Dana 18 and 20 series transfer case

Can the Dana 18 or Dana 20 be "flipped over" for driver's side use on the XJ's-TIA

bxj said:

Can the Dana 18 or Dana 20 be "flipped over" for driver's side use on the XJ's-TIA

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If you don't mind me asking What makes you want to use a d20?

What is your planned use?

Sorry , but I was just dreaming of something like a short NP 241 Rocktrack or a StAK transfer case and was looking for a reasonably inexpensive( read cheap...) replacement in the local boneyards here in the great Midwest for my ageing XJ-Didn't mean no harm by my "newbie question-I just started looking around and found some Ford Bronco 1966 or something Dana 20's-I am needing/wanting something a little shorter and compact but can't afford those prices our " good friends" at the salvage yards are wanting for their Dana 300's-Just curious about those Dana 18 or Dana 20's being able to be "flipped over" to the driver's side for use with the XJ-TIA
Happy New Year !

bxj said:

Sorry , but I was just dreaming of something like a short NP 241 Rocktrack or a StAK transfer case and was looking for a reasonably inexpensive( read cheap...) replacement in the local boneyards here in the great Midwest for my ageing XJ-Didn't mean no harm by my "newbie question-I just started looking around and found some Ford Bronco 1966 or something Dana 20's-I am needing/wanting something a little shorter and compact but can't afford those prices our " good friends" at the salvage yards are wanting for their Dana 300's-Just curious about those Dana 18 or Dana 20's being able to be "flipped over" to the driver's side for use with the XJ-TIA
Happy New Year !

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Check with advancedadapters.com or novak-adapt.com I know they make a d20 adapter and if anyone has anything its one of those 2.

I am also considering a Bronco Dana 20 for my MJ. From what I understand, this case is pretty similar to a D300, but is already setup for drivers side drop. It only has a 2.46:1 low range, but if I combine this with a 203 range box then I would get 1:1, 2:1, 2.46:1 and 4.92:1. Since I plan to run a GM 5.3L V8 with a 4L60E auto tranny (which has a 1st gear of 3.06:1) I think the gearing choices would be pretty nice. I do have a bit of a concern over the strength of the case and the cost of adapters to get it all put together, but this is what I am considering. I've also read that the front output shaft can end up being a weak link on the D20 case if you upgrade the rear output to a 32 spline unit...which isn't cheap either. Jeff

See here

http://www.high-impact.net/transmission_and_gear/Tcase_Dana20EarlyBronco.htm

Happy New Year everyone and thanks for all the input-Today here in the sunny Midwest I back on my merry way down to the local boneyards to see if I can find that Dana 20 transfer case that I had earlier passed up because of my lack of appreciation and knowledge-Good to hear that the ole Dana 20's are still a cost-efficent + durable alternative to those nice Dana 300's-Nothing like these pages here at to enable XJ owners to make a informed decision-Hope no one has picked my Dana 20 up before I get there.
THX again.

Jeff 98XJ WI said:

I am also considering a Bronco Dana 20 for my MJ. From what I understand, this case is pretty similar to a D300, but is already setup for drivers side drop. It only has a 2.46:1 low range, but if I combine this with a 203 range box then I would get 1:1, 2:1, 2.46:1 and 4.92:1. Since I plan to run a GM 5.3L V8 with a 4L60E auto tranny (which has a 1st gear of 3.06:1) I think the gearing choices would be pretty nice. I do have a bit of a concern over the strength of the case and the cost of adapters to get it all put together, but this is what I am considering. I've also read that the front output shaft can end up being a weak link on the D20 case if you upgrade the rear output to a 32 spline unit...which isn't cheap either. Jeff

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Well, I stopped by a local yard today and found two early Bronco Dana 20's. An early one and a late one. I also found many NP205's (One Ford, multiple Chevy and Dodges) and quite a few NP203's (Chevy and Dodge only.) However, the guy wanted $100 per 20 and $150 for the "Boat anchors" in his own words! I passed. Also, I got a quote of something like $599 (I don't remember for sure as it is in my in box at home) for a Jeds machine http://www.jedsmachining.com/ 203to 300 adapter and a note that he does NOT make a 203 to Dana 20 adapter. That makes the Wild Horses http://www.wildhorses4x4.com/42.asp 203 to Dana 20 adapter at $550 seem pretty reasonable! Jeff

A related Question.. is there a way to run a centered rear diff and an 18? its hard to find offset rear ends that can hold their mustard withour spending a million.

or.. is there a way to give an 18 a center output shaft?
-bc

well now im looing into this d20 crap as an alternative to the 231/d300 doubler, it can be twin sticked regeared and is already driverside drop?

whats the desirable years to yank a d20 for this kind of setup?

wow im excited now!

As far as I understand, the Ford Dana 20's can be regeared to 3.15:1 (tera) and Jack Obrien has jp rock eater gear sets in a variety of ratios (3.0, 3.6, 4.10, 4.86.) http://www.offroaders.com/tech/jeep/Transfercases-specs-mods.htm and http://bcbroncos.com/drivetrain1.html. The tera gears are something like $700-$800. The JP Rock Eater gear sets are somewhere around $1500 I guess. AA has a 32 spline rear output shaft available for around $400.

Novak has this to say about the Dana 20's: http://www.novak-adapt.com/knowledge/model_20.htm

The biggest problem is the expense involved to upgrade the weak points AND you are still left with a small input shaft and a small front output shaft. The front output shaft is the same 10 spline unit that is factory for the rear. Supposedly later model units used 26 spline outputs, but according to Novak, the main shaft diameter on the two is the same so they feel the greater spline count does NOT equate to stronger shafts...and I think the 26 spline units were only on Jeep D20 cases. Now think of 2wd low front digs with the same 10 spline output that is known to break in the rear output. I would be concerned about that although many folks use the d20 with big tires and big engines without fail. Here is a picture of the late model 26 spline front output from Billa Vista's Jeep Dana 20 teardown http://www.pirate4x4.com/tech/billavista/PR-low20/DCP_9458.JPG. I couldn't find the pic of that broken 10 spline rear D20 shaft that I saw, but anyway, it was broken at the yoke.

The input is 6 spline and doesn't look too terribly large in diameter to me. A stock Jeep NP 231 is 23 spline! What is the standard input spline count and diameter on a D300? Just some more inf. Jeff

xDUMPTRUCKx said:

well now im looing into this d20 crap as an alternative to the 231/d300 doubler, it can be twin sticked regeared and is already driverside drop?

whats the desirable years to yank a d20 for this kind of setup?

wow im excited now!

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The d18 is a passenger side drop.. front and rear Not sure about the 20.
Do you have pics of your doubler posted somewhere? I'm interested.
thanks,
bc

Brian Carpenter said:

The d18 is a passenger side drop.. front and rear Not sure about the 20.
Do you have pics of your doubler posted somewhere? I'm interested.
thanks,
bc

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Brian, I don't think anybody in this thread actually has a Dana 20 doubler. We are just talking about perhaps getting one. The Dana 20 comes in passenger side output (Jeep, IH) and drivers side front output (Old Ford Bronco.) Jeff

BTW, I may have been wrong about the Ford input spline count. I think it may be different than the Jeep Dana 20's whch are 6 spline. Jeff

bxj said:

Happy New Year everyone and thanks for all the input-Today here in the sunny Midwest I back on my merry way down to the local boneyards to see if I can find that Dana 20 transfer case that I had earlier passed up because of my lack of appreciation and knowledge-Good to hear that the ole Dana 20's are still a cost-efficent + durable alternative to those nice Dana 300's-Nothing like these pages here at to enable XJ owners to make a informed decision-Hope no one has picked my Dana 20 up before I get there.
THX again.

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where in KS are you from, I would like to come and see how this turns out or if close to me, maybe help/drool over your jeep.

The dana 20 is what I had behind my T 350 and a 350 ci Chevy... it held up well.... Geared very low too.... ... Not to de-rail thread but here is a photo.... This was one of 3 that I had....

Brian Carpenter said:

A related Question.. is there a way to run a centered rear diff and an 18? its hard to find offset rear ends that can hold their mustard withour spending a million.

or.. is there a way to give an 18 a center output shaft?
-bc

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I've heard of people running crooked rear driveshafts from the d18 offset to a a centered rear end. Its not offset that much. But.. it prob wouldnt do good at hwy speeds.

There are offset rear ends out there.. some FSJ had a rear D44 offset.

some landcruisers have had offset rears as well, and are great axles.

Okay, I'm looking at this as well (for my '82 Spirit/Eagle project) I want to hook up a D20 behind a 727 for a "used to be 2wd" car. LH drop (I have an AMC Eagle front axle already and the Eagle engine crossbar and axle will bolt right in. Especially since I want to do a lift at the same time to clear 33/9.50/15s) Anyone get that far yet? AW4/D20 LH drop?

http://high-impact.net/transmission_and_gear/vehapp_wrangler.htm#Bronco Dana 20 Wrangler

This is a Bronco D20 setup to mimic a 231. In this form it should bolt right up to an AW4. Does this help?

Here's a Klune/Bronco 20:


Jeff