clunk when pulling away

I havent found info yet so posting. I have a 1985 defender and when pulling away feel a thump at the rear as if slack is being taken up i have ordered new u/js and will hopefully get them done on return home next week any ideas what else it could be never had this on any vehicle ive had before any info or link appreciated
thanks

I'd sort the u/j's and see if that sorts it first

Hey - I had the same clunk but was also shaking like a leaf whilst driving - it was indeed my UJ's (infact replaced the whole propshaft) and cured it - best of luck....

I too get a Clunk sound from the front, especially when changing gears on the highway! There is a play in my prop shafts and maybe the diffs.

Thanks all looking through the internet it was also mentioned it could be the a frame joint so ordered a new heavy duty adjustable one only £12.00 so what the heck. I'll give feedback on the result.