machinegt

I have noise coming from my automatic transmission when it reaches 2500rpm
and the transmission is running at 5th gear (because I know it's not in 4th gear otherwise
it would running alot faster rpm at the speeds i'm at)

The noise is like a rotating/uneven vibrating sound.

After 20mins of driving the noise goes away.

Should I be worried, and what could the problem be?

lex400sc

Are you sure it's originating from the tranny? It could be the sound of a heat shield resonating at that rpm. I had that same problem and it turned out the heat shield on the cat was bent too close causing a buzzing/wheezing sound. If that happens to be the case, crowbar the shield out more or just remove it.

machinegt

o ya that might be the case for me too, i just heard it coming from the center console, so i assumed it was from the transmission. i'll check it out thanks.

THE_CEO

Do a search this is a very common vibration for the SC's

CEO

SupraCoup3

if it sounds like you're driving over rumble strips or a washboard, it could be your torque converter. The SC400 needs its ATF changed every 15,000 miles according to the manual, and it needs to be replaced with T-IV ATF.

I had this problem with my 400 a few years ago, and a powerflush @ the dealership fixed it.


John