'94 850 Auto Gearbox question

The auto gearbox on my 1994 Volvo 850 20v GLT gets lazy when it's been
standing for a few days; it doesn't want to shift up when I drive away,
though when I temporarily move the gear lever to the "3" position the
box shifts up as normal, and when I then change back to the normal Drive
position, the problem stays gone, regardless of how briefly it was in
"3" for. If I don't do anything and just keep driving, eventually, the
box does begin to work normally.

I have checked the oil level carefully as per my Haynes service manual
instructions. Is it worth changing the oiil (although the manual says I
shouldn't need to unless it is particularly burnt)? As putting it in "3"
solves the problem, isn't this more likely to be some kind of
electronics issue?

Many thanks for any advice.

 

ATF should be changed on regular intervals- do some research on your
car to see what folks recommend. It depends in teh type of driving,
but I would think that every 30,000 - 40,000 would be a good start.
Change the filter as well. As the joke goes:

PATIENT: "But doctor- that can't help!"
DOCTOR: "It couldn't hurt!"

Your shifting problems sound like a PNP switch. Do you "cold shift"
though the gears rapidly once in a while?- That is, with the engine
off and the reverse lockout button depressed, shift from one end of
the pattern to the other about 15-20 times rapidly. This helps keep
the PNP switch clean and extend its life a bit.

__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"

 

Thanks for the great advice and tips. I appreciate it.