Same crawl ratio...auto vs stick

[Steve98]

My question concerns transmissions more than the actual crawl ratio. I would think that two rigs with the same or very similar crawls and tires, would descend a hill at the same rate. But after driving different stuff, the manual seems to hold back better. Is this because of the torque converter not locking up? Also, would an auto with 100:1 idle through stuff or up hills like a manual of the same gearing?

[WJJEEPIN]

My question concerns transmissions more than the actual crawl ratio. I would think that two rigs with the same or very similar crawls and tires, would descend a hill at the same rate. But after driving different stuff, the manual seems to hold back better. Is this because of the torque converter not locking up? Also, would an auto with 100:1 idle through stuff or up hills like a manual of the same gearing?

The manual is generally geared lower than an auto therefor causing it to crawl slower.

[Steve98]

I said same crawl ratio. The individual gears don't really matter.

[IndyZJ]

Manuals give (more) compression braking, which would make it idle slower down a hill. Some aftermarket valve bodies do the same for automatics, though. Autos are much easier to drive (no shit), especially offroad since the torque converter keeps the engine from stalling.

[ATL ZJ]

Usually when you calculate crawl ratio for an automatic you multiply your result by a 2x factor to account for the torque converter. If you don't do that, if you have a manual and an auto with the same crawl ratio, the auto will "act" lower. You can't really look at it as simply as you are doing. Just understand how they both work and it will make sense to you.

[Steve98]

I realize they don't act the same. So I guess no, would be the answer. Does anyone here use a shift kit or modded valve body? Would there be any real advantages to it?

Although I really prefer a manual in all cars, the jeep is a different story. I like the slushbox for my jeeps purpose. I just thought maybe there is a way to get more compression braking feel from it on descents.

[ATL ZJ]

Gotcha. A full manual valve body will accomplish mostly the same thing as as manual, since the trans won't change gears on its own and you will have to shift it manually. IMO a reverse full manual valve body in a beefed auto is the ultimate for a wheeling rig. It just comes at a price.

The advantages to an built automatic on the trail are its ease of use and its smooth power transfer.

The advantages to a granny manual are simplicity and a source of inexpensive low gearing.

There are some excellent threads on pirate about this that are stuffed with more tech than you can stomach in a single sitting.

[cLAYH]

I have converted one offroad rig form stick to auto and one rig from auto to stick. Nothing else changed on the rigs.

In both cases I found that the auto was nicer to drive offroad and gave me more control as I could "feather" the gas pedal more over rocks however I did not have near the same compression braking going downhill. Unless you can manually lock up the TC going downhill the TC will "slip" and not give as good compression braking as a stick. Going uphill the TC is working and I havn't noticed a difference there.

For reliabiltiy I would say sticks are better, less to go wrong. Autos don't like water in them, don't like to get hot, don't like holes in them. Although I've seen guys slip clutches powering up an obstacle with big tires or completely ruin a clutch by getting stuck in deep mud and then pushing in the clutch pedal. This allows mud/dirt to get between the plates and within 20km of getting out of the hole the clutch is toast and usually takes the flywheel with it.

[DJJordache]

kinda sounds like you would like to swap (if you have the 4.0L) to an AW4 with the AWshifter that can give the feel of an auto but with the total control of a stick

[Steve98]

No dice I'm afraid on the swap, plus my 44re was rebuilt only 30k miles ago. Thanks for the answers guys.