Manfrotto tripod problems: loose connector

[stkirkland]

Hi:

First post here.... I'm a digital video guy, but my question is about my tripod.

I use this tripod a lot for mounting a Cinevate slider onto. I believe, because I use it for this many times, I've loosened part of the tripod. I'd like to know how to correct this, if possible! Is there a way to tighten this or make it stick more tightly into the hollow shaft? Has this happened to anyone else before?

I'm attaching some pictures so you can see which part I'm talking about. Not sure of the name of this piece, but it's the part directly under the head, the silver metal base that has set screws into the lower metal piece. The lower piece has come out of the tube, which is in the middle of the legs. This piece inserts into the riser part, that can give your tripod head extra height if necessary.

Anyway, this is a Manfrotto MT294A3.