[Tigers] Expansion Tank

[larryall at pacbell.net]

Recently I checked the fluid level in the expansion tank.  When I put the cap
back on, the cap did not come to a stop.  It turned until the 'ears' of the
cap came off of the ramp flange.
Is there supposed to be a stop at the end of the ramp flange?  I don't know if
mine wore off or broke off but I am sure that I used to be able to turn the
cap on tight and have it hit a stop.
 
Please advise.