Transmission Options for Early Broncos 

Congrats Jon! It’ll be a great upgrade.

Should be a fun project!

Awesome vid!!!!! I think I’m going to upgrade to an AX-15, when I’m get there.

Glad you won’t put Chevy parts in your Bronco, nothing irritates me more than seeing a sbc in a Ford any year

The big things when I installed mine are front drive shaft tube size. Needs to be a skinny/small tube so it doesn't hit the pan. Modify the factory trans cross member to clear the tcase adaptor. build new frame mounts for the cross member out of 3x3 angle iron. order a lokar flexable dipstick. Also need to order a lokar shift rod kit to mate it up to the factory column. Also I'd very very highly suggest a 1in body lift minimum. The trans length puts the tcase into the floor support at the back of the tunnel. Then really consider gearing. 4.56/4.88 is where I'd start. Im running 35's and 4.10's. while it cruises nice at 70mph and 1900rpm its not in the power band so any hill it unlocks the torque converter to get the rpm up. I will be going with 5.13's as I also plan to build an overlanding trailer.

If you are interested I have a AOD/AODE/4R70W modified crossmember that I bought and ended up not using

I have 4:56 gears in my 73, with a c-4, but I have 33x12.50 tires, so I can’t go highway speeds with that stock 351?, I’m not sure which transmission to go with, if I went with a nv3550, I wonder how much hassle it is to add a clutch pedal?, or is an Aod a no brainer?

Did u ever installed the 4r70w? U have a newer videos and you mention a c4 So what happen

Does your bronco have a Dana 30 or 44. Can you do a video on how to replace the hub for Dana 30 if you have it

You gots too much extra loot laying around! Have fun

Do you have 3.5inch lift on your bronco and what size tires are you running currently, it looks good going down the road.

i have 4;56 c4 and 351w. should have 35" but 33" tires. freeway not fun but i will get there.

where did you get your wheels on your bronco( i've got a 79 with the factory wheels on it and i like yours

Looking forward to the Install or upgrades :) Did you consider the 6R80? I think adapters are available or coming shortly.

What electronic controller will you be using?

AOD was based off the FMX not C4

why not the 6R80 ?

Let me know if you need any help.

Take the Prius to Windrock this year!!

What about e4od

Would you mind posting those links that you referenced? I think there was one to classicbroncos.com and perhaps one other. Thanks in advance!

You should just put a 5 speed manual in it

Adding a 4r70W may not be your best option. For a freeway flyer with 4.56 gears and 35" tires the 4r70w works fine but out on the trail you won't see much difference. For the lower costs you could have an Atlas transfer case with the c4 trans and 3.50 and 35's and end up with both the freeway flyer and rock crawler with a much stronger final product. Let's look at the numbers. The c4/3.50/35 combo at 65 mph nets you 2320 rpms. This combo on the trail with an Atlas 2sp would give you a 37 to 1 ratio. The 4r70W/4.56/35 combo at 65 mph nets you 2132 rpms. This combo on the trail with the Dana 20 transfer case will give you a 30.3 to 1 ratio. So lets recap, the c4/Atlas combo nets you the nearly the same freeway rpms and higher crawl ratio with the added strength of the Atlas transfer case and use your c4, drive shafts and existing gears. Cost 2320 dollars. The 4r70w/4.56/35 combo gives you nearly the same freeway rpms but a 23% higher trail ratio but you do get a 4sp trans. which on the street won't make much difference and on the trail will drive you crazy. Cost approx. 3650+ dollars Just something to chew on. Good Luck.