Divorcing a D20 transfercase in '77 J10 SWB?

[HI-TECH REDNECK]

im sure someone is going to tell me this is more work then its worth or not going to be durable enough or whatever, but that's OK. i was talking to a buddy tonight and he made the comment about liking divorced transfer cases. that's when the light bulb turned on in my head....

a little while ago i bought a Dana 20 transfer case with the tranny and adapter it came on and shifters. problem is, the trans is a BOP TH400 and i have the AMC TH400. so to put the Dana 20 on my AMC trans i need to change the output shaft in my trans with the one from the BOP trans. this divorced case idea got me thinking. if i mounted it up divorced instead of married, then i can make an intermediate drive shaft and use that as a way of adapting the splines in a way....

so i want to know what you guys think about this. from what little thought i have put into it so far (in the last 15 min only) i figure i need a plate to cap off the end of the t case so it doesn't leak, i can fab into this a mounting system which will help securely hold the case into the truck so it doesn't fall out :eek:. then all i need is some yokes that fit the splines on the output of the trans and the input of the t case and fab them up on a drive shaft.

another benefit to divorce mounting this case i see is the ability to "attempt" to place the case so that i can use my stock drive shafts front and rear, and better clear the tranny bell housing with the front drive shaft by offsetting the case to the passenger side of the truck a little bit.

my future plans for the truck will likely involve drive shaft mods when i do the soa and shackle flip in the back, however im not ready (financially) to do this yet. i would like to get low range in the truck as soon as i can because i have the stuff to do it and then i can run larger then 30" tires and still be able to drive off road. 33's with out low range are really more of a drag than any fun with the muddy hills and rocks we have up here. so if i can get low range in and working, then i can run some 33's or 34's and have the truck still be functional both on and off road. (i have a matched set of 5.38 gears that have been welded to the carriers for the front and rear of my truck, these will go in when i do the soa/shackle flip and larger tires). so 2.0 low range will be plenty low enough i think :D.

im a broke college kid trying to find a job, so money is non existent. however, i do have a CNC class this semester where i could make any plates i may need for this. i don't see any reason this wont work and would be considerably weaker than a married set up provided i build the mounts right. im thinking leaf spring style bushings to mount the case to the frame or cross member whichever i end up doing (or both). my time frame for this project is some time in the next 6 months to a year (basically whenever it gets done is fine with me).

commence discussion :rolleyes:

[HI-TECH REDNECK]

ok so i just got reminded by another buddy that i cant divorce the dana 20 from my AMC TH 400 with out tearing my trans apart and changing output shafts because i need to mount the dana 20 input gear on the output of the trans. so this one factor pretty much blew my hole idea out of the water....:mad: what a bummer......:banghead:

[Ron H]

Took the words right out of my mouth. Besides never mess with what is already a great t-case!! lol.:thumbsup:

[HI-TECH REDNECK]

so your dana 20 holds up well behind the 401 with the 4.56's and 40's eh??

my target for this truck is to be on 36's with soa/shackle flip on the stock d44's and the 360. but i got a set of used 5.38 gears fully welded to the carriers. i think it should be a pretty cool set up with the D20 in there once i get it all done :rolleyes:

[Ron H]

Yes its holding up real good, have'nt had any trouble, other than as soon as the budget allows, i am going with the tera low gears, other than that everything holds up good. You should be fine on the 44's, but if i were you i would check into the molley shafts just for extra protection and reliability, i have a 14 bolt ff, and a 60 up front with molley shafts.

[HI-TECH REDNECK]

i have a complete spare set of shafts with new u joints in them from my donor front axle i got the gears out of. plus im pretty easy on the skinny pedal and can tell when im pushing stuff too hard. i think ill be alright, especially since ill have more gear then i know what to do with so i shouldn't have to hammer on things super hard MOST of the time :rolleyes:. if i do blow all my spares real quick when i do get on er ill look into higher quality shafts, but till then i think ill be alright for a while.

the local club here is VERY knowlegeable and a great group of guys. they build some wicked stuff and i have learned a lot from them. its been a good time :thumbsup:.

good to hear some real life experience for the D20. the group here doesnt favor the D20, but im almost the only FSJ guy here so they are all chevy, ford, or yota biased....plus they wheel pretty dang hard too :drivin:

[Blue & Gray]

I had a similar idea and have allready began gathering parts. My build for my J-10 is 258, AX-15 2wd, Np205. I allready have the divorced Dodge 205 and the AX shouldn't be hard to locate. I like the divorced set up for several reasons. Clutch jobs are a bit easier, puts some more weight towards the rear and it helps driveshaft angles alot on a lifted truck, ultimately the divorced box is whereever you fab it in.. I want the cheap 5 speed that bolts in also and a hydraulic clutch. I am thinking Mild SOA Daily Driver/Random Wheeler on 35's that is using common off the shelf stuff for repair and maint.

[HI-TECH REDNECK]

yeah, my buddy told me to run a 2wd TH400 with a divorced 205 into another divorced 205. then i would have a mile long front drive shaft, shorter rear drive shaft, and a wicked doubler :D . i could do that if i put my output shaft from the BOP trans into my trans, and got two 205's, but that's more parts i don't have and i still need to tear my trans apart or change trannies.

[imiceman44]

yeah, my buddy told me to run a 2wd TH400 with a divorced 205 into another divorced 205. then i would have a mile long front drive shaft, shorter rear drive shaft, and a wicked doubler :D . i could do that if i put my output shaft from the BOP trans into my trans, and got two 205's, but that's more parts i don't have and i still need to tear my trans apart or change trannies.

Yeah the AMC th400 never came with a D20 so the only way you will use your D20 is by tearing into your AMCth400 which might feel like too much now ( I am in the same boat, and am thinking now of sending it out to be rebuilt) but knowing that you have an all gear tcase is worth it.
I was always impressed by how good the QT is, but one thought was always in my mind, what if the chain breaks, unlike all other tcase, the QT will stop dead in it's tracks, the chain drives both front and rear so you are going nowhere, that scares me.
Even though on my last outing in my waggy, I broke the transmission case which pretty much gave me the same result, but I will be doing something to prevent that from hapening again.

[Elliott]

The TH400 did come with the D20, before the quadra trac came out. You can still get the adaptor, I believe it's even the same TH400 output shaft, and then Bull Tear makes a billet TH400/D20 adaptor.

[HI-TECH REDNECK]

yep, i got two complete sets.

2 BOP TH400's with the D20 adapters and two D20's.
one of the trannies is said to be good but i don't know if i would trust it. other trans is junk for parts (has no valve body in it). one D20 is good and i think the other one might not be, not sure....i also have one adapter to mate the BOP trans up to a Buick 350.

either way i have enough parts to get a working set up and have some spare parts left in case of any carnage that may occur :rolleyes:

[james1414d]

Moot point, but, a divorced Dana 20 was used in old datsun 4x4's and some van 4x4 conversions.
Any pre 73 th400's will work with the correct AMC adaptor and torque convertor I'd think.

I remember old ford trucks used some sort of divorced Dana (24?) t-case. I wonder if anything interchanges?

[HI-TECH REDNECK]

Moot point, but, a divorced Dana 20 was used in old datsun 4x4's and some van 4x4 conversions.
Any pre 73 th400's will work with the correct AMC adaptor and torque convertor I'd think.

I remember old ford trucks used some sort of divorced Dana (24?) t-case. I wonder if anything interchanges?
interesting. i wonder how the D20 in the datsun's compares to the fsj D20's for strength. i bet those are hard to come by....haha.

[imiceman44]

The TH400 did come with the D20, before the quadra trac came out. You can still get the adaptor, I believe it's even the same TH400 output shaft, and then Bull Tear makes a billet TH400/D20 adaptor.

The AMC th400 came with a D20?
What year?
I know the buick 350 came with a th400 and D20 but then the AMC engine and the th400 came at the same time with the QT, am I wrong in the history was there a year where the AMC th400 and D20 all were together?

[HI-TECH REDNECK]

no you are right. the BOP TH400's came with the D20 and the AMC TH400 came with the QT (from everything i have read). this is what Elliot meant i think, not that there were AMC TH400/D20 combos.

however, i have heard that AMC did some very oddball things on occasion and the "general rules" of what came with what were not ALWAYS adhered to. I'm sure Elliot or someone else will correct me if i am wrong.....

[Mikel]

The AMC th400 came with a D20?
What year?

Pre-QT (1972 to whenever the TH400 was introduced, 66?). Even during QT times, you could order a TH400/D20 combo.

[Elliott]

Prior to the introduction of the quadra trac, and probably even then at first, the TH400 used in the Jeep was the universal or nailhead TH400... it had adaptor rings to mount to the Buick or AMC (Ferrari, Jag, etc.) motors so it's not technically an AMC TH400 but the tailhousings were the same and then all fit the adaptor to the D20. IIRC the tailshaft was even the same on the quadra tracs so all you would need on a "AMC" TH400 is the adaptor to the D20 and you are set.
Somebody correct me if I'm wrong on the tailshaft being the same (same spline count and all) but I think I'm right on that.

[imiceman44]

Prior to the introduction of the quadra trac, and probably even then at first, the TH400 used in the Jeep was the universal or nailhead TH400... it had adaptor rings to mount to the Buick or AMC (Ferrari, Jag, etc.) motors so it's not technically an AMC TH400 but the tailhousings were the same and then all fit the adaptor to the D20. IIRC the tailshaft was even the same on the quadra tracs so all you would need on a "AMC" TH400 is the adaptor to the D20 and you are set.
Somebody correct me if I'm wrong on the tailshaft being the same (same spline count and all) but I think I'm right on that.

The th400 behind the Buick engine has a 32 spline output shaft and it's only 3" stickout, the D20 has an intermediate coupler part of the adapter to mate to that 32 spline output, I believe the actual input on the D20 is a 6 spline.
The AMC th400 output for the QT is a long shaft coarse 10 spline output that goes all the way through the QT and into the Low range unit.

[Elliott]

Ok, so the output shafts are different. He'd be best off to just get an early Jeep TH400 then, and not look for just the adaptor. But if somebody had a tranny they were parting he could swap in the tailshaft and bolt on the adaptor and be good to go... it'd also be a lot cheaper to ship just the parts.

[imiceman44]

Ok, so the output shafts are different. He'd be best off to just get an early Jeep TH400 then, and not look for just the adaptor. But if somebody had a tranny they were parting he could swap in the tailshaft and bolt on the adaptor and be good to go... it'd also be a lot cheaper to ship just the parts.

Well he already has the BOP th400 with the right output, and the adapter, he needs an AMC case or if he already has one all he needs is to tear it down and replace the output shaft, which coincidentally is what he knew, and wanted to avoid, read his first post :thumbsup:

[HI-TECH REDNECK]

yep, i like to think i know whats going on :rolleyes:.....

it was more of i knew how to get the D20 in there, then my buddy mentioned divorced cases and the thought hit me.

"why cant i set up the D20 to run it divorced? i wonder why i have never heard of anyone else doing that?".

to sum it all up if i had looked at the parts laying in the garage i would have figured out really quick that it would be lots more work to do that then tear my trans apart and change the output shafts. but since going out in the garage required getting out of my chair and getting dirty moving parts around, i decided to post it here instead....:D

and yes i have an AMC cased TH400 in my truck, so i just need to get the BOP shaft installed in my AMC case and i have the adapter to bolt the D20 to the trans.

[Elliott]

Well... get busy then. :thumbsup:

[KaiserMan]

AA used to make a divorce mount kit for D20's. I guess they where popular to swap into 2wd mini trucks back in the day.

I would not mind finding one for my J300.

[KaiserMan]

http://i103.photobucket.com/albums/m144/Mattritchie_2006/transfer%20case/P6290002.jpg

If anyone has one for sale, I'd be interested in it.

[mdill]

I think you were on the right track when the thought that this was going to be more trouble that it was worth, then you proceded stright to deep end of the pool.:p
My advice would be to back off on the beer and resulting drunk buddy chear fest talk that always seems to end up badly. (been there done that have the scars to prove it)

im sure someone is going to tell me this is more work then its worth or not going to be durable enough or whatever, but that's OK. i was talking to a buddy tonight and he made the comment about liking divorced transfer cases. that's when the light bulb turned on in my head....

a little while ago i bought a Dana 20 transfer case with the tranny and adapter it came on and shifters. problem is, the trans is a BOP TH400 and i have the AMC TH400. so to put the Dana 20 on my AMC trans i need to change the output shaft in my trans with the one from the BOP trans. this divorced case idea got me thinking. if i mounted it up divorced instead of married, then i can make an intermediate drive shaft and use that as a way of adapting the splines in a way....

so i want to know what you guys think about this. from what little thought i have put into it so far (in the last 15 min only) i figure i need a plate to cap off the end of the t case so it doesn't leak, i can fab into this a mounting system which will help securely hold the case into the truck so it doesn't fall out :eek:. then all i need is some yokes that fit the splines on the output of the trans and the input of the t case and fab them up on a drive shaft.

another benefit to divorce mounting this case i see is the ability to "attempt" to place the case so that i can use my stock drive shafts front and rear, and better clear the tranny bell housing with the front drive shaft by offsetting the case to the passenger side of the truck a little bit.

my future plans for the truck will likely involve drive shaft mods when i do the soa and shackle flip in the back, however im not ready (financially) to do this yet. i would like to get low range in the truck as soon as i can because i have the stuff to do it and then i can run larger then 30" tires and still be able to drive off road. 33's with out low range are really more of a drag than any fun with the muddy hills and rocks we have up here. so if i can get low range in and working, then i can run some 33's or 34's and have the truck still be functional both on and off road. (i have a matched set of 5.38 gears that have been welded to the carriers for the front and rear of my truck, these will go in when i do the soa/shackle flip and larger tires). so 2.0 low range will be plenty low enough i think :D.

im a broke college kid trying to find a job, so money is non existent. however, i do have a CNC class this semester where i could make any plates i may need for this. i don't see any reason this wont work and would be considerably weaker than a married set up provided i build the mounts right. im thinking leaf spring style bushings to mount the case to the frame or cross member whichever i end up doing (or both). my time frame for this project is some time in the next 6 months to a year (basically whenever it gets done is fine with me).

commence discussion :rolleyes:

[HI-TECH REDNECK]

I think you were on the right track when the thought that this was going to be more trouble that it was worth, then you proceded stright to deep end of the pool.:p
My advice would be to back off on the beer and resulting drunk buddy chear fest talk that always seems to end up badly. (been there done that have the scars to prove it) haha, this was a completely sober conversation that planted the idea....not sure if thats a good thing or not but oh well :o

AA used to make a divorce mount kit for D20's. I guess they where popular to swap into 2wd mini trucks back in the day.

I would not mind finding one for my J300. a guy on the local wheeling forum I'm on here in Marquette said that they built a divorced D20 set up in a race truck. said it took too long and too much money to be worth it (and they had access to all the machines needed or payed to have it made). this got me thinking on what it would take to make it divorced and i came up with something similar to the AA conversion.

i didn't make any drawings or anything i just was like, all u need is something to hold that input gear onto the case with and then you can put a yoke or flange on the end of it. problem is, most people don't have the means/need to actually do it.

[Elliott]

Here's a divorced case for you, D23 for passenger side drop:
Napco Spicer 23 transfer case for sale. serial number T136960. worked well when removed. no leaks. call damon 602-620-9667 in Phoenix, Arizona.
Posted: Thu, 11 Dec. 2008 - Expires: Fri, 11 Dec. 2009