Starter question

DrankTheOrangeKoolaid

Member

Equipment
M6800/M920, Case 780B
Sep 24, 2019
99
34
18
Alberta
Earlier this summer the starter in my M6800 started acting up. Sometimes it would crank over and other times I would just hear the solenoid click. Then it gave up the ghost and would not crank at all. I pulled the starter and bench tested it. Solenoid was fine, but wouldn't spin. I gave it a small spin by hand and tried again, it spun. Tried a few more time, some times it would spin some times it wouldn't. I took it apart and started doing checks as per the WSM. When I removed the brushes, I noticed one of the brushes was stuck in the channel it slides in. I got the brush moving again and reassembled the starter. Put it back and the tractor fired right up... started better than it ever had since I owned it (normally it lugs when starting and takes 10 or 20 seconds to start, now it was starting instantly).

After about a month it started lugging again and today it will not crank at all. I am about to pull the starter and I expect to find a stuck brush again.

My question is, is there something I can use to lube that track or am I more likely to make things worse? I was thinking graphite powder.
 

lynnmor

Well-known member

Equipment
B2601-1
May 3, 2021
1,445
1,159
113
Red Lion
The graphite might help but know that it will conduct electricity and may cause some arcing. I would replace the brushes and maybe the brush holders.
 

dvcochran

Active member

Equipment
Kubota M9000, New Holland TN90, Deere 2640, Vermeer 504N, Vermeer 504SI, more
Feb 23, 2011
212
44
28
Dickson, TN
Earlier this summer the starter in my M6800 started acting up. Sometimes it would crank over and other times I would just hear the solenoid click. Then it gave up the ghost and would not crank at all. I pulled the starter and bench tested it. Solenoid was fine, but wouldn't spin. I gave it a small spin by hand and tried again, it spun. Tried a few more time, some times it would spin some times it wouldn't. I took it apart and started doing checks as per the WSM. When I removed the brushes, I noticed one of the brushes was stuck in the channel it slides in. I got the brush moving again and reassembled the starter. Put it back and the tractor fired right up... started better than it ever had since I owned it (normally it lugs when starting and takes 10 or 20 seconds to start, now it was starting instantly).

After about a month it started lugging again and today it will not crank at all. I am about to pull the starter and I expect to find a stuck brush again.

My question is, is there something I can use to lube that track or am I more likely to make things worse? I was thinking graphite powder.
Any good die-electric grease should work. Like this.
CRC Di-Electric Grease: Silicone, Clear, 10 oz, NLGI Grade 2, NSF Rating H1 Food Grade - 2F136|03082 - Grainger
You can find it cheaper.
 

DrankTheOrangeKoolaid

Member

Equipment
M6800/M920, Case 780B
Sep 24, 2019
99
34
18
Alberta
Dismantled the starter today. Always fun working on stuff in the snow at -5C. As I suspected, one of the brushes was stuck in its track. Removed the brushes from the tracks and used a small screwdriver to scrape the crud out of the tracks. Gave the brushes a light rub with emery cloth and put the brushes back in their tracks. They all moved much more easily. I opted to not use any lubricant. Reassembled the starter and reinstalled it. Tractor fired right up (after a few seconds of glow plugs).

If it happens again it is new brushes and brush holder, but that is a C$150 touch.
 
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BAP

Well-known member
Lifetime Member

Equipment
2012 Kubota 2920, 60MMM, FEL, BH65 48" Bush Hog, 60"Backblade, B2782B Snowblower
Dec 31, 2012
2,759
873
113
New Hampshire
I would check all your electrical connections from battery to starter. You may not be getting the proper amount of power which is causing the starter to develop this issue over and over.
 

DrankTheOrangeKoolaid

Member

Equipment
M6800/M920, Case 780B
Sep 24, 2019
99
34
18
Alberta
I would check all your electrical connections from battery to starter. You may not be getting the proper amount of power which is causing the starter to develop this issue over and over.
That was done earlier this year for a different problem. I have done a voltage drop test on both the positive and negative battery leads.