Auto vs. Manual Transmission Question

Someone who understands the operation of the Torque converter answer a question for me. Take a Jeep with a 4.0l. This jeep has 5.38 gears and a

2.72 transfer case (231 or 242). If you have a AX-15 5-speed with a 3.8 1st gear ratio and a 42re 4-speed automatic with a 2.7 1st gear, you can do the math and by numeric value the AX-15 has the better crawl. But here is my question....Does the torque converter come into play so that you are effectively getting a decent crawl with the automatic even though the manual has the lower first gear? Pardon my ignorance.
Reply to
D McMorris
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You will have an unusual setup with those 5.38 gears (normally reserved for the 4 bangers!)... but as I understand the automatic gives you a virtual low gear... only as fast as the skinny pedal makes it. BTW there is no excuse for your ignorance!

-- JimG

80' CJ-7 258 CID 35" BFG MT on 15x10 Centerlines D44 Rear, Dana 30 Front. SOA 4.56 Gears, LockRight F&R Dana 300 w/4:1 & Currie twin sticks Warn X8000i w/ dual batteries
Reply to
JimG

Reply to
L.W.(ßill)

Reply to
L.W.(ßill)

Housings will accept any ring and pinion! (what's a real Jeep if its not a CJ?)

JimG

Reply to
JimG

BTW the axles came from a International Scout and a Grand Waggoner. :) D

Reply to
D McMorris

Reply to
L.W.(ßill)

While I have you attention Bill.... Any opinions on the NP 242 Select Trac Tansfercase?

Daren

Reply to
D McMorris

Reply to
L.W.(ßill)

Hey Bill,

Here in lies the dilemma. I currently have a front Dana 44 out of a grand Waggoner with the drop that matches the 231(currently in my jeep). I have the opportunity to put this Grand Cherokee 4.0, 42RE, and 242 as a whole into my YJ at a price that is UNBELIEVABLE (less then each piece would cost at a salvage yard, and I drove the vehicle last weekend). Now, I agree that the chain driven 242 is not in the same league as the gear driven 300, but is still IMHO it is a step up from the 231.

If I wanted to go to the 300 I would have to do one of two things; Buy a flip kit from Down East Off Road (45 minutes from my house) or swap out my front end to a 44 with the right hand drop. Having a spring over on a waggy front end requires a tremendous amount of prep. The differential side has the spring perch cast into the housing. This makes for approx. 4 hours of grinding to make room for the perch to be relocated to the top. Even though it's not gear driven, how many 231's and 242's are on the trails in YJ's, TJ's, and ZJ's? I'd just about bet it's probably 2 to 1. I personally have never witnessed a failure of a 231 in all the years I've been crawling. Not to say it has not happened, I just have not witnessed it. BYW the original Hummer also runs a version of the 242.

D
Reply to
D McMorris

Reply to
L.W.(ßill)

At which time you count your loses and maybe spend the $700 for the flip kit or $500 for the new front and gear setup. As always, thanks for your input.

D

Reply to
D McMorris

Reply to
L.W.(ßill)

Isn't that what the flip kit does. When you clock it you are only turning it up to get rid of the portion that hangs down lower your ground clearance. The flip kit is the only way I know to get it to come out on the drivers side.

D

Reply to
D McMorris

The short answer is "yes". You can get good torque through a torque converter even at 0 mph. The fact that you can effectively run your engine rpm up a little bit gives you the same advantage as lower gearing... to a point.

Reply to
TJim

Reply to
L.W.(ßill)

The Crawl Ratio is a number that says how slow you can go without fear of stalling. An automatic can not stall, therefore in has an infinite Crawl Ratio. You can twist the motor out of an automatic equipped Jeep with very low gearing and a very high crawl ratio because the brakes may not be able to overpower the engine. I have heard of some drivers with autos that must shift into N when they actually want to stop.

Reply to
Jeff Strickland

We are talking about the same thing bill. So my statement about expense comes into play. Maybe the 300 after I explode the 242.

Reply to
D McMorris

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