Noise in back end

[tdump]

My 36 volt 1991 Marathon that i let my dad use has developed a noise in the rear end.
I thought it was the left axle bearing. Well, after having to cut the brake hub off,mashing the heck out of the end of the axle,cutting into it and on and on, I finally got the bearing out,not bad. So all that 200 bucks worth of parts for nothing.I took the cover off the read end,upside down,how nice, the carrier bearings were a bit noisey,so I replaced those. All put back together and still have a noise,a bit different but when you are giving it go juice,you hear the noise,you let off the go pedal and the noise all but goes away.
I am wondering if I went to the wrong end,could it be a bearing in the electric motor? Everything I have touched on this cart has required extra work to remove. even to adjust the brake cable hook up to the pedal, I had to heat the adjuster.
Anyhow,I just need some input on other sources of noise? or should I plan to pull the motor and put bearings and maby brushes in it?