fluid condition being dark or having particulate matter in it. late to engage into gear from neutral. slipping between gears. shuddering(actually torque converter issue).
total loss of all gears (not to be confused with a shifter issue-cable/bellcrank-app).
on some of the newer transmissions, some of those symptoms can be contributed to a shifter soleniod.
Smell. slippage, never had a cooler, discoloration of fluid. excessive leakage, harsh operation, delayed engagement. inattention to maintenance, continuing to operate it when it starts to actup. tampering, vandalism.
Slipping.
If it's an automatic, the first sign is a " mushy " shift. Instead of shifting cleanly it just sort of oozes from one gear to the next.
Transmission fluid smells burnt.
