TM issue

jasonfish320 · 06-04-10, 10:24 AM

Hey guys,

I have had my boat out on the water for few months now, but yesterday my TM started making a sort of grinding noise in the gear casing...It's an older '98 Minn Kota 82# Thrust. This unit had everything replaced 2 seasons ago..all wiring, armature, prop, etc. The grinding happens intermittently so its not consistent..i haven't run it since i started hearing the noise..maybe for a minute tops... I'm gonna tear into this weekend, but didn't know if you all might have suggestions on what it could be.. Also, this unit does not have bearings..so it's not a bearing issue. To make matters worse the repair shop that did the work 2 seasons ago won't warranty any of the parts and then proceeds to tell me they no longer service trolling motors...WTF!?

nofearengineer · 06-04-10, 11:06 AM

Jason, I don't understand how your motor can't have bearings. Are you telling my the rotor shaft is magnetically levitated? I was unaware MG or MK were doing that.

If it's not the bearings, it could be one of your commutator brushes is loose, and catching in the gaps.

jasonfish320 · 06-04-10, 11:12 AM

I know it doesn't sound right, but a good friend who is a certified tech. by merc/minn kota/yamaha/volvo/bombardier/etc. told me that it doesn't have bearings in the area where the noise is coming from, but some kind of bushing setup...I'm guessing you are right about the brushes being loose..I'm gonna find out for sure this weekend...I'm also thinking that the clip that keeps the pos.neg wires up away from the armature may have snapped and the grinding is from the clip getting caught up in the brushes...who knows..I'll figure it out tho.. I am relying on the 1% rule

nofearengineer · 06-04-10, 11:36 AM

Oh okay....no bearings "in that area" is different than "no bearings".

Plus, you've got the whole bearing/bushing...6 of one/half dozen of another thing.

The wiring clip is also a good suspect.

jasonfish320 · 06-10-10, 10:16 AM

OK so I was able to get my TM apart and remove the armature and check out all the "goods"..I found a fair amount of "brake dust" like powder that had coated some of the armature. The wires were all in-tact and no damage to any of the connections. The only issue that I could find that might be causing the brake dust buildup was that one of the brushes was sticking a lot more than the other and I noticed a few black marks on the armature where the brush had been grinding... so I cleaned up everything inside the unit and re-greased all the fittings. I have not yet tried the TM since I didn't have time last night to get it all back together but should be able to test it tonight and I will let you know of the outcome

06-04-10, 10:24 AM	#1
jasonfish320 BassFishin.Com Veteran Member Join Date: Apr 2007 Location: MAINEIAC Posts: 585	TM issue Hey guys, I have had my boat out on the water for few months now, but yesterday my TM started making a sort of grinding noise in the gear casing...It's an older '98 Minn Kota 82# Thrust. This unit had everything replaced 2 seasons ago..all wiring, armature, prop, etc. The grinding happens intermittently so its not consistent..i haven't run it since i started hearing the noise..maybe for a minute tops... I'm gonna tear into this weekend, but didn't know if you all might have suggestions on what it could be.. Also, this unit does not have bearings..so it's not a bearing issue. To make matters worse the repair shop that did the work 2 seasons ago won't warranty any of the parts and then proceeds to tell me they no longer service trolling motors...WTF!? __________________ "If at first you don't succeed; have another beer"

06-04-10, 11:06 AM	#2
nofearengineer BassFishin.Com Premier Elite Join Date: Mar 2009 Location: Southwest IN Posts: 5,630	Jason, I don't understand how your motor can't have bearings. Are you telling my the rotor shaft is magnetically levitated? I was unaware MG or MK were doing that. If it's not the bearings, it could be one of your commutator brushes is loose, and catching in the gaps. __________________ Many men go fishing all of their lives without knowing it is not fish they are after.

06-04-10, 11:12 AM	#3
jasonfish320 BassFishin.Com Veteran Member Join Date: Apr 2007 Location: MAINEIAC Posts: 585	I know it doesn't sound right, but a good friend who is a certified tech. by merc/minn kota/yamaha/volvo/bombardier/etc. told me that it doesn't have bearings in the area where the noise is coming from, but some kind of bushing setup...I'm guessing you are right about the brushes being loose..I'm gonna find out for sure this weekend...I'm also thinking that the clip that keeps the pos.neg wires up away from the armature may have snapped and the grinding is from the clip getting caught up in the brushes...who knows..I'll figure it out tho.. I am relying on the 1% rule __________________ "If at first you don't succeed; have another beer"

06-04-10, 11:36 AM	#4
nofearengineer BassFishin.Com Premier Elite Join Date: Mar 2009 Location: Southwest IN Posts: 5,630	Oh okay....no bearings "in that area" is different than "no bearings". Plus, you've got the whole bearing/bushing...6 of one/half dozen of another thing. The wiring clip is also a good suspect. __________________ Many men go fishing all of their lives without knowing it is not fish they are after.

06-10-10, 10:16 AM	#5
jasonfish320 BassFishin.Com Veteran Member Join Date: Apr 2007 Location: MAINEIAC Posts: 585	OK so I was able to get my TM apart and remove the armature and check out all the "goods"..I found a fair amount of "brake dust" like powder that had coated some of the armature. The wires were all in-tact and no damage to any of the connections. The only issue that I could find that might be causing the brake dust buildup was that one of the brushes was sticking a lot more than the other and I noticed a few black marks on the armature where the brush had been grinding... so I cleaned up everything inside the unit and re-greased all the fittings. I have not yet tried the TM since I didn't have time last night to get it all back together but should be able to test it tonight and I will let you know of the outcome __________________ "If at first you don't succeed; have another beer"

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)