Hello, I have a 2000 GMC Sonoma and when I'm driving on the freeway for about an hour or more the truck will down shift from overdrive to third. When this happens I'm usually going about 75 so this will cause the truck to redline. The only thing I've done to solve the problem is change the transmission fluid. Any answers will be greatly appreciated.
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Transmission shifting from overdrive to third
- Thread starter sgarteiz
- Start date
Molson02536
New member
Hello, I have a 2000 GMC Sonoma and when I'm driving on the freeway for about an hour or more the truck will down shift from overdrive to third. When this happens I'm usually going about 75 so this will cause the truck to redline. The only thing I've done to solve the problem is change the transmission fluid. Any answers will be greatly appreciated.
Sounds like your transmission line pressure is dropping. You can adjust your EPC valve, but your going to have to drop the transmission oil pan again.
The other thing you can try to do is replace the servo with Corvette servo's. There no more then $45.00 dealer and less on E-Bay, it take about less then an hour to do with simple tools if you don't have a lift.
keep us posted and be safe
Molson02536