Have a 3 year old MM1. Today while plowing, the motor just quit. I thought the solenoid was burned up so I shorted a screw driver across the terminals. Got a big spark, but the motor didn't run. I suspect the motor is shot. Any opinions?
When I picked up the new motor today I asked the dealer if it was common to have to replace motors after 3 years. He said no, but asked if we greased the thrust washer every year. I know where the thrust washer is, ( its the fiberglass washer on the motor shaft that rests on the pump housing) but I never heard of any maintenance that was required. Makes sense to me, but why isn't it mentioned in the owners guide?
This is the 3rd vehicle with the Fisher MM system that we have replaced the motor on.
Things get hot in a hurry when the thrust washer gets dry and yes it should be in the manual,i think they figure because it's fiberglass that it won't heat up so much.I pull the cover every fall and smear a little grease in there.
Joey,pull the 2 bolts off the top of the motor and pull the motor cap off,if it's never been off you'll have to "help" it a little ,be carefull though because it is pinned to line the bolts back up properly,anyways,pull that and the washers will be staring at you,apply some grease to the top of the shaft also,not alot,just lube her up abit.
Let me clarify,CPSS and i mention that it isn't in any manual to grease the thrust washer,though it should be,A friend of mine tested my motor once when i thought it was bad(he rebuilds electric motors) and he said it isn't a bad idea to get a little grease in there every now and then,more so on the older motors but nonetheless a good practice that can't hurt anything,not to heavy on the grease though,you don't want it all over in there!
The washer is on the bottom of the armature shaft, between the pump and the motor. There is also a washer on the top of the shaft, underneath the cover with the "tit" on the top. After you remove the cover as ArcBurn said, grab the shaft and lift the entire motor and shaft up. Dont let go of the shaft or it will fall out of the bottom of the motor. (Its a little tricky to get the 4 brushes pushed back to slip the armature shaft back in if it comes out). After removing the entire motor, the lower fiberglass thrust washer will probably be stuck to the hole on the pump. Gently pick it up. apply grease to the pump bronze bearing, both sides of the washer, the bottom armature shaft,then slide the washer on the bottom of the shaft, and slip the motor back on the pump. Be careful not to drop the armature out the bottom of the motor case. Turn the shaft with your fingers till it lines up with the pump shaft and drops in a little. Apply grease to the top washer and bronze bearing in the cap and reassemble. I also applied a thin film of grease to the bottom and top of the motor case to aid in future disasembly.