help me out 1996 engine in a 91 gmc c1500

[gkrodgers]

hi i’m 15 and have been working on my truck for quite a while now and i’ve found myself in a position where i don’t know where to go

my sierra has a newer engine and has been sitting for 5 or so years the transmission decided that it with run and drive off startup but once you stop at a sign or light it will not go just will rev to the limiter also the shifter will not go in any other gear unless the truck is turned off and had a second to cool down. i believe its a th400 but dose anyone know what could possibly be wrong?

 

[Erik the Awful]

If your truck is a '91, it came with the 4L60 (700R4). The TH400s only came in the heavier trucks. That doesn't mean it hasn't been swapped, though. Is the pan a rectangle (4L60), or is it kinda shaped like Indiana (TH400)?

First, check to make sure your transmission fluid level is good.

Second, check to make sure your shifter linkage isn't hitting anything. I put headers on my truck and every time I went full-throttle the header would knock the linkage into neutral.

If you have the 4L60, it has a TV cable, and you better get schooled quick before you dork with anything. A bad TV cable adjustment will not cause your problems, but it will definitely burn the transmission up in a matter of minutes.

 

[gkrodgers]

If your truck is a '91, it came with the 4L60 (700R4). The TH400s only came in the heavier trucks. That doesn't mean it hasn't been swapped, though. Is the pan a rectangle (4L60), or is it kinda shaped like Indiana (TH400)?

First, check to make sure your transmission fluid level is good.

Second, check to make sure your shifter linkage isn't hitting anything. I put headers on my truck and every time I went full-throttle the header would knock the linkage into neutral.

If you have the 4L60, it has a TV cable, and you better get schooled quick before you dork with anything. A bad TV cable adjustment will not cause your problems, but it will definitely burn the transmission up in a matter of minutes.

thanks for the advice i’m not sure off the top of my head what shape the transmission is but i’ll check the next time im at the shop thanks for letting me know about the tv cable.