[52super]

I have a '52 Super with a dynaflow showing 61,000 miles it was a daily driver until it suddenly developed a loud whine that i can't seem to pinpoint, it comes on at around 40 mph. This is hard to explain but sometimes when you accelerate it goes away, and it gets louder when you let off it, I was close to home when this happened, and did not drive it again. The transmission oil level is full and it seems to work fine not ever giving me any problems, any thoughts??

[old-tank]

Your service manual will have some troubleshooting tips. Noises from the rear end can sound like coming from the transmission.