GMC 1996 Sonoma Owner's Manual page 330

Long Trip/Highway Maintenance Schedule
- -
50,000 Miles (83 000 km)
0
Change automatic transmission fluid and
filter if the vehicle
is mainly
driven under
one or more of these conditions:
-
In heavy city traffic where the outside
temperature regularly reaches 90°F
(32°C) or higher.
-
In hilly or mountainous terrain.
-
When doing frequent trailer towing.
-
Uses such as found in taxi, police or
delivery service.
I f you do not
use
your vehicle under
m y
o f
these conditions, tlze,fZuicl and-filter- do not
require chnnging.
Manual transmission fluid doesn't require change.
DATE ACTUAL MILEAGE SERVICED B Y
7-38