i took my truck for a drive the other day and it would not shift all i had was first gear.
it was like i had all 4 gears til it warmed up.
any ideas?

1998 gmc 6.5 turbo 4x4 duelly extended cab

thanks k_nine

 

It's an Auto I assume ?
Put a scanner on it and look for tranny codes. I assume you did the obvious and checked the fluid.

 

ya its a automatic and it stinks real bad

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and it was right up on fluid

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just took the truck for a drive the check engine light came on. but i couldnt get the truck over 40 mph with out it revving up over 3000 rpm, and not pushing it

 

Gotta get the codes...smelt real bad is not a good sign.

 

i have a guy coming on monday with a code reader

 

post em up.

 

i will as soon as i find out

 

I would check output speed sensor on transfer case
I had the same thing happen too me.
On my 1995 chevy 3500 4x4

 

thanks i wil look at that

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ok
had a scanner put on my truck to read any codes, but the scanner would not connect to the computer. it wasnt a cheap scanner this guy is a class A mechic. called another garage and they said there could be a broken wire some where.
so i have a wire diagram coming to look for a broken wire.
not sure what to do now million wires to go though.
any ideas let me know
thanks
k_nne

 

If you can't connect to the ecm I'd say that is part of your problem.