Greetings!

I have a TH400 that was built last year. The builder has since died...

So far its been a great trans. Nothing major done, reverse manual valve body, steel front drum, 4 clutch direct pack, stuff like that. was supposed to handle up to 1200 hp

So this trans is sitting in an all steel vehical, with no padding and I can hear everything this things doing. from the first time this thing went in it made this noise in 1st and 2nd gear whenI would let off the throttle and coast. Describe it as a whirring noise...I was told t was an over-run clutch and that it was normal. Last night, it started doing the same thing in 3rd gear, and it never has before....problem?