from tkinter import *
from time import sleep
root=Tk()
c = Canvas(width=460,height=460,bg='grey80')
c.pack()
x=10
y=10
predmet1=c.create_rectangle(x,y,x+100,y+40,tag='tank',fill="gray")
oval=c.create_oval(x+45,y+10,x+75,y+30,tag='tank')
predmet2=c.create_rectangle(x+75,y+17,x+110,y+23,tag='tank',fill="gray")
def funk(event):
    predmet4=c.create_rectangle(x+110,y+17,x+117,y+23,fill="gray80",outline="gray80")
    while True:
          c.itemconfig(predmet4,fill="black")    
          c.move(predmet4,5,0)
          c.update()
          sleep(0.02)
c.focus_set()
c.bind('<Button-1>',funk)
root.mainloop()

 def funk(event):
#     predmet4=c.create_rectangle(x+110,y+17,x+117,y+23,fill="gray80",outline="gray80")
    predmet4=c.create_rectangle(x+110,y+17,x+117,y+23, tag='shell', fill="gray80",outline="gray80")  # добавить tag
    while True:
        c.itemconfig(predmet4, fill="black")
#         c.move(predmet4, 5, 0)
        c.move("shell", 5, 0)       # использовать tag
        c.update()
        sleep(0.02)