e.alleg wrote:I ran it out of the housing and it's quiet. I turned the gearbox by hand and that's quiet too but I certainly didn't spin it very fast. It's possible I might have overfilled the gearbox, I took off the top allen plug and filled it up with 90w gear oil. I might try a new coupling if you know where I can buy one let me know.
Most bearing suppliers will have a big selection of couplings, Graingers would have them too but they can be pricey. If the hubs are good, just buy a replacement rubber. If the hubs appear worn at all, replace them too.
The gearbox should have a pipe plug or screw in the side for the high level. It should not be overfilled as it can damage the seals, generally they run about 1/3 full approximately. It should not be filled to the top.
The motor may run quite without a load and still have bad bearings, did you check the shaft for excessive end play?