Cracked NP-208

[leegrady]

I have a '81 GMC k2500 (long bed) with a four speed manual trans. The NP-208 is cracked and it seems it's easier to find these transfer cases mated with automatics rather than my four speed top loader.
How hard would it be to change the parts over so the automatic mated t-case will bolt up with the manual trans? I'm thinking the t-case input shaft will need to be swapped. I'm good with trannies, but any skinny on the subject will be greatly appreciated before I take a sack lunch to the bone yard.

[mod58]

If you find one from an auto,I would just swapout the manual inturnals,you will have to completly disasemble to change the input shaft anyway,so put your guts in the auto case!!

[leegrady]

Yeah, that's what I think too. Thanks for the help. Now I'll switch gears here 'cause I'm wondering about running stronger 205 or even a 203. So I question whether or not one of these would bolt to my four speed and if so is the front axle output on these t-cases on the passenger side like my 208?

[mod58]

I would go with a 205,they are just about bullit proof.I would stay away from the 203,unless you want to run a dubbler.You would need one from a manual trans say a sm465.(10 spline)input. Also you will need the adapter that goe's between the trans and the case and the shifter.also the hole in the trans hump is in a different spot so you will have to adress that also.

[72lb4x4]

I think 80s Dodges used an NP208 with the shaft on the right so you might have a look or check to see if the case will work from one...

[Burlinator]

Originally Posted by leegrady

Yeah, that's what I think too. Thanks for the help. Now I'll switch gears here 'cause I'm wondering about running stronger 205 or even a 203. So I question whether or not one of these would bolt to my four speed and if so is the front axle output on these t-cases on the passenger side like my 208?

the 465 that came with a 208 has a much longer output shaft, older 4 speeds had the 10 slpline output and a figure 8 bolt pattern, the newer style has 32 spline output and a round bolt pattern

I run the old syle 465/205 combo
I have both the 208 style and 205 4 speeds, I'll try and get you a pic of the differences

[mod58]

Your sm465 should have a 10 spline output.71 to 85 99% of the time had a 10 spline,Some 86 an up sm465 had a 32 spline with either a 2' or 3 5/8 output shaft.On both cases the adapter housing was 4 3/8 long,86 and up had a 6 bolt round pattern on the adapter housing.

[rcbildr]

Originally Posted by Burlinator

the 465 that came with a 208 has a much longer output shaft, older 4 speeds had the 10 slpline output and a figure 8 bolt pattern, the newer style has 32 spline output and a round bolt pattern

I run the old syle 465/205 combo
I have both the 208 style and 205 4 speeds, I'll try and get you a pic of the differences

The 32 spline sm-465 with the t-case adapter bolted to it is very close to the same length an automatic tranny. My Burb originally came with a 700R4 and I swapped in a 32 spline sm-465 and I did not have to modify my driveshafts. I got lucky when I converted it back to a TH-400 too...I didn't have to modify my driveshafts either.

[leegrady]

Thanks for all the info'. Think what I'll do is replace the cracked 208 with a completely different unit, or change the guts over to a good case. Run the truck, and begin to stock pile 205 parts for an eventual conversion to these stronger units. Again, thanks for the help. But it's not over yet. Keep the comments, and info' coming. If we can't fix it it an't broke!

[Burlinator]

sm465 with "long" 32 spline output shaft for np208






sm465 with "short" 10 spline output for np205




coupler for "short" 10 spline application, this goes onto the trans output/transfercase input shafts (inside the adapter)




if you want some measurements just let me know and I'll try and get them for you

[leegrady]

The photos are great. Very helpful. Now I know that the thing to do is find a sm465 mated to a NP-205, to make the conversion. Can't tell you how much I appreciate the knowledge.