what causes a starter to shatter?

[skata]

a jcb forklift with a perkins 1004 engine. went to crank it up, and heard an explosion! it did not sound good. fortunately i was able to get all the pieces out of the bellhousing. this is the second time this has happened. last time was about 10 years ago. why does this happen?

 

[hvy 1ton]

The kickout? is out of adjustment and the pinion gear was slamming into the nose cone.

 

[skata]

The kickout? is out of adjustment and the pinion gear was slamming into the nose cone.

shouldnt that have been good when i bought it new?

 

[Vetech63]

Make sure it is the right starter for that engine application .

 

[DMiller]

Start looking for something else broken allowing that to get side loaded, bell, flywheel bolting, ring gear shifted or someone failed to get fully on, something in there NOT right. Looks to be a Lucas?

 

[skata]

Start looking for something else broken allowing that to get side loaded, bell, flywheel bolting, ring gear shifted or someone failed to get fully on, something in there NOT right. Looks to be a Lucas?

This starter has probably been cycled a thousand times at least. Hard to imagine something not lined up.
I'm not sure who the oem maker is. But i think this starter is widely used among other brands.

 

[DMiller]

Does not change my first instinct. Starters do not just break apart randomly. If is a Lucas(Perkins was as was Allis a defined User) there should be a Delco replacement available, that will have a Cast Iron/steel nose instead of aluminum.

 

[hvy 1ton]

shouldnt that have been good when i bought it new?

It should have been, but it sure looks like the the pinion and nose cone have been making contact. Like Dmiller said, those nose cones don't shatter for no reason.

 

[TD24]

Last rebuilder put wrong pinion on it. Used to happen often on Delco's in Clark forklifts.

 

[RZucker]

Start looking for something else broken allowing that to get side loaded, bell, flywheel bolting, ring gear shifted or someone failed to get fully on, something in there NOT right. Looks to be a Lucas?

Looks Lucas or Prestolite to me... Lucas the prince of darkness. Used to deal with them on Ford tractors. Hated them. Even the Nippondensos on John Deere tractors were more reliable.

 

[hosspuller]

Picture allows high magnification. Looks like the pinion gear teeth are worn unevenly. (natural for a starter) I surmise the wear allows the pinion to climb on the teeth of the flywheel forcing the nosecone apart, Instead of engaging the flywheel teeth. Check if the pinion shaft is bent or loose. Would not take much movement to break the cast nose. Wear would explain the time between failures.

 

[rondig]

Mmmm i have seen this before...when my guys double start machine....or try starting when already running...

 

[funwithfuel]

I'm not seeing the pinion wear mentioned. I wonder if the hydraulics loaded up, that should have just slowed cranking rpm. But if the casting were porous, well any weak link, will lead to failure.

 

[hosspuller]

Click on Skata's second picture. Even looks like a tooth is broken off. (at the very bottom of the pinion pic)

I'm not seeing the pinion wear mentioned.

 

[Ronsii]

Click on Skata's second picture. Even looks like a tooth is broken off. (at the very bottom of the pinion pic)

Tooth is still there. it's just the angle of the pic makes it look like extra distance between the teeth along with the relief cut.

Most of the time I see the nose cones busted off was from machines that had the starter repeatedly engaged with the motor running.

 

[funwithfuel]

Just peeked again, I only see machined lead in cuts. But I'm old and eyes are shot.

 

[skata]

the gear teeth ends are machined like that. no wear. also, the ignition key doesnt allow you to re-engage the starter unless you turn the key to off.

 

[hvy 1ton]

Maybe I'm crazy, but that looks like contact to me.

This looks like a burr developing on the shoulder and there is shiny metal at the toe.

 

[TD24]

Agree with Skata... Brings up a thought.
Many machines are OEM wired so ign key will not fire the starter if engine is running and there is charging system output.
This function is dependent on the ign switch being OEM or equivalent and properly wired.
My question? Has the ign switch been replaced with an non compatible aftermarket?

 

[Ronsii]

My hyster forklift also has a mechanical interlock that will only one turn to crank without going all the way back to off to reset it.