I picked up all the stuff from Deere few weeks ago to change my 4720s oil,fuel filter and hydro filter and the deere Hydro oil 2 five gallon pails. Was wondering about cleaning the magnets I saw mentioned for the 400 hour service? Where are they whats all that about? Not gonna change oils till the spring. Tractor is in shop for winter so I let the old oil sit and collect the moisture then change it for spring.