Starter on the way out?

UP Oliver

Member
I have an Allis Chalmbers 840 end loader. It has been tough to start lately, turns over very slowly when I hit the button. I thought my batteries were down so I charged them both. I put them back in and hit the button and I got the same thing, turns over very slowly. It starts, but it takes a lot longer with the slow turnover. Is my starter bad?

I don't know what else it could be.

Thanks.
 
I just had the starter rebuilt on my '76 chebbie C20. It was getting real tired. Most days I had to tap on the case with a hammer to get the thing to fire up. It was turning slow...or not at all.
 
Thanks for the help. The guy that sold me the loader gave me a rebuilt starter as part of the sale. That was almost 11 years ago. I guess I will pull that off the shelf and put it in.

Thanks.
 
Just rebuilt one last month. New brushes and make sure the surfaces are not burned. Take it to some one who knows what they are doing if you have doubts. They need to be shimmed correctly to make the brushes do their thing. Mine turns over like a jack rabbit now.
 
You could check the battery cables for internal corrosion or other damage which would reduce the capability to deliver the juice. I'm sure you already cleaned and inspected the ground connections.
 
I thought the starter was going on my 2-135 White. I had it rebuilt and it was still turning slow. I had a loose ground cable. Not on the battery,but on the other end.
 
Check out everything as others have said but if you narrow it down to the starter go ahead and pull it off as the longer you use it the more damage you'll do to it, a worn bushing can run into internal damage to the electrical parts real quick And a quick fix becomes an expensive fix.
 
If you have a voltmeter it's an easy question. If not, Harbor Freight sells a slick little unit for $5.

Put the leads across the case (scratch off the paint for a good connection) of the starter and the power input stud, not wiring terminal, the 3/8" or whatever copper stud coming up out of the starter.

Hit the button, hold it and read the volts. If 10v or less for a 12v system, or 5v or less for a 6v system, your problem is not your starter necessarily (see later) it's a sulphated up battery that can't put out high current, or it's partially discharged. You can test for that by putting your voltmeter leads across the actual battery lead studs and measure while cranking. If you don't have 11/5.5v the battery is the cause.

If that's not the problem it's wiring. Either your cables are bad or the connections are dirty, not on the outside where you can see necessarily, inside where metal touches metal where the current flows.

Fine we got through that.....all clean and bright and tight.

Now we notice that the ground wire connects to the engine block via a steel screw on one side of the machine and the hot lead connects to the starter solenoid terminal. Fine.

First of all steel is not all that great of an electrical conductor. So you need a lot of surface area for good conductivity.

The path for the ground connection current to flow is from the steel bolt, through the cast iron engine block, over to the interface of the starter to the case of the starter and wala we have completed the path and the starter can spin.

But wait. What about the connection between the starter case and the engine block? Steel to steel, butt joint, hasn't been off or cleaned in 20 years sort of thing. The steel bolts have long ago developed a rusty scale.

Easy to see if this is the problem also. Just put your voltmeter on the WIRING TERMINAL that is under the steel bolt where ground is established to the block, and the other scratched into the starter case like you did initially. If you read anything in the way of voltage, you need to clean up that path.

On to the starting solenoid. This is your high current switch that you activate by the low current circuit associated with your starter push button, or key twist to start position. Inside are 2 hugh copper studs and a large copper disc that is sucked down to contact the studs (completing the circuit) when the button is pushed.

Over time due to the circuit parameters, the contact arcs and causes pitting, just like ignition points. Any pitting reduces the surface area of the contact. To pass high current you need lots of that. So if the solenoid is your problem, you will be able to read voltage across the two large terminals while spinning the starter. Time for another.

Once you have addressed all this easy stuff and it doesn't solve the problem, then you can do something with your starter. Sometimes it just means cleaning up the armature and a new set of brushes. Sometimes you need to include a new set of armature bushings with that. If it's worn beyond that time to bite the bullet and get a new one.

My 2c and I know it will help.

Mark
 
It could be a lot of things.... bad cables, bad ground, bad batteries, bad contacts in the starter switch or bad bushings or brushes in the starter motor... along with the possibility of a high torque load on the engine itself causing it to be hard to turn.
I usually prefer to hook an amp clamp over the battery cable and see what it's pulling... If it' drawing 1000 amps then right away you know the battery and cables are good and the problem is in the starter or the load it's turning. If it's NOT drawing hard... say 3-400 amps or less... then I'd look at the cables, batteries and connections first..

Rod
 
Thanks for this information, and everyone else also. I will perform these tests tomorrow and see what happens. When I charge batteries I use a charger that will de-sulphate a battery if it needs it and that function did not come up on either battery.

One question I have is the ground wire. Are you talking about the ground wire from the battery or some other wire?


Anyway, thanks again.
 
From the battery low side, - term for neg gnd systems and + terminal for positive gnd systems. No extra wiring, just one hot and one cold from the battery.

I had a JD with a 6v on both sides of the tractor. Wired in series with the one on the far side tied to the block as stated. Starter was real sluggish in the winter on my diesel.

I changed out both batteries to 12v and ran 2 wires from the far battery around the tractor and tied the ground side (- term) of both batteries to one of the bolts holding the starter to the engine block after cleaning up the spot real well.

The two hot posts I tied together (putting the batteries in parallel) and tied to the solenoid. That old diesel couldn't wait to light off when you hit the button.

Mark
 

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