so i have a 99 taco with a 5 speed manual and a dual case set up, i am looking into the inchworm lefty with some low gears in one case and have considered an automatic tranny swap when i do, running 1 tons and 40's now as well

what are you guys running and what are the likes and dislikes, durablity, cooling issues? i have never wheeled an auto rig but understand why i might want one for hardcore rock crawling

just something i have been toying with

My auto (A340F) runs between 150-180 F usually, unless I'm pulling some long ass hill on the interstate. I'm running an aftermarket plate style cooler from IPT and have never seen the trans get any hotter than normal operating temp while wheeling.

One thing to consider is how log your t-cases will be geared. When I was running a 2-speed Atlas (3.8:1) and Inchworn crawl box (8.7:1 total) it was almost to low to hold back with the brakes, found it easier to flip it up in neutral every time I stopped. With my new 4-speed t-case (5.4:1) everything is good.

My auto (A340F) runs between 150-180 F usually, unless I'm pulling some long ass hill on the interstate. I'm running an aftermarket plate style cooler from IPT and have never seen the trans get any hotter than normal operating temp while wheeling.

One thing to consider is how log your t-cases will be geared. When I was running a 2-speed Atlas (3.8:1) and Inchworn crawl box (8.7:1 total) it was almost to low to hold back with the brakes, found it easier to flip it up in neutral every time I stopped. With my new 4-speed t-case (5.4:1) everything is good.
i dont quite understand why you wouldnt be able to stop? were you running stock brakes with giant tires or something? i could see that with my manual set up but not an automatic, i am planning on the 4.7 gears and then a stock set in the other

No I was running 6-piston Wilwood calipers on all four corners with a double diaphragm booster and 3/4-ton rotors that would throw you through the windshield. All I know is that if you go too low it will drive through any brakes you can put on.

i dont quite understand why you wouldnt be able to stop? were you running stock brakes with giant tires or something? i could see that with my manual set up but not an automatic, i am planning on the 4.7 gears and then a stock set in the other

Autos in gear are pushing all the time. So, when you have stupid low gearing, even the best brakes in the work won't hold it. Same way you can throttle through your ebrake very easily when left on.

This is why I am only running dual 2.28 boxes in my new ride. 78:1 crawl ratio is plenty for an auto imho.

Scotty

Yep - 78:1 is perfect for me too :smokin:.

Autos in gear are pushing all the time. So, when you have stupid low gearing, even the best brakes in the work won't hold it. Same way you can throttle through your ebrake very easily when left on.

This is why I am only running dual 2.28 boxes in my new ride. 78:1 crawl ratio is plenty for an auto imho.

Scotty

ok, but my dual setup isnt handling 1 tons and 40's so i have to go lower, i dont think you guys are runnning this big of a drive train are you? i need some lower gears to have the control i am needing and used to having while crawling with my previous set up with 36" tires and the same dual set up

ok, but my dual setup isnt handling 1 tons and 40's so i have to go lower, i dont think you guys are runnning this big of a drive train are you? i need some lower gears to have the control i am needing and used to having while crawling with my previous set up with 36" tires and the same dual set up


I'm not following the question - you are or are not running large tires and heavy axles? It really doesn't matter what you're running, if you gear too low you will be driving through your brakes regardless.

You're not factoring in the torque converter reduction, which with Toyota's is extremely high. I've heard it's a 2:1 reduction for the converter, but I always assume a little more conservative number like 1.5:1.

If you're saying you need more reduction for control, to avoid breaking parts.....that's a double-edged sword too.

I'm running 1-ton axles and 40's. When I was running the lower set up I was running 1/2-ton with 35's & 37's.

as my first post says that i dont know any of the factors about the automatic and how that works in this capacity, i have never heard anything about how a converter effects the brakes with low gears and what not and thats why i'm asking, just trying to get some real info to further my knowlegde(which i dont have for automatics) and if the auto is even an option for me in the future
i am not doing it to prevent breakage, the type of terrain i am in dictates alot of slow control and i cant do that with a clutch and the higher gear ratio that i ended up with after bigger tires, heavier axles etc... everyone says the liquid clutch is just easier in hard terrain and thats was why i was thinking about going that route, most likely i'll do low gears and just stick with my manual if it's not even an option really with lower gears

What they are saying is when you come to a stop with a manual you push the clutch in thus taking the power away from the trans, the auto you just push the brakes, but the trans is always in gear so it continues to push because the gears are so low it does not need any gas to continue moving the truck even with the brakes pressed to the floor.

my dad just swapped his dual set up in his 07 fjc on D60's and 40's too the 4:1 lefty case. he would be constantly rolling in low gear with his auto tranny. now that he lost the low range gearing, he still can crawl fine, but he isnt pushing through his brakes all the time.... and thats with the GM brake master cylinder...

so maybe just an auto and a dual case with standard gears in both...hummm

i have 2.28 and 4.7s...its stupid. id actually like to get rid of the 4.7s and go to two 2.28s

I'm not following the question - you are or are not running large tires and heavy axles? It really doesn't matter what you're running, if you gear too low you will be driving through your brakes regardless.

You're not factoring in the torque converter reduction, which with Toyota's is extremely high. I've heard it's a 2:1 reduction for the converter, but I always assume a little more conservative number like 1.5:1.

If you're saying you need more reduction for control, to avoid breaking parts.....that's a double-edged sword too.

I'm running 1-ton axles and 40's. When I was running the lower set up I was running 1/2-ton with 35's & 37's.

marlin told me awhile back it was like 2.3:1 for the a340 series trannies!:eek: i think its also posted somewhere on his site in the tech section or something?

i have 2.28 and 4.7s...its stupid. id actually like to get rid of the 4.7s and go to two 2.28s

I told you!

My 01 has 4.7's in the crawler box and factory gearing in the original case. I love it! I can run the crawler in low, factory T case in low, or compound low. Choices, Choices! My brakes will hold it all back, but it puts some major twist on all the drive train parts. I just pop it in Neutral when I come to a complete stop, I wouldn't change a thing.

i have a auto with a single case w/4.7 and its crazy low still powers through the brakes w/duals it was unstoppable so i went to a single case