A442F doesn't want to shift up when cold

Joined
Apr 29, 2011
Messages
95
Location
Boulder, Utah
I have the A442F fully hydro auto tranny in my 1990 HDJ80. When the tranny is cold it doesn't want to shift up gears while in D, but it will shift when I run through them manually using the shifter. After it warms up for a minute or two this goes away and it shifts just fine for hours on end. Does anyone have a clue what the problem might be? I'm curious if a valve body upgrade might fix this but Rodney's folks haven't been remotely helpful in figuring out my actual problem.
 
Joined
Feb 4, 2015
Messages
2,532
jellis, You may want to get out your service manual so you can test the shift solenoids inside/under the trans pan to make sure they are working correctly. With high miles on this transmission you can have solenoids fail causing the transmission to experience shifting problems.
 
Joined
Apr 29, 2011
Messages
95
Location
Boulder, Utah
Fully hydro, no solenoids to check! The FSM for my tranny has you measuring pressure at various RPMs--I could do this but seeing as it works fine 99.9% of the time this seems to be not the problem.
 
Joined
Feb 4, 2015
Messages
2,532
I see what the problem is now, at the top of this page you listed you're question as a A442F trans, but in your by line you list it as a A442, so that's the reason why i said to check your solenoids, the A442F uses solenoids as you can see in the photo below.

1605071888956.png
 
Last edited:

Users who are viewing this thread

Top Bottom