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Weak starters

RobVG

Senior Member
Joined
Jun 20, 2009
Messages
1,028
Location
Seattle WA
Occupation
17 excavators and a stewpot of other stuff
Someone mentioned 'weak starters' in the "addicted to either" thread. I've run across that problem once on our Hino, thinking at first it was the batteries but it wasn't.

What is going on inside a starter that would make it weak? Didn't appear to be shaft bushings.
 

willie59

Administrator
Joined
Dec 21, 2008
Messages
13,930
Location
Knoxville TN
Occupation
Service Manager
Most common problem with the starter motor is with the brushes, brush holders, and the commutator on the armature. If the brushes don't make good connection to the commutator, it causes the motor to drag and draw excessive amperage, which in turn creates heat in the components. Goes down hill fast after that. ;)
 

2stickbill

Senior Member
Joined
Nov 1, 2009
Messages
677
Location
Romayor Texas
Occupation
Sniffin diesel fumes.
I had a F250 with the ol 7.3.New starter then was about $600 at dealer.About $450 at auto parts.Electic repair shop here $100 Remove repair and install.Told me when it first starts to drag let me fix it.He said most people keep on till it burns up.I had them to repair it at least three times in four years and 500,000 miles
 

Randy88

Senior Member
Joined
Feb 2, 2009
Messages
2,154
Location
iowa
We've had several over the years that had problems and no rebuilding would solve the problem so we exchanged them for a rebuilt starter to eliminate the problem and pass it onto someone else. With all the machines and vehicles we have we are always rebuilding either starters or alternators on something and with starters Atco's right on the money with his explanation. Brands make a difference as well, I've worked years to eliminate all the delco staters on everthing I own, alternators are fine and easy to rebuild but the starters are junk and never get done working on those. All brands have their perticular set of problems and there's no perfect solution but some are worse than others for some reason. Another major culprit is the ground, if you've got a weak or bad ground it seems to wreak havock with starters if not taken care of right away.
 

MTI Mark

Well-Known Member
Joined
May 11, 2011
Messages
53
Location
Northern New York
One thing to keep in mind when checking a "dragging" starter, is to check all the battery cables and clean every connection. I have seen experienced techs replace starters, then have to actually fix the cable problem when the new starter didnt work any better than the old one. Those crappy bolt on battery terminals are the worst invention in the world. They are ok to get you out of a bind, but not for long term use. If you have starter problems and have bolt on replacement battery terminals, start there in your diagnosis.
 

RobVG

Senior Member
Joined
Jun 20, 2009
Messages
1,028
Location
Seattle WA
Occupation
17 excavators and a stewpot of other stuff
Our Thomas skidsteer always cranked slowly. It got worse and the guy's were able to jump start it when needed. I wanted to put a starter in it but the boss said it couldn't be that because it jump started. Well it quit last week and couldn't be jumped. Put a new starter in and it fires off like a champ. I'm guessing that the extra 2 volts when jumping was enough to push it to start. Don't really know.
 
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