it.
i just think doing a t-case before the axle gears is ass backwards.

[CntStpTheStnk06]

Ya it's awesome on the highway I did not believe it either but it does 70 in 5th at 2000 rpm I did not expect it to drive well on the highway ...... It just kinda happened and I would love to keep that but that was what I was wondering was how the rest of the drivetrain would Handel it . And ya seems like axels to start........

[customcreationsllc]

for the price of a tera low and a SYE you can almost buy an Atlas

Cheapest best way out buy a D300 $200 flip shifters $150 and a 4:1 kit $600.
No need to buy a SYE (use a 231 CV yoke on a 300)

next cheap option if you want even lower is to do the 231 crawl box to a D300.

best is still an atlas.

[CntStpTheStnk06]

Ya buti would still run into issues with blowing up drive shafts or other axel parts ect.... Seems like something I am definitly interested in for down the road ....... But it sounds like I should have my axels set up befor I pursue 4:1

[ct67_72]

Ya it's awesome on the highway I did not believe it either but it does 70 in 5th at 2000 rpm I did not expect it to drive well on the highway ...... It just kinda happened and I would love to keep that but that was what I was wondering was how the rest of the drivetrain would Handel it . And ya seems like axels to start........

Is this taking onto account the difference in tire size? With a 33 your speedo will be 5mph low. So if it shows 70 your really going 75 at 2000.

[customcreationsllc]

Ya buti would still run into issues with blowing up drive shafts or other axel parts ect.... Seems like something I am definitly interested in for down the road ....... But it sounds like I should have my axels set up befor I pursue 4:1

Makes absolutly no difference in your axle strength.

Torque is reverse from the wheels back you can only apply as much as you can react changing the gearing does nothing for your traction so your axle shafts will still be exactly the same strength.

If you are not breaking stuff now you will not be breaking stuff with a lower range.
Only difference with lower range you don't have to step on the gas as much to break when your tires are bound. even with 2.72 and 3.07 you probably have enough torque to snap an axle when it is bound anyways.

With faster gears your drive shaft back will se more torque but 3.07 to 4.56
so your drive shaft back will see 30% more torque.


Basically gear axles for the road gear the T-case low range for crawling.


Make sense?

[CntStpTheStnk06]

Is this taking onto account the difference in tire size? With a 33 your speedo will be 5mph low. So if it shows 70 your really going 75 at 2000.

and she accelerates awesome up the hills i dont know how.......

Makes absolutly no difference in your axle strength.

Torque is reverse from the wheels back you can only apply as much as you can react changing the gearing does nothing for your traction so your axle shafts will still be exactly the same strength.

If you are not breaking stuff now you will not be breaking stuff with a lower range.
Only difference with lower range you don't have to step on the gas as much to break when your tires are bound. even with 2.72 and 3.07 you probably have enough torque to snap an axle when it is bound anyways.

With faster gears your drive shaft back will se more torque but 3.07 to 4.56
so your drive shaft back will see 30% more torque.


Basically gear axles for the road gear the T-case low range for crawling.


Make sense?

ya but what about what justtorchit said about double the stress on drive train ect...... do i lesson the stress on the drivetrain by gearing the axels. I mean lets face it with lockers your stressing the axels and drivetrain to a certain extent any way but will the tcase stress it more?

[customcreationsllc]

Essentially the axles just lower/raise your first gear and top gear.
Anything in between will not matter what axle gear you have you just might be in a different gear.
So gear low enough to start and high enough to cruise down the highway.
Most offroad guys bias on the slow side.

Yes lower axles will lower the torque the drive shaft will see by the difference in the ratio. so 30% lower 30% less torque on the drive shafts.
Thats why I run 5.38s and let the engine scream.

so getting into torque.
Your axles can will only see more torque if you change your traction tire diameter or weight, what it takes to make the jeep move. not ratios.
you put a jeep on the lift and spin the tires how much torque do you have, zero. You need to react the torque to create it
Either your jeep is going to move forward or the tires are going to spin only if it is completely bound up will it make a difference.
At 50:1 100ftlbs=5000ftlbs which will even break 35spline chrome molys shafts so stock gearing has enough to break an axle lowering the gears will not cause you to break more just make the engine not work as hard to break the axle say you have 100:1 your engine only needs 50ftlbs to produce 5000ftlbs instead of 100ftlbs at the engine.

Where ever the your gear reduction is everything before will see less torque.
So if it is all in your tcase your trans/engine will see less torque
If the gearing is in the axles your drive shaft t-case trans engine see less torque.
but you can still only produce torque until the jeep moves or the tire slip.
If your not breaking it now lower t-case will not change anything.

usually you want the lowest gearing at the end so in your axles less the strain on the rest of the parts but you need to gear to drive on the road too.

I think I might be making you more confused hard to explain on paper.

1310 joints are pretty strong 1350 are only like 20% stronger. google the ratings.
Your drive shaft should be fine the other guy probably had other issues like high angles or crappy joints.
joints get weaker the greater the angle.



So the question is; do you break axles drive shafts now? do you ever get the tires so stuck you cannot get the engine to break them free? If no then you will not see any difference going with a lower T-case.

if yes we can talk further.

[CntStpTheStnk06]

ya it is hard to predict as i havent made any modifications to the axels yet. lockers ect. I plan on locking front and rear and im waiting to get gears in at the same time..... but i think im just going to start with gearing the axels