In today’s video, I go through a full refresh on the Mazda automatic transmission — replacing every major seal, gasket, and the internal filter. This is a common service for these aging B-Series trucks, and it can fix leaks, shifting issues, and help extend the life of your transmission. What I cover in this video:
- Removing the transmission pan
- Replacing the transmission filter
- Installing new gaskets and seals
- Cleaning sealing surfaces
- Reassembling everything correctly
- Tips to avoid leaks and common mistakes
If you’re keeping one of these Mazda trucks alive, this is a must-do service and surprisingly doable in the garage.

