Rebuild Dana 20 'twin stick'/Dana 300&/or Atla$

creeper

Member
Someday soon I would like to get more reduction and am wanting to go with a twin stick setup. From what I understand my options with my '78 Scout II with a t19 wide and my Dana 20 are:

1)rebuild Dana 20 and remove detents to convert to 'twin stick' Dana 20(this thread suggests it can be done...http://www.forums.IHPartsAmerica.com/transfer-case-tech/794-twin-stick-good-bad.html): Can add tera low kit to go from 2:1 down to 3:1 ish.

2)replace my Dana 20 with a Dana 300 for more reduction. Rebuild and add twin stick setup.

3)buy a really expensive atlas and forgoe the reubild but get some cash back at a swap meet later....two speed or four speed atlas? Four speed offers 2.72:1, 4.3:1, 11.7:1 ! It's like your choices are good, better, best...well over $3,000+!

Are there transfer cases I am overlooking? Also, I've heard of people putting two Dana 20's in-line...how does this work? I am trying to wrap my brain around this reduction topic so would appreciate some help on theory here.....so if my first gear is 6.36:1 and my Dana 20 is 2:1 on reduction than if two Dana 20's are inline the final reduction is 4:1 times me gear ratio of 6.36:1 to get 60:1 final reduction or whatever the term is??? Wouldn't two transfer cases make a true 'twin stick' or what ever ya' call it....just askin'?
 
Stak makes a transfer case also. Little cheaper than the atlas.

The twin stick is for controlling the front and rear axles separately. Putting two transfers together is a doubler.

I talked to you at the IHSFR. People were trying the ramp while we talked. I was going to ask you if you had a ham radio lic.? From our conversation, I think you would be interested if you don't already have one.

Nice Scout by the way!
 
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No, I don't have a ham radio but have a question...I need to talk with fellow hunters who are using regular motorola/cobra hand held radio's...I was thinking more along the lines of a cb...I am not sure what a ham radio is except that it seems like short wave or whatever....boosted up cb? Enlighten me, please since I used to have a cb when I was younger...not sure what my liscense number is anymore....?
 
Twin stick your d20 for now.

Shop for a d300 and swap that in. Put 4:1's in it if you think you need lower (I ran a wide ratio, 4:1's, 4.10's and 33's for a long time and there were times I wanted lower, but at a cost when you need to "power out").

Twin-sticking the d300 is super simple, and you can use the sticks off your d20.

Any other doubler or aftermarket t-case solution with a t-19 requires you converting the tranny to use a "6-bolt round" output pattern.... Like this:

p0000062.sized.jpg


(you can see the adapter there between the t-case and the tranny, I don't seem to have a picture of it with out the t-case) about a $500 or so adapter and tranny mod.
 
@Mark...thanks! Really helpful. Now to find a Dana 300....I am definitely going to twin stick the Dana 20 but will probably hold off on a teraflex low kit for it and buy one for the Dana 300 instead...:icon_rotate:
 
So let me see if I have this correct now...my final output at my tires will be (in four wheel low with a Dana 300@4:1) my first gear ratio is 6.36:1 and my ring&pinion are 4.56:1 so that would be 6.36 x 4 x 4.56 = 116:1 the transmission will turn 116 times for every one turn of the tires. Correct? This should be sufficient for doing a bit of crawling, eh?:icon_cool:
 
Yeah pretty much thats how you get a rough estimate. It also depends on the tire size. What size are you running? Anyway its going to feel like you can crawl at about anything over 100 imo.
 
I'm running bf goodrich t/a km2 33" tires on 15" wheels. I've found a number of Dana 300's available out there. Looks like a rebuild kit and a teraflex low kit will put me back like $1k so maybe $1,300 total cost for a used Dana 300 totally rebuilt with the teraflex 4:1 kit. I have suspension mod's in the planning as well. I'm shooting for this spring for completion...
 
I picked up this Dana 300 on craigslist...looks like it has been setup already for a twin stick, eh....?:icon_wink:
 

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I'm going to rebuild it and put the teraflex low kit in it so I'll see if the little 'football' is in there or not...?
 
The Jeep housings are much better to put the 4:1. The case is a bit more sensitive for the IH Dana 300. Depends on your wheeling but if its nothing hardcore with huge tires you will be very happy with the setup you are planning to use. The atlas can wait until the Scout gets more and more abused.
 
I have the later model Jeep Dana 300 that measures 11 5/8" so I will need the novak conversion kit, eh?

adapting the t18 & t19 transmissions to the Jeep Dana 300 transfer case

If I remove the 'interlock' pieces I should have a twin stick..if they aren't removed already....the adapter is fine since I am saving all around anyway....I'll have to get it up on the bench and check it out this week...perhaps tomorrow at the shop..heh, heh.:ihih:
You can remove them if you want, but really no need. I never removed mine on my 300 and like I said, the only I "couldn't" have was front-wheel-drive high. I only missed it once, and even then it wasn't a big deal.

Keeps you from accidentally shifting one into high and one into low. It is however a good idea to shim or put bigger springs in the detentes.
 
Yeah...buying an atlas takes all the fun out of it....I wanna play. So I'm thinking of using jeb's machine shop to make a Dana 300 with a np203 as a doubler. My question to the IH folks is how or can I hook this up to my t-19...novak adapter or? Not sure how this will work. I know I can just use a novak adapter for the Dana 300 Jeep as is but am not sure about the np203. With a teraflex low kit in the Dana I would end up with 1:1, 2.01:1, 4:1, 8.04:1 as my options...heh, heh, heh. And I would stick my toungue out at a four speed atlas (since I didn't have to buy one...:p ).
 
231/d300 is also an option. Little lighter and more compact as well.

Use the novak adapter to get the 6-bolt round, np231 reduction box bolts right on. Dd machine adapter, bolt on d300. Talk to Scout broker (or ss2 I think on this board) or dboy for cable shifters. Done. All it takes it money.
 
231/d300 is also an option. Little lighter and more compact as well.

Use the novak adapter to get the 6-bolt round, np231 reduction box bolts right on. Dd machine adapter, bolt on d300. Talk to Scout broker (or ss2 I think on this board) or dboy for cable shifters. Done. All it takes it money.

Mark...what is the 'dd machine adapter'? Piece between np231 rear drive output and Dana 300 input?
 
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