Weird clunking in transmission while downshifting..

[GothicKidd]

What would cause the transmission to clunk while downshifting.. from.. 3rd to 2nd (i think) .. Cruisen down the street doing 40-50..and slowing down a little bit.. it will clunk.. You cant really feel it.. but you can hear it.. sometimes it doesnt seem like it doesnt go into gear for a bit.. and will be like clunk clunk clunk.. and go into gear..
also.. doing 60+ and taking your foot off for a second and putting it back on.. It will Clunk.. and you can feel it and defiantly hear it..
I do think my U-joints could be the problem..? Yes/ No?

[VR_Acclaim]

Cvs, centre bearing or dog does it has IRS if so it mayb a cv

[woteva]

Broken engine or gearbox mounts ??

[immortality]

also check the fluid level

[GothicKidd]

When I had it serviced, they told me that my main seal was weak or w/e and needed replacing soon... so Im losing transmission fluid.. VR_Acclaim do you recon if I got a transmission service that they'd fix them? :\