Dana 20...TH400 adapter or not?

[Bigums]

I'm pretty sure the deal on the TH400/D20 behind the AMC 360 was that it was the 'nailhead' Buick-patterned TH400 and that an adapter ring was used for the AMC engines. I know that was the case for mating them to the Buick 350.

More intelligent people will reply and correct or support my claim as necessary, I'm sure.

[J20 project]

Ok, Here's how it went.
65-68: 327 rambler/2in adapter/nailhead Buick th400/2nd adapter/D20
69-71: 350 Buick/2in adapter/nailhead Buick th400/2nd adapter/D20
72-731/2: 360 AMC/2in adapter/nailhead Buick th400/2nd adapter/D20
73 1/2-79: 360 & 401 AMC: AMC specific th400/QT adapter/QT trans case.
80-91: 360 AMC/torqueflite 727/various new process tcases.
There was never a jeep application involving any chevy or BOP th400's.
Also, both the 327 and 360 apps w/ the nailhead case involved a 3/4in crank spacer. I just don't remember if the 350 Buick needed one or not.
Also, 65-73 1/2 used a (32?) fine splined output shaft on the th400 for the D20 set up.
73 1/2-79 Qt cased jeeps used a coarse spline tailshaft.
Chevy swaps are done easily if a chevy th400 case is used.
I'm running a 76 model th400 w/ the older tailshaft and D20 transfer case.
J20 project

[porkchop]

Hmmmmm... The 70 wag that is in front of my house has a Chevy TH400/D20 that is the original tranny. It had the buick 350 and a spacer. the tranny is a Chevy TH400. Where did you get that info from?

[Bigums]

Interesting PC. I'd be interested to get to the bottom of this.

Of course, the way AMC did things, everybody could be right...

[Hump]

Sounds like i've opened a whole can of worms. So I could use an older th400 that would have the correct output shaft, but I would have to use and adapter at the engine?

Ok, J20 mentioned something about a crank spacer for the 360's. I have a 401 would that need one too? Is it a slide on deal, or does that intail more major disassembly?

I'm kind of leaning towards changing the output shaft in the tranny I have so it doesn't mess up the location of the crossmember. I do have one I could practice on, but the big deal is that I don't have a large "clean" space to do it in. Just called and it looks like $400 to have it rebuilt, and they will just swap the shaft as part of the regular rebuild price.

Pete, how much do you want for that shaft?

[Hump]

btt

[gsmikie]

hey its no big deal just tell me what you want to bolt the th400 to and i will handel it rebuilt of course hey maybe another road trip ?Mmmmmmm

[J20 project]

PC, Just for the heck of it go take a look at where the starter would have mounted on the trans bellhousing on the 70. If it's the original tranny then it will be on the drivers side. I mean the trans bellhousing, not where the adapter mounts the starter. If it mounts any other way, it is not the original tranny or somehow someone at Jeep had a really bad day and hybrided a chevy case w/ a one of a kind 2in adapter to the Buick.
J20

[J20 project]

Hump, Yes for the 401 and the older trans you will need the 2in adapter to mate to the th400 and the crank spacer on the engine. If you don't then the torque converter will not engage into the tranny oil pump once it's all bolted to the engine and flexplate. J20

[porkchop]

I will go out and check it in the morning. I can also get some pics of it.

[Hump]

CJM, please let me know what you want for that shaft.

Just to clarify. I hope nobody took my comments to mean that I felt I got screwed by the guy who sold me the dana 20. He sold me exactly what I wanted and what he said he was selling. I just didn't realize that it wouldn't bolt up to my th400.

I've got a line on a tranny rebuild, the matching tranny for my dana 20, and a whole rebuilt combo with all the necessary parts. So I just have to figure out which is going to be most cost effective. Thanks for all your guys help.

[Hump]

btt

[J20 project]

Hey Porkchop, Did your ever figure out which tranny you had in your 70?
J20

[porkchop]

No I forgot all about it. It is not my 70. It is a freinds, Gremlins. I will look when I get home tonight.

[Mike D]

Originally posted by porkchop:
I will go out and check it in the morning. I can also get some pics of it.

And if you got the adapter from the "jeep"th400 to the dana20, you can use a chevy 2wd th400 with a chevy motor...i did, with a 283.....but the six bolt patern on the chevy was slightly turned counter clockwise than the "jeep"th400(hydromatic bought from chevy for jeep)...but who cares!!!!!