Transfercase Selection
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Joined: Oct 2006
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Transfercase Selection
Well, i just bought a 76 with a 390, np435 and dana 21. The dana 21 has been spilt in half and I want to replace it with a better t-case. I wanted to use a np 205 but I already have a dana 20 sitting here. Any ideas on which is easier/ a smarter choice?
thanks
thanks
Postmaster
Joined: Dec 2002
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From: Southern Oregon USA
If it is a early Bronco Dana 20, it will swap where the 21 was, but you will need a different adaptor to make it work.
To swap to a 205, you would need to change the transmission to an A pattern 435 or T18 with a 31 spline output.
If it were mine, I would go with the 205. The 20 is a stout unit, but not for a full size.
Jason
To swap to a 205, you would need to change the transmission to an A pattern 435 or T18 with a 31 spline output.
If it were mine, I would go with the 205. The 20 is a stout unit, but not for a full size.
Jason
Post Fiend
Joined: Apr 2008
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From: Grants Pass, Oregon
wont the same adapter used to attach an Np435 4 spd to a bronco D20 also work to attach a bronco D20 to a F100 NP 435? are the D20's similar in strength to the D21's,because i see a lot of F100's that still have D21's,so im assuming they are fairly stout?
Postmaster
Joined: Dec 2002
Posts: 3,594
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From: Southern Oregon USA
I don't know if I would consider the 21 stout. IMO, they were a substandard transfer case for that application. Ironically, I think the reason that many of them survive is their main downfall as a good transfer case; Lack of a low range. Fewer moving parts and less gear reduction to the output shafts makes a difference. I regularly witness a 21 take abuse from 5000 rpm, dump the clutch and spin 38" Swampers launches.
Jason
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where is a good writeup on how to do an eb dana 20 swap. I knew it was possible, just not sure how to go about it. Also could i change my tranny to a 2 wheel drvie set up and use a divorced t-case. or is that way to much work.
Postmaster
Joined: Dec 2002
Posts: 3,594
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From: Southern Oregon USA
Remove your 21, the coupler yoke and adaptor. Cut off the threaded end of the output shaft on the transmission. Install the Bronco shaft and input gear into the adaptor and bolt the adaptor to the back of the trans. Don't forget the roller bearings. And then bolt the transfer case to it.
You will need to fabricate a crossmember as the Bronco 20 is supported by the adaptor differently than the 21 is.
You will also need to figure out a transfer case shifter. You can use a stock Bronco shifter, depending on which type of transfer case you have. I would recommend going with a twin stick arrangement.
Jason
