Change gear with uranium implement (5)
I believe the answer is:
auger
'implement' is the definition.
(auger is a kind of implement)
'change gear with uranium' is the wordplay.
'change' indicates anagramming the letters.
'with' means one lot of letters goes inside another.
'uranium' becomes 'U' (U is the chemical symbol for uranium).
'gear' with letters rearranged gives 'ager'.
'ager' going around 'u' is 'AUGER'.
(Other definitions for auger that I've seen before include "Boring-tool" , "something that's boring" , "Tool for boring holes in wood" , "Boring instrument" , "A drilling tool" .)