clunking noise

[AKA DUKE]

Just got my 77 FJ40 on the road. I noticed when starting out you hear and feel a slight clunk, then when diving about 40 mph in 4th gear when I let totally off the gas and coast, when I give it gas to get going again I hear it clunk again and can feel it throught the stck shift. Should I look more at u joints or could it be something in tranny?
Thanks in advance for any and all help.

 

[Zang469]

I would take a look at the u-joints first and go from there. Thats what it sounds like and hopefully is the easy fix, good luck, Z

 

[dargreg]

More like pinion slack, a loose pinion makes a clunk where as a universal will make a more tinny crunch as it transfers through the drive shaft.

 

[AKA DUKE]

I know this will sound stupid but this is also my first manual transmission, if its pinion slack is that normal? What has to be done to fix it if not normal?
Thanks again for any and all help.