One problem related to transmission slip out of gear has been reported for the 1999 Dodge Avenger. The most recently reported issues are listed below.
Transmission failed to shift out of first gear properly and downshifted harshly, to the point I cringed at the sound. Upon replacing original tires local mechanic notified me of a worn wheel bearing at right front being ase certified myself I inspected the part and came to the same conclusion.