Update based on max value

I have two table linked together by two sets of fields. I am trying to get
Table A to update Table B based upon a max value of Table A. In my Update
To: row I am not sure how to build the field to indicate a max value. Any
thoughts?

UPDATE DISTINCTROW tblVMTW INNER JOIN tblFeederMilesYrly ON (tblVMTW.Year =
tblFeederMilesYrly.TrimYear) AND (tblVMTW.FeederNumber =
tblFeederMilesYrly.Feeder) SET tblFeederMilesYrly.actStart =
Max([tblVMTW]![actualStart]), tblFeederMilesYrly.actFinish =
Max([tblVMTW]![actualFinish])
WHERE (((tblFeederMilesYrly.Feeder)=7254));