Crawl ratio question

[K85 Octane]

Yep
I was eyeballing that LS/4L80 combo as well until I learned of the 1st gear.
I like my 700/241, which would be similar to a 4L60/241 ratio. Can't do that, would rather upgrade.
Going to a 6L80 gives me an even deeper 1st gear than the 700.

 

[skunked]

I have always believed in gearing instead of power. I have had several Toyota buggies I have wheeled in the past. although I have sold or traded all those off and right now every buggy is running a V6. I have never had a V8 buggy but have wanted one. I bet the BBC is a good crawler since it makes its torque lower in the power band.

Yep, the low flat torque curve allows the truck to idle through the rocks and most obstacles.

 

[Tnsejed]

Everybody else touched on all of it except for one thing, how you drive it, and your converter.

I run 4l80e (which as was said has a high first gear) and 4.33:1 tcase with 5.13 in the axle on 42's. TCSperformance converter.

The torque multiplication doesn't really effect the crawl ratio. You utilize that combined with the brakes to get a slower controlled wheel speed. All depending on your torque converter and how it acts. I use both feet to crawl and modulate my wheel speed with the brake pedal. By doing this you can get a really slow wheel speed, while the rpm is closer to stall speed, with increased torque output.

 

[skunked]

Everybody else touched on all of it except for one thing, how you drive it, and your converter.

I run 4l80e (which as was said has a high first gear) and 4.33:1 tcase with 5.13 in the axle on 42's. TCSperformance converter.

The torque multiplication doesn't really effect the crawl ratio. You utilize that combined with the brakes to get a slower controlled wheel speed. All depending on your torque converter and how it acts. I use both feet to crawl and modulate my wheel speed with the brake pedal. By doing this you can get a really slow wheel speed, while the rpm is closer to stall speed, with increased torque output.

I don’t know what torque converter my transmission guy sold me but he’s a rock crawler himself. I also two pedal on some obstacles for better control or to avoid the jerking back and forth of the drivetrain.

 

[ZooMad75]

the 241 planetary is 2.72 and I’ve never felt the need to have anything geared lower than my current configuration. But I also have BBC torque feeding the drivetrain, not a 4 banger bouncing off the rev limiter.

I get it now. I didn't think about a magnum or nwf box with the 241 planetary gearset. duh...

 

[sweetk30]

if i was to buy / build another doubler i would NOT do another 203/205 now we have good combo units like ORD magnum box setup . this gets you a good all around 3 speed beefy box setup .

 

[mrk5]

I have a 4l80e/Magnum 205/5.13 axles which I think equates to 67.8; also with a 454. I can't imagine wanting anything lower for gearing. Matter of fact, I've been thinking hard about dropping back to 4.56 or even 4.10 in the axles. If the gearing was any lower, I think it would be really hard to stop the truck in some instances.

I have a stand alone controller for the 4l80e and on the trail I run it in manual mode. I run the trans in 2nd gear most of the time because it's plenty low enough and also allows the torque converter to lock up.

 

[fourwheelerjeff]

kinda off the subject of crawl ratio but I have a TJ with a 2.5 4 banger; 5 speed; TeraLow 4:1 and 4.88 in the axles. My dad has a CJ5 Jeep but it is completely stock. He had never been wheeling; so I invited him on a wheeling trip where I let him use the TJ and I used one of my Toyota buggies. the TJ has air lockers front and rear. I kept telling him all day Saturday to engage the front locker. he would tell me; "man this thing is amazing with the low gear and the rear locked, I don't need it'. well Sunday we went back out for a while and later he told me "I locked the front end today and it made a big difference over yesterday. I felt like I had more control with the front locked and pulling also".

he griped about how tall it was and now he has gotten older. I have thought about trying to find him a TJ and put a 2" lift and some 31's on it for him to have to putt putt around town and out to the farm in.

 

[mrk5]

I had long questioned the need for a Doubler or Magnum. After doing some wheeling with the Magnum, I'm truly amazed at the difference. Now the game I play is if the trail is a 2 locker, 1 locker, or no locker rating. A lot of trails I do now with the Magnum are "no locker" trails.

 

[Bent77]

kinda off the subject of crawl ratio but I have a TJ with a 2.5 4 banger; 5 speed; TeraLow 4:1 and 4.88 in the axles. My dad has a CJ5 Jeep but it is completely stock. He had never been wheeling; so I invited him on a wheeling trip where I let him use the TJ and I used one of my Toyota buggies. the TJ has air lockers front and rear. I kept telling him all day Saturday to engage the front locker. he would tell me; "man this thing is amazing with the low gear and the rear locked, I don't need it'. well Sunday we went back out for a while and later he told me "I locked the front end today and it made a big difference over yesterday. I felt like I had more control with the front locked and pulling also".

he griped about how tall it was and now he has gotten older. I have thought about trying to find him a TJ and put a 2" lift and some 31's on it for him to have to putt putt around town and out to the farm in.

I think that trans is 4:1 first, or real close

 

[fourwheelerjeff]

I think that trans is 4:1 first, or real close

real close, AX-5 with a 3.93 so crawl ratio on it is 76.71

 

[Fastereddie]

I had long questioned the need for a Doubler or Magnum. After doing some wheeling with the Magnum, I'm truly amazed at the difference. Now the game I play is if the trail is a 2 locker, 1 locker, or no locker rating. A lot of trails I do now with the Magnum are "no locker" trails.

I’m kind of the opposite. I flick the rear locker on as soon as I hit the dirt. When I come to an obstacle I flick the front on. After the obstacle, front’s back off.

 

[Bent77]

I’m kind of the opposite. I flick the rear locker on as soon as I hit the dirt. When I come to an obstacle I flick the front on. After the obstacle, front’s back off.

Having had both, I leave the rear unlocked a bunch

 

[mrk5]

I’m kind of the opposite. I flick the rear locker on as soon as I hit the dirt. When I come to an obstacle I flick the front on. After the obstacle, front’s back off.

If it's a sketchy obstacle that looks like I could do it but would also get real ugly if I lost traction, I'll throw a locker on just in case. So I'm not totally committed to the "no locker" idea. The last time I was at Blazer Bash, Stephen from ORD drove one of their trucks up Hell's Gate with no lockers. I wouldn't try that one, but maybe after you've done it a hundred times it feels different.

 

[skunked]

I kept it simple and went with the skinny pedal trigger switch for the lockers.

 

[Magikal]

OP here. My shit is powered by a tuned 7.4 vortec. Lincoln locked rear and zip locker competition model in the front. Having ran the 203/205 setup i don't think i would do it again. I would go for either a magnum box or 241/205 or a 241/241 combo. Definitely ditch the 4l80e.

Live and learn though. That tuned 7.4 is nuts. Team208motorsports is the bomb for tunes!!

 

[6.2Blazer]

As mentioned the crawl ratio of the OP should be around 44:1 which is decent with an automatic. This type of question is hard to answer on a forum because it is all based on somebody's opinion and what they are used to...there is no hard data to go off of, no speed vs. RPM, feet per minute, etc... What is the OP comparing it to? What type of vehicle has he driven off-road previously? Did he drive the exact truck with a different setup, or was he driving something like a Toyota with dual low geared cases with a stupid 200:1 ratio? Speaking of which, you can't compare the crawl ratio between an automatic and manual transmission setup. Just like said above I would times crawl ratio by at least 2 for the automatic if you want to compare them.

My personal setup has a 34:1 crawl ratio (auto trans) on 40" tires and have never had an issue with it on the Eastern side of the US trails. Granted over on this side of the country most trails have loose slippery rock, ruts, and mud that requires wheel speed a lot of times. I do have the parts to swap from 4.10 to 5.13 which would put me down to 43:1 but it's not been that big of a deal to put it high on my priority list. Another buddy ran 45:1 on 40's with a stock 5.3 in a heavy truck for years and ran all the hardcore trails (Windrock, Harlan/Black Mountain, etc...) and was happy. Only recently went with a 2.72 planetary mated to a 205 on his new build, but mainly for the strength of the 205 and ability to twin stick (front digs, etc...). He just uses the 2.72 low range 90% of the time.

 

[mrk5]

That is true, for me as well. If I'm running just 1 case in low, it's the 2.72 low range. Occasionally I'll run just the NP205 in low, but that's if it's mostly just a flattish road.

 

[Hosalabad]

The 4.10s and 40s aren’t helping. I’d regear the axles.

 

[mrk5]

My buddy has 40's with 4.56 gears and an SM465 trans. The engine is a tired TBI350. The first couple times I drove it, I had a hell of a time not stalling it starting in 1st gear; the motor just bogged down. The next time I rode with him driving, I realized he always starts in granny low.