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Round pattern 205

Hogback Fabrication

Hogback Fabrication

1 ton status
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What trucks do they come in?

AFAIK it seems like they are behind 1 ton trucks with the SM465's and TH400's from the 80's.

Should they really be that hard to find? I've been looking for a while and have posted several wanted ads and still can't find one :confused:
 
I thought the figure 8 was the desirable one.
Ive got an extra 205 with a th350 adapter bolted to it. I think it has a 6 hole bolt circle.
 
I think i've mentioned this to you before, i have a bare round pattern case just sitting here.
 
85-91 1 ton GM's had NP205 with the long 32 spline input and the circular 6 pattern. Not sure about the 1/2, 3/4 ton trucks.
 
I've got several, might sell one as I need to pick up some stuff in Denver soon.
How do you need it equipped? Do you need a bare case? 32 spline front? Slip yoke eliminator rear? Need an adapter?
Jimbo
 
No 1/2's or 3/4's came with 205's after (or awhile before I suppose) 1984.

It's round every year after that. 4L80E as well as TH400 and 465.

Only oddball was the 1991 without speedometer cable, but that's a + IMO. :)

I can't recall the specifics (I think it may have been earlier than '85 on some?), but the adapter is longer on the '85+ ones, which requires a different shifter handle as well, if sticking with stock.
 
I've been looking for one for a while as well Chris. Not the easiest thing to find for some reason. I was searching the pull-n-save once a week or so, but it isn't as cheap to drive across town anymore. If you don't grab one of these ones I might be tempted. I have the 32 spline input and front output just needed the rest to do a build. It isn't as hard to find a figure 8 pattern guy for the rest of the parts if you/I can only get a case.
 
Recently, I had been looking for some time and finally found a NOS housing (empty case) and bought it. Then I started searching for the input gear (which is specific to the round pattern case). Finally found it. Now, I can gut any GM 205 to build the round pattern case I need.
It seems that recently these have become much harder to find. About three years ago, I was casually looking around and found a few--bought one--then sold it thinking I could find another without much effort--bwahahah, D'oh!! Maybe it's just a cyclical thing. When you need a D60 there are none to be found. When you don't need one they are practically growing on trees.
 
GM's transition to the "round" case solved a number of recurring problems;

A) eliminated the coarse spline spud shafts and breakage prone coupler in the SM465/NP205 combination

A)1) Allowed GM to produce one model of 4X4 SM465 transmission instead of two
(long 32 spline output coupled directly to NP208, NP205, and later NP241, without
use of wear prone couplers)

B) greatly reduced the frequency of broken transmission to transfer case adapters due to excessive leverage. I've never seen or heard of a broken "short" adapter--many with stripped threads, but no broken feet. Can't count the number of "tall" adapters I've seen, let alone heard about with broken feet, or cracked/broken in between the tranny and transfer case.

C) Allowed GM to use their heads, and produce one transfer case for the 1 Ton pickup line which would interchange throughout the line, regardless of transmission (Ford had been doing this for years with the 205)

In short, the round pattern transfer case is no stronger than a figure eight, but the necessary adapter is much stronger.


Jimbo
 
Jimbo* said:
In short, the round pattern transfer case is no stronger than a figure eight, but the necessary adapter is much stronger.


Jimbo
Click to expand...


Huh? I have a 32 spline 465 and 205 adapter sitting at the shop right now and I am 99.9% sure the adapter is as long or longer than an equivalent 10 spline piece. Are the later adapters beefier or am I missing another part of the argument?
 
mikey_d05 said:
Huh? I have a 32 spline 465 and 205 adapter sitting at the shop right now and I am 99.9% sure the adapter is as long or longer than an equivalent 10 spline piece. Are the later adapters beefier or am I missing another part of the argument?
Click to expand...

B) greatly reduced the frequency of broken transmission to transfer case adapters due to excessive leverage. I've never seen or heard of a broken "short" adapter--many with stripped threads, but no broken feet. Can't count the number of "tall" adapters I've seen, let alone heard about with broken feet, or cracked/broken in between the tranny and transfer case.


You are correct that the later adapter is longer (8" vs. 10"), but the argument was centered around the height of the adapter(s).

Jimbo
 
Does anybody know if the internals are the same between 205's?

I have all the gears, bearings, etc. from a Ford 205. Can I put those in a Chevy 205 case?
 
Except for the front output, which are interchangeable, and the input gear I believe the internals are the same. Those two pieces are different but you can use them. Only oddball in the bunch are the synchronized front output 205's found in some GM trucks with the dana 60 and auto-hubs. Let me know whose your picking up, as I need one to.
 
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