8 3/4" Mopar Rear..Humming Noise over 40 mph??

[PT64POLARA]

Hey guys. My 64 Dodge has its original 8 3/4" rear with Sure Grip and 3:23 gears. The car has 63K original miles on it. Since I have gotten the car all I have done is add a little bit of gear oil. It feels strong, but I am getting a humming noise over 40 mph when the car is under load (only when I am giving the car gas.) Anything I could do, or is it just age catching up? Worth changing the gear oil? Any specific gear oil? Thanks in advance..

[big gear head]

This could be a bearing problem. If the car has sat for long periods of time then rust could have built up on the bearings. A complete rebuild might cure the problem. If it's the gears then you might want to just live with it.

[Ishmael]

I had the same problem with an 8 3/4. I can't remember the bearing name but it was right at the snout of the rear (man that didn't sound right). Big Gear Head is probably right but a bearing and some fluid is an inexpensive gamble that might solve the problem.