What size bolt head is this?

[CurrentObsession]

Trying to get this zinc off and cant get to the bolt holding it on.

I can't believe I am even having to ask this as I've done this before a few years ago on a similar drive. I have tried both deepwell 7/16 and 1/2".....9/16 wont fit down the hole. What am I missing?

 

[Grub54891]

Sometimes you have to use 1/4" drive sockets on them. 3/8" is to big.

 

[alldodge]

Need a thin wall socket. Would say what size is needed maybe if I knew what your working on

 

[Scott Danforth]

most likely a 3/8 hex. however could be 7/16". I dont really remember. I usually pull the drive to make life easier. that way you can also take care of the waterpump.

 

[Bt Doctur]

GEN II is 1/2 inch using a 1/4 inch drive set

 

[CurrentObsession]

Got them out with 1/4 drive.

​Many thanks for the suggestion.