The only way to service the transmission properly is to do one of two things.
1) Do a full and proper transmission fluid flush, using ONLY Mitsubishi Diamond SPIII Transmission fluid. A full transmission flush is done with a vacuum flush machine. It removes all the old aged ans useless fluid, and re-installs clean fluid, and friction modifiers that preserve the transmission clutch packs and flywheel.
2) Do a full transmission overhaul. Replace and obviously worn, or required parts. Replace and parts that are recommended, flywheel, clutch packs, etc. since the transmission is apart. Rebuild, and re-install ONLY Mitsubishi Diamond SPIII fluid.
Most likely the darker fluid color means the clutch packs are somewhat worn, and could truly probably use a overhaul. But, a full and complete fluid flush should do the trick nicely at only 121,000 miles. And don't let any mechanic tell you it is a bad thing to flush the transmission fluid. A Flush is complete, removing all old fluid contaminants, and filling with completely new fluid.
Bookmarks