96 CC Humming Sound Help!

[ScottG24]

I have searched this site for months hoping to find help about the noise my cart is making. I finally made a video to see if someone can share more insight.
here is the history...
Bought used, replaced all the bearings in the rear end housing (one was busted).
Took the motor to the local motor shop to be checked out, they re-sealed? and done $200 worth of work on it. said it was fine. took apart the brakes and used a wire brush to knock off all the dirt/rust. cleaned it up inside pads/hubs really well. replaced brake lines. cleaned resistor coils one at a time, they were covered in rust/mudd. the one on the passenger side/end got caught in the wire grinder and bent a little, but i straightened it back. I cleaned up the nuts and bolts holding the coils on, but I think I replaced a few washers? not sure if they are the same metal as the original ones? Could these be whats making the noise?
the noise occurs when pressing the go pedal, and stops when I let off of it. I know it's not bearings or brakes because this is the only time the noise occurs. Don't hear the noise in reverse. added a 2 minute video. Please Help!
Thanks
Scott

96 Club Car golf cart noise - YouTube

96 Club Car golf cart noise - YouTube

[scooterman]

Hey Scott, for 220$ the guys at Plum Quick could of rebuilt that motor. There isn't many moving parts, you have the motor, rear diff. brakes. I would be suspicious of the 200 charge to look at your motor and seal it which doesn't make sense to me. I'll bump your post up so some of the other cart guys will have possibly seen or heard this noise before. I'm not a cart expert just adding my thoughts and limited experience thoughts on this.

[mrgolf]

Not sure if the gear mesh is adjustable, but it sounds to me like loose gears.

[Golfdog]

Have a similar noise in my 2000 car and after stripping the transmission concluded that it was the gears in the differential. They do have thrust plates (shims) but not sure whether you can get different thicknesses to take up slack.

[ScottG24]

Thanks. Everything went back together according to diagrams/parts index that I found online. If it was in the rear end, it would make the noise while rolling with my foot Off the GO Pedal? right? I'm thinking it is electrical.

[branson]

You know how a standard transmission with a lot of miles on it will be difficult to get into first and second. Sometimes they even make more noise in the low gears. I think it is because those are the gears that have the most time in them.
The teeth could be worn more on the forward side. Have you tried different viscosity oil in the rear end to see if the noise changes any?
Another idea is with a resistor cart in reverse it only uses half of the batteries. That means the motor gets half as much voltage as in forward. In the video it looked like you went faster in forward than reverse. You could try to temporarily run forward on half voltage to se if that quiets it down. You could also try reverse at full pack voltage to see if it is louder.

[Golfdog]

Originally Posted by ScottG24

Thanks. Everything went back together according to diagrams/parts index that I found online. If it was in the rear end, it would make the noise while rolling with my foot Off the GO Pedal? right? I'm thinking it is electrical.

The noise does not sound electrical and the absence of noise when foot off the pedal is quite normal. I would still suspect wear, the reverse does not make a noise because the car hardly uses reverse in relation to forward. I was once reminded that these transmissions are not precision built with low tolerances but more like an AK47.

[scooterman]

It really doesn't sound that loud, mine makes a little noise also but nothing to worry about unless it got really bad. I'd build the cart then address the noise later If it gets worse, until then crank up the radio LOL.