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Jeep gears in Bronco Dana 20

hooligan shmulligan

Red Skull Member
Jul 30, 2020
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Did a 2.46 swap for a friends CJ. So I got a Bronco case and Jeep gears left over. Another friend has been talking about a doubler project in his TJ. 231-231 is to long and don't want to do a 300 flip.
So the question is will the Jeep gears go into the Bronco case?
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I did the 18 gear swap in the jeep 20. Thats why I have jeep 20 gears and a bronco case. Trying to low buck this as much as I can, hopefully all my buddy is out is the NWF box and a dana 20 rebuild kit.
There's was issues with that swap if I remember. Been along time since guys did that.i thought guys put the bronco gears in the jeep cases.. I believe they were high prone to failure iirc.
You have to grind a couple spots in a jeep case and weaken an already very weak and thin case. I wrecked one or 2 doing the bronco swaps
I've already done the 18 and bronco slider 2.46 swap in the jeep case. Know I want to know if I can go the other way, jeep gears in a bronco case. Found an old post on pirate that you have to modify the shift forks. But no real solid answers.
Look up herm the o/d guys site
novak has all the gear info

There was also a goofy guy in sac/auburn area that was a dana tcase guru but hell if i know his name anymore. ?steve? Big heavy white guy and had an offroad/jeep buisness but that was also 10 years ago
He reminded me a lot of jim from dls in sac.
Did some more digging the Bronco T case has a bigger shift fork for the front out put slider gear. Hence why when building a 2:46 Jeep 20 you need the 18 gears and not just use all the Bronco gears.The Dana 18 slider has the smaller diameter collar for the smaller 20 shift fork.
In my case I have a few options hodge podge a 18 and bronco 20 shift fork together or weld a ring on the jeep 20 gear making the collar bigger so the bronco shift fork works. Only problem I see modifying the gear is since the idler shaft of the jeep gears is bigger the fork is extremely close to the gear.
Modifying the forks is more work but probably the better option.
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Jeep gears on the left , Bronco gears on the right
Curious If you ever got this to work? I'm doing the same thing as your friend with the eco-box/dana 20. I called Novak adapts a while back and they said it wouldn't work but didn't give me any reasons why.
Never went anywhere both of us had other projects over the winter. The TJ has since shit out the front drive line at 60mph and grenaded the t case. He's looking at an Atlas now.
I'd hate to steer you wrong but the only thing I noticed was the shift forks.
Thanks for getting back though, I'm sorry you never got around to it. I wanna do it because the 2.72:1 in the eco and the 2.46/2.34:1 in the bronco case gives a double low of 6.7/6.36:1 which I feel is too low, where as the jeep gears gives a double low of 5.5:1. I'm assuming that's exactly what you were trying as well. Thanks man I appreciate it!
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