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Petersen's 4wheel & Off-Road July 2001, page 52, top left corner, "The Common Denominator," stated that the fast growing trend among rockcrawling competitiors use automatic transmission rather than the stick.

So I am curious to see what you guys have to say about this. What are the drawbacks/setbacks using the automatic tranny in our rigs besides the lack in compression braking? What are the benefits using the auto on the trails? Opinions may vary but it will give us more options to consider before upgrading our drivelines. Flame away fellas....

-nc

[ 09-05-2001: Message edited by: nightcrawler ]
 

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It seems that all the guys that wheel autos with me really have a lot of control on the rocks. They can stal out the torque converter and really crawl. I think they take a lot of decision making out of rockcrawling. I think they are overall better at going up rocks than a Manual.

On the other hand, I am doing my very best to make my rig as simple and bulletproof as possible. Adding a slush-box goes against the way I have built my rig from the beginning.

I don't like riding the brakes on steep decents either.

This past weekend after a big rain, I was wheeling with a guy with an automatic. On the rocks where I stayed in one gear we did equally well. One place where there was a dirt bank coming out of a river and it was wet, I could not hang with the auto.

If I had to start over, I would still go with the Granny Low, manual transmission.
 

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i almost got the auto, but opted for the sm420. i like the gearing rather than my brakes smoking, BOMB proof! jiMMy
 

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Where I come from, building a truck (Cruiser or otherwise) implies keeping it reliable and field-repairable above anything else. A manual transmission falls into this category, at least in my book, and that's my personal preference. That said, I've been in situations where an auto tranny would have made things a lot easier, like really steep, loose descents.
Like most things, it's a question of personal preference, but I agree that it's a growing trend among extreme 4-wheelers. I think a lot of it has to do withe availability of crawling options, in the past, if you wanted to crawl, you had to go get yourself a manual tranny with a granny low like the SM420. Nowadays, with so many crawling options, it's possible to run an auto tranny and not sacrifice gearing.
FWIW, I've never owned an automatic, but when stuck in traffic with the big pig, I find myself jealous of 80 series owners! <IMG SRC="smilies/smile.gif" border="0">
 

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one thing nobody mentioned is that you will get "torque multiplication" with an auto. this means that even though an auto usually is geared much higher (2.5:1 to 3:1 in first ) than the standards, it will allow the engine to produce much more low end torque. this is achieved by the torque converter. it is much easier to stop on a steep grade and take off without going backwards with an auto than with a 4 spd.
i am an auto believer myself but they do have some drawbacks.
1) very little compression breaking; we all know that and even a low gear set and low stall converter don't help a whole lot.
2) generally, if your auto develops a major internal problem on the trail you're getting towed out. your standards will let you limp home even with bad bearings and chipped gear teeth; most of the time anyways.
3) this is a point that most people overlook or don't know. i call it gear range.
say you have a rig with ultra low gears and you want the t-case to be in 4 low for a certain trail but you want to cruise along at about 10 mph. with an auto you have to let the trans upshift until you get to the desired speed. with a manual you can just take off in 3rd if you want and not have to worry about shifting. this might sound like a miniscule problem or just an inconvenience but if you use your rig everywhere, say rubicon, hollister and pismo, it's nice to have a greater selection of gearing for take-off sometimes.
anyways, as i always say:"2 feet, 2 pedals!"
 

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I have an automatic in my FJ40 and have not tried driving a manual on similar terrain so I will not comment on that. But I would like to comment on or raise a couple more points. You cannot push start an automatic. One advantage the manual guys have, especially the ones with super low gearing, is the ability to use the starter to pull them up a hill if the engine stalls or to start while in gear. Most of the good crawlers only use the clutch when going in or out of gear, never while crawling. I think an automatic is easier on the drivetrain. The fluid clutch action of the torque converter does not directly connect the engine to the rest of the drivetrain like a manual transmission clutch does. This would absorb some shock and help keep from breaking parts. I would like to hear some tales about the failure of automatics vs. manual. Many automatics seem fairly bulletproof and usually give some warning before failure. Even if there is a problem it seems to affect a single gear which makes limping home possible. Where you would be screwed is if the main hydraulic actuator went out and karked the whole transmission. I have heard that automatics are actually easier to repair than manuals. There are lots of parts and the idea behind their operation seems mystical, but manual rebuilds require strict attention to tolerances that take special tools and knowledge.
 

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I may use manuals in my cruisers, but I'd prefer autos (I hate shifting and using the clutch!) Go auto sucka!

Hey orange fj45 wagon, you got any pics of your wagon? I would love to see some!

Jeff
 

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there are a lot of situations where having an auto is nice but i love to have the full controll you can only get with a stick. i had a 68 camaro with 350 hp and 700r4 then i put teh motor in my cruiser with a h55f and my cruiser is faster than the camaro. i vow to never buy an auto again.
 

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Originally posted by TOOL PUSHER:
<STRONG>I have heard that automatics are actually easier to repair than manuals. There are lots of parts and the idea behind their operation seems mystical, but manual rebuilds require strict attention to tolerances that take special tools and knowledge.</STRONG>
i have to comment on this. I can rebuild a manual 4-5 speed in about one day. Automatics take up a whole weekend, you wanna talk about strict tolerances, i've had to buy more damn guages and mic's because of that damn automatic i rebuilt. I don't care much for auto's, nowadays things have changed. Auto trannies are not what they used to be, they are very reliable and very strong. Take the Allison tranny in the new chevy pickup's, that is one badass transmission. I like manuals, cause there simple, but i won't dog a new auto without owning one first cause they are built better now then they used to be. For crawling, it really could go either way, ultimatly its personal preference.
 

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A few points -

1. Automatics really, really don't like to get any water in them.

2. The 727 TF, TH350/400 and the Ford C4/C6 are all very durable, the 700R4 can be made to be durable. Other autos are not so great and they cost WAY TO MUCH to rebuild. Especially OEM toyota truck and cruiser trannys.

3. An auto can frag on you at any time leaving the truck undriveable or hanicapped but then so can a clutch. In the type of non rockcrawling trail riding and mud bogging that I have done here in VA I have seen way more clutches go than slushboxes. But a clutch can be fixed trailside, auto - no way. This is also not rock crawling and is with trucks running LOTS of horsepower.

4. Auto's are way easier on drivetrain than stick shift truck are - but they tend to overheat really badly when used in heavy duty aplications. With lots of horsepower, big tires and hard driving an automatic holds up better. Clutches are not a long life item in that situation. Rock crawling with relativly stock components in a truck that you care about? This is less of an issue. Mud bogging with a stick shift in a truck running 39.5's and 450 HP before you hit the nitros? Auto is your friend - you'd never be able shift that fast and you'd blow it up.

5. When you have a auto tranny fluid problem off road are you going to have 18 quarts of fluid handy? The few times that have seen someone run into this they were screwed.

6. You can push start an auto, but you have to put a special pump in it, but I have only seen that on race cars and I don't even know if you could put one of those pumps in a street driving vehicle.

Stumbaugh
 

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i have a few more points to add!
1) you should never give water a chance to get into any tranny! run a breather!!!!!
even if water gets in, you will make it home but should definetly change fluids as soon as possible; otherwise the internal parts of your tranny will start to rust eventhough there is oil in there, or ATF!
2) whenever i go wheeling, i bring enough spare fluids to change everything! call me paranoid, but if you run into a major problem and you're way out there somewhere it's nice to at least have some simple resources to get you back up and running.
i've had to help a guy repair his busted tranny(auto) cooler line on a grand cherokee at the little sluice in rubicon. he had no spare fluid and said that about 30 or so rigs (mostly jeeps) had driven by and when he asked them for some his reply was some laughter. either way, he made it home.
3) if you're going to run an auto, make sure you have plenty of cooling! run the fluid through the cooler in the radiator and then through an auxilliary cooler, preferably a honeycomb type. they're a lot more efficient than the old tube and fin design. alos does not hurt to run a small power steering cooler.
4) you can start an automatic in any gear as long as you bypass the neutral safety switch but i would not recommend doing this for everybody. can cause accidental starting in gear(common sense should prevail).
5) the only auto you can pushstart is a chevy powerglide and a couple of really early autos that you'd never run in a 4X4.
6) the most fluid and auto will hold is 18 quarts (ford E4OD and allisons), which you won't see on the trail. most trannies hold 10 to 12 quarts.
7) a couple of people have mentioned this allready but i'll say it again: autos are MUCH easier on your drivetrain!!!!! the smooth power and ttoraue application will save your gears and u-joints.
8) when i say that a major internal problem with an auto will leave you stranded i mean major!it's not very common and like somebody else mentioned, autos will let you know when there's a problem before a while before it's too late.
9) it's much easier to overhaul or repair a manual trans than an auto!
mannual trannies have on the average 50 to 75 components. autos start at 250 to 300, not counting hardware in either case. the valvebody alone on most autos has more parts than most standards.
anybody can rebuild a standard with well written instructions. same can not be said with autos, and they do require a lot more spacialized tooling.
i'll leave it at that for now, but do remember: IT IS AND SHOULD ALLWAYS BE PERSONAL PREFFERANCE!!!!!!!
 

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by the way, hey jeff!
can't post any pics right now, windows 2000 NT, you know. but should be able to in about a week. get back to me then and i'll send you some. thanks for asking. autos rule! <IMG SRC="smilies/bounce2.gif" border="0"> <IMG SRC="smilies/bounce2.gif" border="0"> <IMG SRC="smilies/bounce2.gif" border="0">
 

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I ran a TH400 + 3 speed case + 488 gears for several years. Never had a problem with the slushbox and quite honestly, abused it and did not maintain it in any way. I liked the auto in the rocks, and it shined in the dirt, mud, and hillclimbs.

This winter I changed to a SM420 and love it on the rocks. Bottom line, I have more fun wheelin the the granny manual. I am not a mud fan and if I was I would have an auto.

What I did not like about the auto on the rocks is when you hit a rock you could crawl up, however, when the resistance is gone (crest the rock), you lurch forward due to the TQ action. It is difficult to keep a smooth constant crawl without a lowered tcase, IMHO.

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Karl
 

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i have to agree with karl, but with a little bit of finesse and some power braking you can make it work! <IMG SRC="smilies/bounce2.gif" border="0"> <IMG SRC="smilies/bounce2.gif" border="0"> <IMG SRC="smilies/bounce2.gif" border="0">
 

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I had a auto on my last Cruiser. While it worked for me, I was not into rocks back then.

After my first trip thru the 'Con with my current truck, I decided to go with a manual granny geared tranny. Added the SM420 almost 3 yrs ago, and never looked back.

Everyone has an opinion, but mine is for a low geared manual.
 

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I have an Auto in my 40 and love it.I have yet to have any problems.Just keep them cool and there happy.
Jeff here is a pic of Georg's 45 wag...<IMG width=523 height=352 SRC="http://www.pirate4x4.com/ubb/uploads/dunejpeg.jpg">


<IMG SRC="smilies/devil.gif" border="0"> <IMG SRC="smilies/devil.gif" border="0"> <IMG SRC="smilies/eyemouth.gif" border="0">
 
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