There is a rattle coming from the distributor shaft.What would cause this? on 1990 Ford Ranger

Could it be the intermediate shaft retainer?

Asked by for the 1990 Ford Ranger
yes it could be
Should I remove the oil pump in order to replace the shaft? Would this problem be affecting my oil pressure and fuel mileage? My engine makes a clicking noise and my gas mileage is less than 15 mpg.