Upshifts normally until it suddenly downshifts

1990 DODGE CARAVAN
270,000 MILES • 4 CYL • 2WD • AUTOMATIC
Avatar
JAY STERN
  • MEMBER
  • 1 POST
(Caravan with just front seats). Vehicle starts, moves in all gears. Upshifts normally until it suddenly downshifts. Turn off engine. Restart and shifts normally for few minutes, then downshifts again. Is this a solenoid problem or are the transmission bands gone and tranny must be rebuilt?
Jul 18, 2021 at 5:16 AM
Advertisement
Avatar
ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
Good morning,

This sounds like a valve body issue within the transmission.

https://www.2carpros.com/articles/automatic-transmission-problems

I would start by changing the fluid and filter. Pay close attention to the bottom of the pan and see if there is any metal in the pan. If there is metal in the pan, then most likely you will be talking about a rebuild or replacement.

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Roy

Image (Click to enlarge)
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Jul 18, 2021 at 9:10 PM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.