Operation CHARM: Car repair manuals for everyone.

Slipping 1-2 Upshift

1. Low fluid pressure.

2. Missing sealing ball in valve body.

3. Leaking second clutch piston seals.

4. Second clutch piston centrifugal ball stuck open.

5. Second clutch piston cracked or broken.

6. Second clutch plates worn.

7. Leaking oil pump hub sealing rings.