8.9 HP motor on 1999 DCS rearend noise

[Ez2GoSC]

Hi everyone! I bought a used cart a few years ago. Just recently started to notice a clicking sound in the rearend when letting off the accelerator. This noise occurs when the cart is coasting but will stop when ignition switch is turned to off position. While moving at low speeds for extended period of time the cart will stop after a few minutes with resume normal operation after cooling down. I've read this is an issue with DCS. Long story short while replacing, testing, and investigating I found a 2004 8.9 hp motor on my 1999 cart. Here is what I know about the cart and done so far. 2.5year old Trojan Batteries maintained, checked /cleaned all connections and grounds, checked solenoid, replaced microswitch, replaced 400 amp controller(refurbished), checked brakes (no dragging or binding) Still an aweful clicking (sounds like the rearend is about to come out). Being that the noise stops when the ignition switch is turned off, I leaned towards electrical/wiring issue... I'm at a loss. Especially since finding this 8.9 hp motor. What other upgrades are needed to match the motor. The cart is used around our farm little to no grade (mostly flat ground) occasional trips when we camp. Any ideas or words of encouragement greatly appreciated.

[JohnnieB]

I'm speculating, but it sounds like the gears are worn some and the regen braking ceases when the key is turned off, so the noise goes away.

What make/model controller?

What make/model motor?

What is the overall tire height?

----------
Sepex motors don't like running at low RPM and the field map in the controller probably doesn't match the motor.

The controller going into over temperature shut down is a pretty good indicator the controller, motor and final drive ratio (tire height plus differential gear ratio) aren't well matched with how cart is being used.