Decision: AOD, 4R70W or C6 + Atlas couple questions

[Broncobowsher]

Thanks everyone for your thoughts and suggestions.

it sounds like a junkyard 4R70W with the Bauman computer is the way to go.(not ready to go EFI yet)

First order of business is some extended radius arms so in the meantime I'll keep an eye out for V8 explorer's being parted out in craigslist.

Broncobowsher - you mentioned engine braking and OD. The 4R70W is a lockup transmission right? does that mean you can lock it up in low range?

how does the calculation work for engine braking?

1st - 2.84
Atlas - 3.8 (may go with 4.3)
gears - 4.88

52:1

I've always multipled that by ~2 to get my final crawl ratio to account for the torque converter so I would have about 100:1 crawl but how does that work out for engine braking?

I agree... i'll miss putting the 435 in granny gear and Dana20 in 4-low and creeping down an incline while the guys w/ automatics behind me have their foot mashed into the brake the whole time.

That crawl sounds right. Very close to mine but I only have 3.15 in the transfer case.

If you find an Explorer ('98 to '01) V8 that has all the goodies built in. Find one with AWD and the Atlas will bolt right on.

Sorry, the 2WD tailshaft is different then the 4WD. Can't just swap the tailhousing, doesn't work that way.

The Baumanator lets you program what gears the convertor locks in. One of my tricks is I added another button to the floor that lets me lock the convertor at will. Push the button (hidden under the carpet) and it locks up. Idle up steep hills at 600RPM with an automatic without touching a pedal. With that much gearing, idle right back down it as well.

The 2:1 multiplier only comes in when you have the gas mashed. Does not work for engine braking. This is why you always see people with there C4s complaining that they have no engine braking. Well they are wheeling with 20:1 crawl abusing the convertor to get into the 40:1 to get over stuff. The less you rely on the convertor to make it over stuff the better. coming up to a rock or a tree, digging deep into the throttle then popping up over the top is a sign of not enough gear and too much use of the convertor. Even without locking the convertor I can usually just idle up to something and walk over it with no or only a little throttle, just like a granny on the 435.

The 4R70W has about 14" pan length, the E4OD is about 20". The 4R70W will have 3 eletrical plugs; one on the single shift arm, one on the case (speed output shaft speed sensor which is not a vehicle speed sensor), and one going into the case at the rear passenger corner just above the pan. AOD will have a single plug on the very top of the case above the shift lever and the shift lever will be a double arm (other for the TV).

 

[OsideDave]

Thanks everyone for your thoughts and suggestions.

it sounds like a junkyard 4R70W with the Bauman computer is the way to go.(not ready to go EFI yet)

First order of business is some extended radius arms so in the meantime I'll keep an eye out for V8 explorer's being parted out in craigslist.

Broncobowsher - you mentioned engine braking and OD. The 4R70W is a lockup transmission right? does that mean you can lock it up in low range?

how does the calculation work for engine braking?

1st - 2.84
Atlas - 3.8 (may go with 4.3)
gears - 4.88

52:1

.

4R and Atlas (or StaK) sounds like a great combo. I would have sprung for this set up but I wanted a new engine so to keep costs down I kept C4 and got StaK to help w/ lower gearing.

 

[DanWheeler]

Oh man, i've just been reading about the Baumannator... thats a lot of electronics. I've been having bad luck with electronics lately I hope this thing is set it and forget it. The last thing I need is another device failing on me in addition to my xbox, zune, computers, cell phone...

do I need to order the baumannator with longer cables? I want to make sure I can tuck the controller up into the dash.

just found a 2000 explorer parting out - wants $150 for the tranny. 132,000 miles. Too many miles? guess I could have it rebuilt. How hard are they to rebuild?

 

[Dave]

just found a 2000 explorer parting out - wants $150 for the tranny. 132,000 miles. Too many miles? guess I could have it rebuilt. How hard are they to rebuild?

Depends somewhat on how it was used (oa abused). It should have another 50K of so in it. But it is a good time to spend a few hundred bucks to have it gone through.

 

[needabronco]

Don't forget to figure the Bauman computer and harness are $650. That adds quite a bit into your equation. That difference would get you really close to a 4 speed atlas from a standard atlas!


I challenge you to ask around and find out exactly who (besides Bax%)) has smoked an AOD in an early bronco's. I know a couple who have in mustangs, but the beat the crap out of them... But I've talked to dozens who run AOD's in their broncos and everyone seems pretty happy with them. I do agree the 4R is a nicer package, but definitely more expensive... I know I have 1 of each in the garage right now.

 

[Broncobowsher]

The Baumanator is only $425. Comes with an unterminated harness. If you get the plugs from the harness when you get the transmission then you don't need to spend the coin on the expensive harness.

 

[malcolmzilla]

Check out the 700R4 thread, you can get a pretty good one built for $1500 no core charge (TCI), non computer except for lockup, good ratios... Since you're going to an Atlas order it to fit anyhow.

 

[DanWheeler]

Check out the 700R4 thread, you can get a pretty good one built for $1500 no core charge (TCI), non computer except for lockup, good ratios... Since you're going to an Atlas order it to fit anyhow.

Chevy? what? no. I already have enough guilt about my brakes.

so... it looks like i'm just going to be picking up a 5.0 explorer w/ 4R70W.

as usual one thing leads to ten others. Not sure if I will get the baumannator anyway or just keep it stock. It could be awhile until I gather all the parts to install an EFI engine.

 

[needabronco]

Don't feel guilty about 'chevy' brakes. They are made by the Dana Corporation, NOT Chevy. Those part numbers are all universal.

 

[nvrstuk]

So why spend so much more coin on an OD trans when you only put 1-2K miles/yr? Doesn't seem to make much sense to me (not my rig tho) since you don't really put any miles on it.

Here's another option for durability, CHEAP, and great off-road gearing.

C4/KluneV/Atlas OR C6/KluneV/Atlas

C4 is cheap to build, bit lighter and doesn't suck HP

C6 is super tough in stock form but is a bit of a HP parasite

KluneV is super light, super compact, and is rated for over 5,000ft lb of torque. Easy shifting to more than double your gear ratio for both braking and climbing. In combination with the Atlas (which it was designed to bolt to directly) this means you can idle down ledges with an auto...even a C4. I saw one on Pirate in "super condition" for $600 last month.

http://www.high-impact.net/transmission_and_gear/Klune-V_Atlas Combo.htm

No adatpers

.02