Swap out C4 for AOD, any bolt in options?

[Sierra Backwoods]

I'll be turning around 2900 RPM's at highway speeds with my 4.88's and 35 in tires, does anybody know if an AOD transmission will bolt up in place of my C4, or am I looking at extensive mods?

I usually trailer it, but for local trips it would be nice to run down the highway in overdrive.

[TRAILBOUND]

a windsor bell housing is a windsor bell housing (excluding 64 and earlier)

but asside from a complete AOD w/ torq conv. I think all you should need is an adapter to the D20

[URL="http://www.bcbroncos.com/DRIVE%20TRAIN%20TRANSFER%20CASE%20ADAPTER.html"]http://www.bcbroncos.com/DRIVE%20TRAIN%20TRANSFER%20CASE%20ADAPTER.html[/URL

FYI there is a complete AOD located 100m from my present location

[904Bronco]

AOD will bolt in with an A/A adapter, two versions available with a later model more desirable. Rear output shaft needs changed, there is early and late shafts, must make sure that you get the right one for your trans. Early trans had oiling issues, which were handled with changes that latter ones have. I have an 86 (earlier) in my 75 Bronco, from a T-bird with Mustang brackets and EV cable. It was rebuilt at time of the modifications, oil issues were taken care of then.
C4 flexplate, with a stock motor, should work if it is a Bronco C4 and not one from a passenger car. (smaller torque converter) If you have a late "roller" motor with 50 oz imbalance, you need to use the AOD flexplate. There is some work to be done to make stock steering column shifter work, I used a Lokar top of trans shifter, which also required some modifications. Body lift is needed, mine has a 2 inch, not sure if a 1" will be enough. Line pressure adjustment with EV cable is VERY IMPORTANT as you can smoke the trans quickly if not right.

More than you wanted to know...

Doug

[TRAILBOUND]

crap i didn't realize my sticky didn't post right. If you go to BC broncos, they have the adapters that doug is talking about, they come with the new output shafts.

[highlander]

The AOD with a D20 is about 1.5" longer than the C4 so drive-line and crossmember mods are needed. The stock crossmember just needs to be moved back on the frame. A 4x4 truck AOD with a NP205 will work if you don't want to buy any adapters, but you will have to make a crossmember. Both are pretty simple installs.

[kwspony]

I've been told that AOD's aren't the greatest tranny's as they have to be adjusted right or they burn up. MikeC has one in his and a friend of mine's uncle rebuilt it for him. Also, you need to make a mod to the valve train or it will shift at will even if dropped to low. Not a good thing to happen in the rocks. They can be made better though. Check out a different valve body too. I may have a link to one if you need it.

[904Bronco]

Line pressure adjustment with EV cable is VERY IMPORTANT as you can smoke the trans quickly if not right.

I have never experienced the upshift from 1st to 2nd, while in 1st gear, under heavy RPM that others have written about. I also have Terra Lows in my d20. Like any auto trans, decompression braking is lacking in comparison to a manual trans.
Bauman engineering makes alot of upgrades for the AOD, pricey though... Many swear by their stuff.

I've been told that AOD's aren't the greatest tranny's as they have to be adjusted right or they burn up. MikeC has one in his and a friend of mine's uncle rebuilt it for him. Also, you need to make a mod to the valve train or it will shift at will even if dropped to low. Not a good thing to happen in the rocks. They can be made better though. Check out a different valve body too. I may have a link to one if you need it.

[Sierra Backwoods]

Wow, thanks for the info, guys. looks like it will be a while before I research enough to formulate a plan.

I just got my new parts in today (new spring buckets), so hopefully I'll have that new D44 front end mounted tomorrow. I'm playin' hooky!