Twin stick D20

[Celadus]

I was recently researching doing a twin stick conversion for my D20. I found an interesting "how to" from the International Harvester clubs. Apparently on the IH D20 each shift rod controls each axle. For example front axle can run (high-neutral-low) and back axle can run (high-neutral-low). So you could run just the front or the back in whatever gear you wanted to. Caution! could put axles in different gear ratio. This would be bad!
So my question is, Can an IH d20 be put into a 66 wagoneer? I personally have not even seen the IH D20 yet. Any insight would be appreciated.

[yorkdork]

Someone who might be able to help you out is porkchop.He is in the middle of doing just what your talking about,except he is using a Spicer18 twin stick for parts to use in his 20.He is a good guy with lots of knowledge.
Ralph

:D

[porkchop]

Thanks, Ralph. The best way I can help you is to let you read what "the master of the drive train" told me when I was looking into doing this very swap. This is written by scotty. He knows all there is to know about drive trains and what years used what combos and how to modify them. So here is what he told some of us on the board awhile ago:

The d300, d20 and np 205 are both set up basically, with a HI, N, and LOW position for the front, and the same for the rear.72wag you are correct that you can choose almost any combination-front in N, rear in low or high to select rwd hi or lo range, rear in N, front in hi or low for fwd hi or low range. Or you can put both in hi (4wd high range) or both in low (4wd low range), or both in N (if you wanted to tow it). Obviously, you want to avoid putting the front in low and the rear in high , since something will break trying to spin the wheels in different speeds, unless you’re stuck on some slippery green Jell-O, or have all 4 wheels off the ground.
With the fsj version of the d20, no internal mods are necessary. Put your shifter in N.now if you disconnect one shaft or the other, you will discover that you can move either rail to all 3 positions with the other side in N. all that is really needed is to add a second lever, and use the stock shifter to control one or the other. Id probably use the stock shifter to control the innermost rail, for the rear output. Another option is to build a bracket that replaces the big tube and stock shift box that will accept a currie twin stick shifter. That’s what I was gonna do until I picked up the 18. When I rebuild my friend daves xfer, were gonna make a twin stick for it using the stock u box for 1 of the rails. After that happens, I can give some more details on what I did (do).
PC-if you can get a whole scout 20 with twin sticks, I'd grab it. It is essentially the same case, and is a direct replacement for a jeep 20 no need to buy just the shift tower and rails (you will also need the rails to make it work)
One more bit of info: the scout 20,the cj 20,the 18 and the 205 have interlock pills that prevent you from doing cool stuff from the factory. It is possible to simply remove the interlock pills to move the rails independently, but then you have to be careful not to accidentally do the aforementioned front hi, rear low, or vice versa.
The 18 is different. He does not have the same set up (front hi, n, lo rear hi, n , lo). He has a 2wd/4wd lever and a hi, n, low lever. So it is quite acceptable to simply remove his interlock pill so you can access low while in 2wd. there are no FWD possibilities with an 18-just rwd, and 4wd.
With the other cases, it is possible to reshape the interlock spots on the rails with a grinder, and leave the pills in so that the rails will move just enough to let you select hi or lo with either stick and the other in N, but they will not let the rails move enough to put one side in hi while the other is in low. There was an article in Petersen’s 4WOR awhile back on modifying the 205 shift rails for a twin stick. A friend of mine did it this way in his 77 gmc, and he likes it. He almost tried to shift it into a hi/lo position, and was very glad it wouldn’t let him. This method, of course, is quite a bit trickier, and if a person wants to simply remove interlock pills, or if he has a fsj 20,he just needs to double check that he is not shifting into a hi/lo position. For example, if you want to drive in 2wdlow,make sure the front is n N, and not in high.


That is it. I hope it helps you.

[64Trvlr]

The twin stick lets you have 2 wheel low when you want to. To use this feature you have to disassemble the transfer case and remove the pills that keep the shift shafts from doing this. It doesn't let you run low on one axle and hi on the other.
:cool:

[ August 12, 2001: Message edited by: 64Trvlr ]

[scotty]

PC,thanx for the reprint-glad i didnt have to type that all again ;)

64trvlr,the fsj dana 20 with the U pattern shifter box does not have any interlock pills. all you need to do is manufacture a seperate lever for each rail.

this fsj version,along with any version(scout,cj ) that has simply had the interlock pills removed,WILL let you shift into a high/low situation.