There are u-joints involved with this but this could be a number of things.
Just to start with this being a manual transmission, this could be normal. I have driven hundreds of manual transmissions and know that when I get on the accelerator, off, and back on that it will clunk. This is called gear clash and it is normal. It is basically the gears in the transmission banging into each other.
To confirm this is inside the transmission, the way to do that is remove the rear driveshaft and drive the vehicle. If it still does it then it is in the front drive-train (transmission or differential) and not the drive shaft or rear.
This will at least limit it down to a couple of components. At that point we need to decide if this is normal or not due to it coming from in the unit. If it is, can you get a video of the noise and what you are doing to get it to happen? I should be able to help determine if this is gear clash or not.
Let me know what questions you have. Thanks
Images (Click to enlarge)
Sunday, June 28th, 2020 AT 8:02 AM