Np205

[Tippin Spotted Cow]

Alright, any bit of intelligence on this subject would be much appreciated:



The stock NP205 transfer case that would have come with the Getrag is the 29 spline with the "racetrack" 8 bolt pattern input side. This is a rare case and fetches a pretty penny. So I've heard that a 27 spline case, or a 31 spline, i believe, are a direct swap out for the 29 spline shaft. The 23 spline I have with my auto is a smaller bearing and the case needs to be machined to fit a 29 spline. I've found ford a chevy NP205s for $100-$200 and I believe some of them have the right size bearing. What I need to know is what chevy or ford cases would have the right bolt pattern and the bigger bearing so I could make it fit my truck? The rare 29 spline case goes for $600 or more, and would love to pocket the extra $400-$500 if possible. Any help would be much appreciated.

 

[Ctdchris]

When my friend did his Cummins swap into his '89 k30 he used his stock 205 that was behind an sm465, and swapped the inputs. I'm not sure which input it was to begin with, but I'll ask him and report back. He did no machining on it, but had to use an adapter that he found somewhere to replace the cast adapter in a first gen.



Why are you replacing the case? can it not be rebuilt? or is this for a project of some sort?



Chris

 

[Tippin Spotted Cow]

I have an auto transmission right now (23 spline case), and I'm swapping in a Getrag (29 spline). The 23 spline case needs to be machined to fit a 29 spline shaft. I can't have that much down time on my truck. I need a case ready to go when I swap the trannies.

 

[Joseph Donnelly]

I have heard that the bearing retainer is different but the case with a smaller hole could be bored out. You would be best served by contacting someone like Standard Transmission & Gear in Fort Worth (Standard Transmission & Gear, 800-std-tran) for information and parts.

 

[Tippin Spotted Cow]

Chris, your buddy's tcase for a SM465 would have had the 32 spline... Upon further investigation, the 29, 31, and 32 all have interchangeable bearings, while the 10, 23 and 27 all have the smaller bearing, requiring the case to be machined to accept the larger shafts.



As I said, the SM465 had the 32, which will work. As you stated though, the SM465 bolted to a tcase with a different bolt pattern. The SM465 case has the 6 bolt round pattern, while the Getrag was originally used in front of a t-case with the "racetrack" 8 bolt pattern. The only other transfer case that fits the profile of the large bearing and the 8 bolt pattern would be off a turbo 400 transmission, but that would make it an old case. Chris, can you ask your buddy where he got an adaptor to go from the 6 bolt transfer case to the back of the Getrag? I can find a SM465 case pretty easy and dirt cheap, and I'd love to do it that way.

 

[Mopar_Tim]

the problem your having finding the case is b/c your looking at cases where people know what they are



i picked up my 29 spline case for like 250 plus shipping



check online junk yards

 

[Ctdchris]

Chris, your buddy's tcase for a SM465 would have had the 32 spline... Upon further investigation, the 29, 31, and 32 all have interchangeable bearings, while the 10, 23 and 27 all have the smaller bearing, requiring the case to be machined to accept the larger shafts.



As I said, the SM465 had the 32, which will work. As you stated though, the SM465 bolted to a tcase with a different bolt pattern. The SM465 case has the 6 bolt round pattern, while the Getrag was originally used in front of a t-case with the "racetrack" 8 bolt pattern. The only other transfer case that fits the profile of the large bearing and the 8 bolt pattern would be off a turbo 400 transmission, but that would make it an old case. Chris, can you ask your buddy where he got an adaptor to go from the 6 bolt transfer case to the back of the Getrag? I can find a SM465 case pretty easy and dirt cheap, and I'd love to do it that way.

Its kind of funny... I was with him when he found the adapter. We stopped by a friend of ours shop to look at one of his Cummins builds and we found the adapter laying in his shop yard. He said he had no idea why it was there and that my friend could have it. All i know is it was aluminum. I will ask him what it came out of though.



Chris