Crawl Ratio??

[f5fstop]

Originally Posted by rkcrawl

There are advantages to both: Manual vs Auto.

I have run both in competive (UROC Rockcrawling competitions) environments.

The biggest advantage, IMO, is down hill engine braking. A super low crawl ratio in a manual transmissioned vehicle gives you excellent control of the vehicle (way more then an auto) as long at the tires have traction.

Auto's on the other hand are a ton easier to drive, you've got one less peddle to deal with and very granular control of the vehicle motion. And yes, the GENERAL consensus in the 4x world is a factor of 2 when considering the torque convertor in the crawl ratio, however its just that when CRAWLING at low rpms. Its not exact, nor scientific, but I can tell you from the seat of the pants, its noticable when crawling level or uphill grades. I drove my old rig with both, and the only change being going from a SM465 4 speed with a granny 1st gear to a Turbo 350 with a full manual valve body. The difference was VERY noticable. The TC is not a factor down hill. Thats the auto's biggest disadvantage (again, just my opinion) because you need to rely more on the vehicle brakes, rather then engine braking. I think the second biggest issue/concern is transimssion failure potential.

Are you saying in an auto the transfer case is not a factor? I just finished some extremely steep mountain roads in Canyonlands (park and area), and in 4-low lock, the car hardly moves downhill, in fact, you have to gas it a few times. In 4-wheel hi lock, it crawls a lot slower than when in 4-wheel non-lock. This was in first or second gear, not in drive.
I have also driven a Jeep manual down the same roads, and with the manual, I had to use the brakes (first or second gear). Granted the H3 has a 4:1 while the Jeep did not, but if I'm reading you correctly, you are saying the t/case has no affect on downhill? That I will dispute, since I have tried all the ranges and there is a noticeable difference.