350 t problems

[nstarry]

my van is going in and out of gear it will go in for a minute and then drop out you can get it up to overdrive then it holds is this the modulater or is it clogged any one know
the gears are solid when it is in you can light up the tires

mid 80s GM 1/2 ton 350/350t 2wd van

 

[motofool]

check fluid level lately?

 

[nstarry]

yep its full /forums/images/graemlins/thumb.gif

 

[motofool]

ive heard a shift kit can solve those problems might of been only on th400's thou.

 

[big jimmy 91]

Sounds like there is an internal leak in the tranny that allows the pressure to drop enough to let it drop out of gear
This happened to me with a 77 Gypsy van
Its like it shifts into neutral when you stop , then when you hit the throttle it revs up and boom it drops into gear like you are doing a neutral drop /forums/images/graemlins/eek.gif
This could be whats happening with your van /forums/images/graemlins/dunno.gif

 

[nstarry]

this is the other way it starts out then drops out then gos in then comes out and you can do that all the way threw the gears all the way to third then it will hold in third /forums/images/graemlins/dunno.gif