Starter not disengaging, shim it?

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Jordi

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So it has new oil, filter, coolant, cranked by hand fine.

Put some power to it and it span over on the starter, sluggish but span.

Turned the ignition off and it kept on spinning.

Checked around and the starter hadn’t disengaged from the ring gear. Thought the solenoid or starter might be jammed. Soon as i cracked the bolts to drop the starter out, disengaged.

Presuming the starter sprocket was wedged into the ring gear.

No weird noises, it engaged fine just wouldn’t disengage.

Does this sound like a shim issue? Had the starter out and there are no shims in it.

Its a 6.2 diesel incase that makes a difference.

Thanks.
 

Ricko1966

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Let's let ranch welder answer this one, he's so smart. Anyway starter that continues to crank is usually a low battery or dirty connection . The high amperage draws overheats and sticks the points in the starter solenoid together Try a fresh battery. If you still have a problem clean all the connections at both ends of the battery cables and engine,frame,body ground. If the problem still persists,attach a remote start switch at the starter and engage it that way,if the problem is gone it means you still have a supply problem,as in ignition switch sticking. edit.(ignition switch or starter relay sticking)If it's not gone replace the starter, the solenoid contacts are sticking.
 
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fast 99

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Let's let ranch welder answer this one, he's so smart. Anyway starter that continues to crank is usually a low battery or dirty connection . The high amperage draws overheats and sticks the points in the starter solenoid together Try a fresh battery. If you still have a problem clean all the connections at both ends of the batter cables and engin,frame,body ground. If the problem still persists,attach a remote start switch at the starter and engage it that way if the problem is gone it means you still have a supply problem,as in ignition switch sticking.Ifit's not gone replace the starter the solenoid contacts are sticking.
And here I thought the Boss Mustang folks were the only ones that didn't get along, silly me.
 

Jordi

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The batteries are almost dead in it. Been using the 4.7 V8 booster pack.

Have a look at all the connections tomorrow.
 

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Bigger batteries sourced. Big boost pack sourced.

Some circuit testing done.

Permanent live is good. Earth is good. Ignition live seems good, have power on/off as the key is operated.

Turn the key, starter engages. Release the key, ignition off starter stays engaged and continues to spin until the battery is disconnected.

Turn the motor a fraction on the crank with a ratchet and it disengages almost instantly.
 

Ricko1966

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Couple ways of checking this. 1, put a test light to the solenoid lead and ground.Crank the engine if the engine continues to crank after you turn off the key,look at your test light,if it's still lit your solenoid is getting power when it shouldnt. Id suspect the ignition switch.edit( I'd suspect the ignition switch or starter relay). If the lights out and its cranking I'd replace the starter. Another way would be engages the starter with a remote start switch,if you know how to short a solenoid to engage it that works too. If the starter continues to crank,replace the starter.
 
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Couple ways of checking this. 1, put a test light to the solenoid lead and ground.Crank the engine if the engine continues to crank after you turn off the key,look at your test light,if it's still lit your solenoid is getting power when it shouldnt. Id suspect the ignition switch. If the lights out and its cranking Id replace the starter. Another way would be engages the starter with a remote start switch,if you know how to short a solenoid to engage it that works too. If the starter continues to crank,replace the starter.
Is there not a start relay is this system that is known to stick as well?
 

Ricko1966

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Is there not a start relay is this system that is known to stick as well?
Buck has brought up a very good point. If that vehicle has a starter relay, look it up by year and model to check. I will edit my other 2 posts to include troubleshooting on a vehicle with a relay. If it turns out to be a voltage supply problem,post back up so we can walk you through testing the ignition switch and starter relay.
 
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Jordi

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It’s a bit of a frankentruck as it’s a C10 body on a K30 chassis.

Any idea or photos of where this relay is/should be?
 

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It is on a bracket in dash just left of the ashtray on mine, but it is CUCV (originally 6.2). They do not have the same harnesses. Just brought it up in the event it was an oversight.
 

Ricko1966

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Yea, I didn't know what he had, I thought only CUCV had starter relay,but IDK and my advice to look it up by year and model isn't great considering it's built from 2 trucks.
 

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Thanks for all the info chaps.

I’m away with work till fri/sat but will do more testing when I’m home and report back.
 

Jordi

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So this is taking longer than i want to figure out.

Pretty much ruled out it being a wiring issue. Disconnected all the ignition wiring. Battery straight to the starter and short the starter ignition to the battery, still sticks in.

Bench tested the starter multiple times. All seems absolutely fine.

I’ve fitted 5mm and it still sticks in.


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Any suggestions?
 

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Not sure why I’m seeing there. Is it a broken tooth on the starter sprocket? Do they line up well w the flex plate?
Are you sure it’s got the right starter in it?
 

Jordi

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Not sure why I’m seeing there. Is it a broken tooth on the starter sprocket? Do they line up well w the flex plate?
Are you sure it’s got the right starter in it?
All teeth look to be ok. I think thats just the photo.

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Thats the sticker off the starter. I’m presuming its the right one but couldn’t tell you. Its just the one that was fitted when i got it.

Number 323-447 tally with the gm starter listed on Rock Auto.
 

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