Been hearing a grinding noise from the gear box of my 7 year old Minnkota trolling motor. Is this common? Can it be lubricated?
Thanks
MM
Been hearing a grinding noise from the gear box of my 7 year old Minnkota trolling motor. Is this common? Can it be lubricated?
Thanks
MM
Grinding noise when you turn the motor left/right, or when the prop turns?
If it's the latter, then you have a problem. My guess is that you had some water enter the lower unit, it rusted out some of the components inside, and those rusted bits are causing the grinding noise. Either that, or the bearing is shot.
If you want to take it apart, you can get schematics (and any parts you'll need) from Northland Marine. Looks like the PowerDrive drawings are at:
http://www.northlandmarine.com/Minnk...PARTS_DIAGRAMS
Some of the links don't work, they made a mistake in the web addresses and you have to get rid of the extra "PowerDriveV2%202008-09/" in the URL.
Let me know if you decide to go this route, I can give you some tips and suggestions.
Shinbob, waiting the link you provided to download. Anyway, it's not the lower unit, works fine. the top unit makes a louder than normal noise when the motor is activated. Also, my foot control pedal doesn't turn the unit right anymore since I last used it.
MM
Sorry, can't help you too much with the upper unit. Are you saying that when the prop is turning, there is a grinding noise from the head unit? That's odd, as there should be nothing mechanical going on up there if the only thing turning is the prop motor.
The shaft on my terrova is hollow, and is essentially an open tube leading from the lower unit to the top, i.e. not capped at all, so it's possible that you may be hearing noise from the lower unit being transmitted to the top? I'd still pull the prop and see if there's anything odd going on with the shaft.
I've heard of some issues with the powerdrive foot pedals -- checkout the iboats forum, they may be able to help you more over there. If you have a multimeter you can at least isolate the problem to either the foot pedal itself, or the trolling motor.
Call John at http://www.jonestrollingmotor.com/ and he can probable make a diagnosis over the phone and tell you what is wrong and if you can fix it yourself. John is a great guy and his service is world class.
I listened to Devor last time I needed trolling motor parts and called John at jonestrollingmotor. John is very knowledgeable and has a huge inventory of parts in stock.
When I ordered parts last he was away from his desk but told me it should be around $60-65 (which is what it priced out to be from a different online retailer ) but if the parts were cheaper I would see it on my statement.
Sure enough when I got the parts it was $45. He could have easily charged me the $60 like I said was fine on the phone but he didn't. He now has a loyal customer for as long as he is in business.
Update--Boat was in the driveway & I turned the trolling motor on. What I heard was the lower unit noise transmitted to the top while in the water...damn! Sounds like gravel or foreign object. Will take prop off to investigate.
Thanks, Shinbob!
Took off prop n lower unit housing...rusty water came out..rust around the seal..sounds like a bad bearing...
Read my post #5. John can help you out with your problem.
The brush and seal kits come with everything you need to rebuild, including a new bearing. I've found that most of the rust came from the two screws that hold the bearing plate in place, so I replaced the ones that come with the kit with stainless steel screws.
Be sure to put everything back together the way it was originally, if you reverse the power leads, or reverse the brush plate orientation relative to the main body magnets, then the motor will run backwards.
The only tricky part for me was getting the armature back between the brushes. Until I figured out that the little cardboard tube that came with the kit, that I thought was just packaging leftovers and I almost threw away, was actually there to keep the brushes open so that you can slip the commutator between the brushes. Was also a bit of a challenge to get the old bearing off the armature, but I let some rust penetrant sit on it for a few days and just hammered it off. And one of the long through-bolts seized a bit with corrosion, so that it actually twisted when I took it off and was longer than it was supposed to be. I just ordered two new through-bolts (they were like $2 each), put anti-sieze on the threads, and it was fine.
Oh, and if there's corrosion on the commutator, sand lightly with 800 grit sandpaper to make sure there's a good electrical connection. They're copper, so if they're not actually copper colored, then they need to be cleaned.
Other than that, it was a piece of cake to repair. Took it apart after a few days fishing to see if the seals held, and there was not a drop inside.
Last edited by shinbob; 04-03-2015 at 08:04 PM.