Transmission issue

I have a 2000 Silverado 2500 HD, 6 liter engine. The transmission warning gauge has been showing it's overheating. I changed the filter and fluid and the gauge still shows red warning. Any ideas on next steps?

1st thing is to take it to a reputable repair shop and have it scanned for tranny trouble codes. Might cost 35-40 bucks, but it's really the only way to see what needs to be done next. If you do this we will need the DTC numbers, not the description.

Welcome to AF.

I have a 2000 Silverado 2500 HD, 6 liter engine. The transmission warning gauge has been showing it's overheating. I changed the filter and fluid and the gauge still shows red warning. Any ideas on next steps?

high temps means its slipping. this can be from low pressures. low pressures may mean a crack in the shell or worn valve bodies. since this is a 2000 when has the fluid been changed to dexron VI or synthetic mercon transmission fluid from the old non GM spec dexron III ? if this vehicle has had dexron III since 2000 and the fluid was changed at every 50K plus miles, then the metals in the transmission are most likely damaged from the dexron III acidic fluid. this type fluid turns to acid after 20-30K miles,,,. with a diagnostic pressure test this can be determined why its too hot.. too hot is 190 deg F with no load no towing no speeds over 80MPH. most operate at 175 DEG F... what can also cause this is low/high fluid levels. air bubbles in the fluid. restricted damaged cooler lines ...