Binding Motor

[GolfMechanic]

Cart: 2000 Carryall 2
S/N: E0013-879624

TL;DR Motor won't turn with wheels after reintallation of the motor.

I'll try not to make this too long. Had a cart that had been down since I started working as a golf cart mechanic. Originally it had a charging problem that was fixed by replacing the on-board computer (this is unrelated to curent problem). After having been driven for the first time in 6 months, I found out that there was a rumbling sound coming from the rear end. I thought, sounds expensive I'll worry about it later. Also the gear case (passenger side, motor side) had been broken so that you could see the inside of the motor but the motor was still bolted on.

Later on, I decide to take it all apart. I tear down the motor, gear case, and axles to find possibly a bad bearing or missing teeth on the gears. All looks good except the plastic bushing insulators had broken in the motor, as well as the pre-mentioned broken gear case. I figured that must be the problem. I put back the gear case and axles and installed them back into the cart. I go to install the motor but I notice that after bolting the motor in, when turning the wheels as if to simulate driving, the motor won't spin. Pushing the cart while on the ground feels like the brakes are bound but they're not, it's the motor.

I end up spending the money to replace the broken gear case thinking that it must of lost it's shape and it was misaligning the motor. I install new case but still the motor is bound up. Not sure what's wrong.

Thanks

[NoleFan4Ever]

What did the motor do when out? Did it spin freely, did you replace anything - brushes, bearings etc.?

[GolfMechanic]

The only parts I replaced were those bushing insulators that insulate the brushes from the stator wiring and the gear case. Everything else is original. The motor will spin when you place the motor vertically on a table. You can wobble it ever so sligtly inside the motor casing but I'm not sure if that's considered normal.

[NoleFan4Ever]

And with the motor out the GB turns freely? So only when you mate them up it is then bound?? (just trying to get a feel what you are seeing)

[GolfMechanic]

The gear box turns freely when the motor is not connected. In fact, that's kind of how I knew originally that something was probably wrong with the motor. I rode down a hill without the motor installed to see if the rumbling went away (which it did). Not the best test method but it was the only thing I could think of that would rule out axle bearings and differential.

When I first installed the motor, it was to the broken gear case (although it still had holes to mate the motor), so I was able to see if the motor was spinning or not. The broken case gave me a view into the motor from the top. If I loosened the motor and kind of tilted it up, it would stop binding. This was what made me think the case was more than just cosmetically damaged but that it was possibly misaligning the motor.

Alas, with the new gear case, it's still binding.

[NoleFan4Ever]

Wow.... It would almost have to be in the alignment as something would have to be a quite a few .000's off one way or the other. But there should not be any play in that motor when you tilt it so something is amiss there and I am assuming when you bolt it up tight, it is binding the shaft and ~may have been the original reason the other GB housing broke.

I would tear that motor down now. There is a centering kit https://www.revolutiongolfcars.com/p...ng-kit-am10039 but that is for noise and not binding, so the motor needs to be pulled down and I believe you will find the root cause there.....

[GolfMechanic]

So I took the motor apart and I decided to attach the back plate of the motor to the armature while it's outside of the motor housing. I tightened the bearing retainer plate so that the back plate is attached to the armature so they're one piece. I noticed there's a little bit of play between the bearing and the back plate even with the bearing retainer tightened well. By play I mean I can wiggle the plate back and forth while the armature is standing up vertically with the plate on top.

Is this normal? I would think that the plate shouldn't wiggle at all while the bearing retainer is tightened.

[NoleFan4Ever]

No it should not. Something is worn, amiss or damaged I suspect.

[Sergio]

It has to be the bearing since the armature is attached to the inner ring and the retainer and the endcap hold the outer ring.

[GolfMechanic]

Yeah, I looked at the bearing further and it definitely has some play, although the bearing spins nicely. Hopefully that's what fixes it. Thanks you guys!