'77 lebaron trans problems

i have a 1977 lebaron with a 2-bbl leanburn 318 with a 3 speed auto
trans (not sure what kind of trans)


anyway, i have two problems with it:

1) it will not downshift/kickdown when you depress the gas pedal all
the way down

and

2) under minor acceleration it will shift from 1st to 2nd, then back to
1st and back up to 2nd really fast. the 2nd to 3rd shift seems totally
normal. under hard acceleration, the 1st to 2nd shift is normal.

i replaced the neutral safety switch for the hell of it and it didnt do
anything, not that i was expecting it to...

any ideas on what it might be? anything i can try before taking it to a
transmission shop and paying an arm and a leg?

any help is great help

thanks
-glen

 

A-904, I'd bet

Throttle valve linkage is maladjusted.

"Shuttle shifting" could be caused by the linkage maladjustment, but
I've never seen it like that. When's the last time the fluid was
changed in this thing, and has the valve body ever been pulled and
cleaned? Probably not.