Change the transmission filter and fluid. Confirm the cooler lines are connected correctly, that the lines and cooler were flushed and a new torque converter was installed at replacement, and that the fluid has not run low. Gray-brown fluid indicates overheating and possible internal clutch-pack failure. If warranty coverage remains, have the installer inspect it.
The owner of a 1994 Jeep GC automatic 4x4 said the transmission fluid looks gray-brown instead of red and that the vehicle shudders and stalls in reverse only after warming up. Feathering the throttle allows reverse, but only at higher speed. The replacement transmission has about 10,000 miles. The expert said the fluid color indicates overheating and/or failing internal clutch packs, recommended a filter and fluid change, and advised checking cooler-line routing, whether the lines and cooler were flushed, whether a new torque converter was installed, and whether the fluid has stayed full. Warranty inspection was also suggested if coverage remains.
