Dana 20 trivia

[Viperwolf1]

Anybody ever swap J style shift rails into a T style transfer case before? I thought it would be straight forward but I called one of the vendors to buy some extra J rails and was told that it wouldn't work. Other than the gears and rails/pills I can't figure what could be different between them. I have rebuilt both T and J cases before but never at the same time and never tried to swap parts between them. I also noticed that Jeff's lists the rear output shafts separately beween the T and J. Anyone know the difference there?

 

[telcolineman]

The rear outputs are the same, Wild horses says the front outputs are different. The J shift uses a different style snap ring setup and bearings, They also say the detents and shift rails are different. But they don't say why

 

[Viperwolf1]

The rear outputs are the same, Wild horses says the front outputs are different. The J shift uses a different style snap ring setup and bearings, They also say the detents and shift rails are different. But they don't say why

As I remember there's a snap ring on the T front output that is not used on the J. I don't know about any difference in the bearings.

 

[hrleydavdsonEB]

Internally I believe that the T-type transfer case has a lower 4-low ratio then the J-type the pre 73s (T-shift)had the 2.46:1 low, and the 73 and newer had the 2.34:1 low (J Shift) so the actual gears themselves are not interchangeable. I have delt with both the J-shift and the T-shift but never interchanged them.

 

[Viperwolf1]

Internally I believe that the T-type transfer case has a lower 4-low ratio then the J-type the pre 73s (T-shift)had the 2.46:1 low, and the 73 and newer had the 2.34:1 low (J Shift) so the actual gears themselves are not interchangeable. I have delt with both the J-shift and the T-shift but never interchanged them.

That is correct and the reason why I want to change the rails.

 

[bax]

OK I am interested. Why do you want to do this? Are you trying to twin stick a T by using a set of J rails?

Bax

 

[Viperwolf1]

I have a J in the bronco along with twinsticks. I also have a spare T tc. I want to rebuild the spare with the J rails and swap it into the bronco. That way I get better low gearing and I don't need another shifter. I know there's not that much difference in the gearing but I figure it's 5% more torque when I need it most.

 

[bax]

You can grind the T rails to make it a twin stick. It should still work with your shifter.

 

[Viperwolf1]

Thought of that already. I'd need to weld some ears on the end. Problem is I don't have a welder anymore.

 

[Mark]

That's very coincidental Phil.
I just picked up a t-shift Dana 20 this past weekend to rebuild and twin stick just for that added little bit of gearing also!
If the J-shift rails fit, that'd be easier than grinding the t-shift rails.

Here's something I've been reading...
http://www.wt4x4.net/tech/twinstick.htm

looks like the front output shafts can be swapped out.

 

[bax]

Thought of that already. I'd need to weld some ears on the end. Problem is I don't have a welder anymore.

No you dont. The ends of the t Rails have a slot and a hole in them. Bolt a flag into the slot and drill you a hole in the new flag.

 

[Viperwolf1]

That's very coincidental Phil.
I just picked up a t-shift Dana 20 this past weekend to rebuild and twin stick just for that added little bit of gearing also!
If the J-shift rails fit, that'd be easier than grinding the t-shift rails.

Here's something I've been reading...
http://www.wt4x4.net/tech/twinstick.htm

looks like the front output shafts can be swapped out.

Thanks Mark. That confirms the difference I remember on the front shaft. I'm still trying to find some spare J rails. I want to keep my old tcase intact as a spare.

 

[broncobandit]

I put T-shift gears in my J-shift D-20 that worked out just fine.

 

[bax]

That was easy.
broncograveyard.com/bronco/i-11636_shaft_rail__front_66-72.htm

Crap you said J shift rails.
broncograveyard.com/bronco/i-11639_shift_rail__rear_dana-20__73-77.htm

 

[Viperwolf1]

That was easy.
broncograveyard.com/bronco/i-11636_shaft_rail__front_66-72.htm

I called them today. They don't have any J rails. I think I might try your idea of bolting some flags in.

 

[bax]

I have 3 -20's sitting around. All of them are T 's no j rails to send you.

 

[Viperwolf1]

a little update

I received some J style rails and tore down the T style case. It turns out that the J and T rails are different lengths complicating the simple addition of flags on to the T rails. Also the pill cutouts are different as was expected.
Something that I didn't expect was the front output shaft without the snap ring. Maybe it was phased in before the rail change or maybe it was replaced previously.

 

[ken75ranger]

How about making a piece of linkage going from the J shifter to the T ends? If you can then you can put in either D20.

 

[Red steed]

I asked this same thing a while back. But didn't get much feedback. I wanted to do the same thing have the J-shift with the T-shift gears. .I don't see why they won't work If the case is the same.I got another T-shift transfer case to rebuild to go in my 71 and the one I got came out of a 73. It was a T-shift but everything in it was J-shift. I found this out when Istarted needing parts for it.

 

[Bronchole]

It looks like the shift rails should be compatible. If you look at them from the right to left they look like the notches are all in the same functional areas, maybe a bit different but in the same areas. All of the additional length looks like it is just extensions of the rails to support the tabs for the J-shifters.