grinding in my transmission i think

[countryboy]

about a month ago i started to hear a grinding noise in my transmission but it does not happen when i am shifting but it happens mostly in first gear when i am at a high rpm can someone please help me

 

[rhino]

Pull it down to manual low and drive it. If the grinding is there, shift it to second and see if it stops. If it does, it's the low/reverse planet. Rebuild time. It's a pretty common failure.