Transfer case trouble or transmission

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rpcraft

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If it were diesel I think but then again I could be wrong.

I think that is right, if only because K5 Cucv's could have a TH400 option but only because it had the disel engines
 

hatzie

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I thought 3/4 ton Burbs got them, and the halves did not.

I think you're correct that it's not just the diesels but I'll need to consult the parts books.

***EDIT***
Diesels got the optional M40 trans for all years.
1987 1/2, 3/4, & 1 ton 5.0L, 5.7L, 7.4L & Diesel
1988 3/4 & 1 ton 5.7L, Diesel, & 7.4L
1989 3/4 & 1 ton 5.7L, Diesel, & 7.4L
1990 3/4 & 1 ton 5.7L, Diesel, & 7.4L

1991 ???
 
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1987 GMC Jimmy

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I think you're correct that it's not just the diesels but I'll need to consult the parts books.

Sounds good. I tried to confirm with GM Heritage Center, but I got nowhere.
 

b26j

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I might look into the linkage, I noticed that the shifter for the transfer case has some free play before it will engage, I don't remember if it was always like that
 

rpcraft

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I can't recall what all slack there can be on the Np208 but if it has been shifted around there may be some wear on the end of the linkages. I know the shifter mechanism was nothing like the earlier T cases.
 

b26j

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I took it on a short drive today and it seemed to shift and drive pretty good, I took over to a friend who knows more about the drive train then I do and of course it didn't act up once, then after I left his place and came to a stop sign it seemed like it was in neutral again, I shifted from 2high down to 4low then back into 2high then it worked fine again
 

Honky Kong jr

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It’s gotta be in the transfer case
 

b26j

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I may take the transfer case out and compare it to one that a friend has in his shop, while I was under the suburban checking things over I saw what looks like a slight crack down the side of the transfer case but not for sure if it is a crack, I'm going to get it up on a hoist and hope to be able to get a better look
 

rpcraft

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I agree. Might be time for a rebuild or replacement.
 

b26j

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I'm taking it to a shop that works on transmissions and they are going to check everything over, I appreciate everyone's input and I will update as soon as I know what is wrong with it, I hope it is nothing to major
 

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