shifting issue

[76_gmc]

Stopped at an intersection, green light go....starts off like normal but won't automatically go up the gears. Stays in first. Auto transmission, fluid level good. linkage good.

only thing i know is that the np208 has been leaking out the output seal and thats another story, if anyone can lead me in the right direction in getting one and replacing it, i have a slip yoke too.

but the main issue....transmission won't shift up, i don't hear anything funny, smell anything....??????

 

[76_gmc]

I got it!!! the dang transmission governor spline was worn....

 

[99GmcClassic]

Replace that t-case seal soon. If that fluid gets low the chain will stretch and eventually snap. Seal is cheap like 14.50 from the dealer, be careful when u remove the old one not to crack the tailshaft.