94 Caravan Transmission clunk

I have a 94 Grand Caravan, and the transmission clunk at low speed or stop and go traffic. Or, if I accelerate little bit and then decelerate during 1st gear. It only happens when the car is slowly moving on 1st gear such as traffic jam. Sometimes, it clunk on reverse gear, but the clunk will be less if it stops on neutral first before the reverse. Otherwise, the transmission is still very strong. It is a Jasper Transmission. I think I have this issue from Day 1 after the installation few years ago. Any advices!

Could be a worn inboard constant velocity joint on one or both half axles or the differential gears have too much play.