AOD Transmisson for 302 then 347 Stroker

[OsteoBronco]

1st Thank you all for your previous input. [/I][/B]

I am keeping my 302 engine and updating the fuel system for a Sniper EFI. I have a family connection to a transmission shop.

What AOD transmission and transfer case would you recommend to be used today with the 302 and someday with a crate 347 Stroker engine?

My driving in south FL will be stop and go around town and short 15 to 30 miles on HWY 95 at 70+ . (Not sure if I want to go 70mph but anything slower and you are a driving hazard.)

This bronco will not be an off-road rig.

 

[Broncobowsher]

4R70W from a '98 - '01 V8 Explorer for transmission

Transfer case will be 3 choices, my least favorite to best choice...
Cheap, strong, heavy, crappy low range, probably need full rebuild and new yokes to work, NP205
Lighter duty, better fit, better low range, not as strong and needs adaptors, Bronco Dana 20
Atlas II. Strong. Bolts right up. different low range options as you order it. Brand new. Costs more, but not really that much more.

 

[OsteoBronco]

Thanks

Does or can you put on an AOD to the 4R70W transmission.

For street and hwy do you have a suggestion for the gearing with 33 or 35 tires?

 

[doran4x]

4R70W is the updated version of the AOD. better gears. It does require a controller, $600 but is a very good trans. For street I would stick with your Dana 20. Adapter is required for new trans. I went with the ZF5 adapter but you can also get one that replaces the tail shaft of the trans.

Gears depending on tire size. I have 35” tires and run 5.13 gears but mine sees off-road. Look at a gear to tire and rpm chart to find one you like.


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[Broncobowsher]

Forget the AOD. Too many flaws. Typically to try and bring the AOD up to something good you get a 4R70W and put the guts into your AOD. Gets you about 2/3 the way of what a stock 4R70W is capable of.

Take the lock up torque convertor. The AOD it is not selectable. Not locked in 1st or 2nd gear, 60% locked in 3rd gear (has to do with how the power flows into the planetary set, 40% from the convertor and 60% from a direct shaft), and 100% locked in OD. There are tricks that you can do to the AOD. There is a non-lock up convertor and/or input shaft that keeps you on the convertor 100% of the time in all gears, but the slippage in OD is wasteful, wastes a lot of fuel into a lot of waste hear. Where the 4R70W the lock up convertor is selectable, on or off, in every forward gear.

Next are the shift points. With the AOD they are hard to change. When you do change them, you change all of them together. With a stand alone transmission controller for the 4R70W (that will work great with the Sniper) you can tailor specific areas of specific shift points. Upshift and downshift separate. Even make a separate set of shift points for low range. Because low range has a lot different shifting needs. And you can't do that with an AOD no matter what. You are pretty much stuck trying to run the shifter manually. With a 4R70W you can actually have an automatic that works as good in low range as it does in high range.

For gearing, 4.88 or 5.13 for the engines and gearing options. Not sure how you plan the 347, usually they are after a HP target so they need a little more RPM to be happy. The 4.88s with the 4R70W is like a 3.42 effective final drive, which is a good highway gear for a Bronco in the 33-35" tire range.

The 4R70W will also work nicely if you give up on that little 347 idea and get a 351W as a base engine, and build it with a 408 stroker kit. Those work even better in a Bronco over the 347s.

 

[rguest3]

4R70W and 4.88 Gears with the 35" Tires.

I too would install the 351W over the 347.

Add a 1" Body Lift to help with clearance of the 4R70W and the 351W.

 

[OsteoBronco]

Thank!

I now know how little I know about these things. lol

Will go to a 4R70W with Dana 20. If and when I swap out the engine I will look at the 351W. Not sure how much HP I will need to get groceries or driving down A1A.

 

[Broncobowsher]

It's not the HP you are after, it's the torque that throws you back in the seat. Torque is fun without the need for speed.