TH350 won't shift out of 1st...

[blazerpro79]

Hey everyone, this morning when I left my house for work, my truck was not shifting from 1st. Its a th350 with an np203. It shifts fine from park to rev, and d1, and n. I manually moved the column shifter to d2 but it didnt make a difference.

Yesterday I changed my tie rod end and valve cover gaskets. I test droev it when I finished the install and it ran great. Then when I got home, I popped the hood, double checked it all, and put the air filter back on.

My guess is I knocked something loose when I replaced my air filter after the test drive. I didnt purposely disconnect any vacuum lines and quickly checked this morning to see if I could see any loose ones, but didn't.

Does anyone have any spots to start at to start diagnosing this problem? Thanks.
-Mark

 

[sweetk30]

back of intake just behind carb pad. there is a port for vac to the vac modulator on tranny. if that came off at intake or tranny end it will shift vary late and also hard. there is a short rubber hose on each end check them for cracks.

 

[Thunder]

X2 on above post. Check the vac line from intake to the Vac modulator on the trans.

 

[blazerpro79]

Yeah it was the line coming from the back of the intake to the trans vac modulator. The thing was, the hardline had cracked somewhere, so it was just a coincidence it happened when it did. Easy enough fix though, I appreciate the help guys. Thanks.

 

[Big Blzn]

back of intake just behind carb pad. there is a port for vac to the vac modulator on tranny. if that came off at intake or tranny end it will shift vary late and also hard. there is a short rubber hose on each end check them for cracks.

Cool. I just learned something today. Never knew what that hose was for. Now I can call it a day.