New M1028 owner with 208 question

[fitz]

I've owned a bunch of 73-87 chevys but my M1028 is my first cucv. Just wondered why GM installed a 208 transfer case instead of a 205. I've owned a few 1 tons and they all has 205's in them.
Were the 208's used to save weight incase they had to be replaced in the field?.
I also noticed that it uses a 203/205 flat style crossmember, not the same 208 crossmember found on civilian trucks.
Thanks,
Fitz.

 

[woopyass]

From what I understand, they used the 208 for two reasons, cost and the deeper 4low gear ratio.

 

[SPECIALTYLC]

The 208 was used because of the higher ratio in low range. 2.48 versus 1.96

 

[fitz]

Thanks guys, any clues about the crossmember?

 

[4bogginchevys]

just curious if someone can clear this up...I thought the 208 had a 2.72:1 low ratio?

 

[Recovry4x4]

New Process 205 has 1.96 to 1 and the New Process 208 has 2.61 to 1 low range. The M1028A1 and M1031 both had New Process 205 cases in them for future reference.

 

[fitz]

thanks

 

[dieselpony]

I also noticed that it uses a 203/205 flat style crossmember, not the same 208 crossmember found on civilian trucks.
Thanks,
Fitz.

I recently changed a NP208 to a NP205 on my M1008. The 205 uses the short round adapter, so my flat crossmember sits to low. Not so many civilian K30's with the W-shaped NP205 crossmember in my part of the world, so I ended up using 2 extra rubber "blocks" (don't know how to call it) for the right height.

Are you sure about the civilian w-shape crossmember on 208 trucks? If so, I could use one from a civilian K5.

I' still didn't test drive the truck, so I'm not sure if my "double rubber construction" really works.

Walter

 

[OLDCHEV4X4]

I've seen the flat and W style cross member's on 208 equipped Chevy's.

 

[acmunro]

I'll second that OLDCHEV4X4 I have civi trucks K-20 's equipped with the NP208 transfercase using both styles of cross members.

 

[POOR WHITE BOY]

All chevy 4x4 trucks from 1973 thru 1984 used the flat type crossmember and tall transfercase adapter. Cucv trucks use the same thru 1987 . Civilian models 1985 thru 1991 use the w shaped or zigzag type crossmember and the hourglass type transfercase adapter.

 

[acmunro]

POOR WHITE BOY does that hold true with the NP 205 also ? Thanks in advance.

 

[POOR WHITE BOY]

Yes 205 and the 208 /241 use the same crossmember provided you use the correct t case adapter. With the 85 thru 91 models they used a w shaped crossmember and they had a zigzag shaped crossmember - the difference being trucks with a diesel engine - had true dual exhaust and used a little different shaped crossmember

 

[acmunro]

Thanks, I was always looking for the rhyme or reason behind the cross member differences. Is one style better than the other one ?

 

[OLDCHEV4X4]

I preffer the flat one for better ground clearance. And I think its a little stronger too.

 

[POOR WHITE BOY]

I agree - the flat one gives you more ground clearance , also more room for dual exhaust but i think the newer style -85 thur 91 has a shorter/stronger t case adapter