crawl ratio questions

99ncxj

99ncxj

Well-Known Member
Joined
Sep 23, 2006
Location
Aliso Viejo, CA
This isn't going to happen anytime in the real near future, but I do have some of the parts for a crawl box sitting on the shelf so I'm trying to figure out what to plan for.

I'm considering either going with a 4:1 in my D300 or building a 231 crawl box to go infront of the stock 300.

For anyone not familiar with my setup, here are my specs.

Jeep 4.0 (stock)
AW4 tranny
D300
4.11 gears in toyota axles.
39.5" tires


All of these numbers are already doubled to take into account the auto tranny/TC.

As of now my final crawl ratio in low range is 60.08 (feels more like high range in a stock truck)

If I do a 4:1 in the 300 my final ratio would be 92.06

If i leave the 300 stock and build a 231 crawl box my ratio would be 163.4 in low/low

And to get really low, I could do the crawl box and the 4:1 which would put me at 250.42 in low/low

With the typical trails we do (uwharrie, mtn city, harlan,) what would be "good enough" for a final ratio in everyones opinion? I'm not even considering regearing the axles because the cost for FJ80 gears is rediculous.
 
Justin, I would do the 4:1 in the D300. I did the 4.7:1 in my single case and love it. If you figure out that you need even lower gearing, then you could add the crawl box. For now, I think youll be happy with just the 4:1
 
It's definitely a subjective thing, but.......

I had 200:1 in The Krawler with the 4 cylinder motor and 42" TSLs. I liked it! My previous rig topped out at 75:1 and I was never happy with that for serious rock hopping. I usually ran in 120:1 in The Krawler running trails at Uwharrie, Mt City, etc. I just used 200:1 for obstacles sometimes.

My current rig, Great White, has a final crawl ratio of 63:1 with 35" tires. That's OK for what I use it for (no serious rock crawling, basic trail riding) while still allowing me to creep over some of the harder stuff. If I was going to tackle Armor All or Pull Cable type of stuff I would like to have at least double that for the way I like to drive.

Again, it's subjective and depends on the way you like to drive. If you like to hit it, you don't need as low a crawl ratio. If you like to let the tires slowly eat at the obstacle working back and forth for grip on a line then you probably can't get low enough.

Bottom line for me, 4.0L with auto and 39.5" tires = 100:1 range.
 
Totally subjective. I've had 200:1 or better in my last rig which was nice for getting positioned on an obstacle, but that is about it. The current one is 83:1 on 36's and works great, now whether that changes when I step up to a 39 we will have to see. I still think anything over 100:1 is overkill for general trail riding. Its the southeast, you won't crawl much unless we're in a drought.
 
I would go with the doubler just to have a few more gearing options. In my opinion high range is too high for running around from trail to trail, and 4:1 is too low. Its nice to keep that stock low range when going from obstacle to obstacle.
 
I'd do the 4:1 since the D300 is already in there. No other mods would be needed. With the auto you don't have to worry about gear selection as much. Just pop out of 1st/2nd and let the trans shift...

I was wheeling 700r4/D300(4:1)/4.56s/38s and as soon as I got off an obstacle it generally was in 3rd or OD pretty quick.. Just don't let the gear noise scare you.. (I think the 231 planitaries would be louder anyway... )
 
StretchASU said:
Totally subjective. I still think anything over 100:1 is overkill for general trail riding. Its the southeast, you won't crawl much unless we're in a drought.
Click to expand...

I disagree, but like we said, it is subjective and depends on driving style, rig, tires, testosterone, etc.
 
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