Differential chatter- cart barely moves

[Sixpack57]

2004 TXT 36v, lifted 22 in tires

When the accelerator is pressed slightly, I can get a little movement. More pressure, and the rear starts to chatter. I figured stripped hub. I replaced both of them, along with some other stuff while it was torn down. Remounted everything, and have the same issue. Pulled the end cap off of the motor, and the motor isn’t turning. I read about low voltage can cause this symptom, low and behold, have one battery @ 4.2 after resting from charge.

I know the bad battery is an issue, but is there something else in the diff that might cause this? I did hubs, brakes, motor bearing, spring/brush plate. After all of this, nothing changed.

Any thoughts are greatly appreciated!

[Raystar57]

That battery is probably your only issue except 36 volt and 22 inch tires.
Convert it to 48V and be happy.
Then you can do controller and motor as required.

[Sixpack57]

I agree with you on the upgrades, but I’m just fixing this one for a friend. Have another stock TXT that I’m going to pull one battery, swap it, and see what happens.

Thanks for the response!