* Low transmission fluid: The most likely culprit. Check the transmission fluid level *while the engine is running*. Low fluid can cause overheating and slipping. If low, topping it off might temporarily fix the problem, but a leak needs to be found and repaired.
* Low transmission fluid quality: Old, dirty, or burnt transmission fluid loses its ability to lubricate and transfer power effectively. A fluid change and filter replacement are likely necessary.
* Internal transmission problems: This is a more serious issue. Worn clutches, a failing torque converter, or other internal components could be causing the slipping. This usually requires a professional transmission repair or replacement.
* Transmission cooler issues: If the transmission cooler is clogged or malfunctioning, the transmission fluid may overheat, leading to slipping.
Before doing anything else, check the transmission fluid level. If it's low or dirty, that's the first thing to address. However, even after adding fluid, if the problem persists, you should take your Navajo to a qualified mechanic for a proper diagnosis and repair to avoid causing more damage to the transmission.
