203/205 better option over an atlas?

[Cody]

Why does it strike me strange that I wouldn't need any expensive adapter to bolt an atlas to my less common 46 RH ZJ tranny but the extremely common th400 tranny requires some crazy adapter?

Even so, unless the adapter cost 1000, 2800 is way too high for an atlas.

Cody

 

[mbryson]

As I understand it, you run a GM-style 32 spline input in the Ford 205. I'm not sure what the adapter came from, but maybe there was a GM 205 with the round bolt pattern? Bryson knows the details, as well as all those parts for sale in the classifieds here.

Yes there is, but they're kinda rare. mid-Late '80s vehicles with T400s. I wonder if the 208/241 adapter is the same as the 205?

 

[I Lean]

Why does it strike me strange that I wouldn't need any expensive adapter to bolt an atlas to my less common 46 RH ZJ tranny but the extremely common th400 tranny requires some crazy adapter?

Even so, unless the adapter cost 1000, 2800 is way too high for an atlas.

Cody

It's all in the bolt pattern--since your 46RH came with an NP23whatnot it was already correct. The adapter for the TH400 is one of the cheapest though, as I recall I paid under $200 for mine. It's just a plate to adapt the bolt pattern on the tailhousing, and the output shaft of the tranny slips directly into the input of the Tcase.

 

[I Lean]

Yes there is, but they're kinda rare. mid-Late '80s vehicles with T400s. I wonder if the 208/241 adapter is the same as the 205?

Should be similar enough. I know you can use that 208 adapter for a D300/Atlas, but you can only use 5 of the 6 holes IIRC. It's also longer than the small "plate adapter" option, since it uses a spud shaft. (that may or may not be a problem, depends on if you're trying to save every inch of space for rear driveshaft length or not)

 

[Tacoma]

Hmm. I believe it is different than the 208/241... for some reason I think I checked, since I had one laying around. OH! maybe I still have that!

If I do, I'll compare the two. For some reason I'm thinking the bolt patterns are different. I can check the Ford/Chevy interchange as well, there is a Ford 205 here I am robbing the front output from. (32spl, woo hoo)

I'll also check the 46rh fit... I'm going to be using a Dodge 205 on the Cummins, and it looks to me like it is the MANUAL Chevy pattern, with a huge, bowl-like Dodge adapter on it.

my parts piles might be useful! How happy I'd be.

 

[78mitsu]

Having done this conversion... and hunted for cases I found there are 4 different bolt patterns on the 205
gm/dodge - racetrack
gm(np) 6 round (bolt holes are not evenly spaced)
ford - 6 round (different from chevy by)
dodge 6 round ( different from chevy by)

the 203 pre 85 has it's own "special" bolt pattern, after 85, they're 5 round.
I re-drilled the face of the 208 so it would fit the 5 round on my nv4500 - It splines right up no adapter (the adapter is integral to the trans I guess but...)

the 208 always has the 6 round pattern.

The 6 round isn't symetrical or evenly spaced, dodge, chevy and ford all use a rotation of the pattern. it's always the same, bit it is clocked f-c ~90* c-D~45* so if you were to mount a ford tcase to a chevy trans it would clock it so the front output shaft was sticking strait up (assuming of course everything else matched) it's the same with all the NP case, which is why internals directly interchange between a given series of tcase, but the cases are model specific - or an adapter ring that shifts the clocking is used.

hope that helps.

 

[Tacoma]

There are post-85 203's??????????????

well that settles that then LOL Thanks for the post!

 

[78mitsu]

There are post-85 203's??????????????

well that settles that then LOL Thanks for the post!

I must have been groggy, no, they stopped production of the 203 in 79 - in 80 it was replaced with the 208 the post 85 is for the 205 they changed from the racetrack to the 6 round in 86.

 

[Tacoma]

Just keeping you on your toes.

 

[78mitsu]

10-4

 

[harkinoff]

Love my 203 205 doubler. The only issue I have is the weight. I use a comealong off the cage to install it. I run the ford front 32 spline output in my chevy case. It is triple sticked and shifts way easy. I'm 106 wheelbase and have no issues on drivelines. I had the 205 clocked 4" to have a flat and level case setup. Stuffed way sweet under the scout.
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