I know there are a lot of threads on C3 starter problems. I've read as many as I can but I could still use some advice on what to do about my starter woes.
I have a 1973 SB 350. When I bought the car a year and a half ago, the starter sounded funny... mostly just very loud. The car was in the shop for a steering issue and I had them replace the starter. For a while it was fine, then it started making horrible grinding sounds when I tried to start the car.
The shop replaced the new starter for free (though I don't think they tested it) and put a mini starter on the car. It never sounded and acted perfectly, but it was an improvement, until recently. Now we're back to the same grinding noises.
I went under the car and checked out the ring gear. I didn't do a fully comprehensive examination, but it looks fine. The teeth on the bendix look OK too.
Then today, new problems: started the car in the morning with the same grinding noises, but it started. After the car got hot, the starter would barely turn over. I turned the key, and nothing for a second or two, then it turned slowly wouldn't start the car. Then the bendix kept spinning for about 10 seconds, even after I turned off the ignition. That's never happened before.
I know that heat is the enemy of starters. The starter is really close to the exhaust... but that's true for all C3s, right? I don't have a heat shield but I think I'll get one (might not help but can't hurt, I assume).
I'm sure this could be a bunch of things, but if people have advice on where to start, I'd appreciate hearing it.
Thank you!

 

If the bendix kept on spinning at the very least the starter solenoid is shot. The starter also may need to be shimmed. Did the shop check all clearances when they installed it?

 

I bought my 78 350 4 speed in 2005 with 59K miles and a rebuilt Delco type starter. Now I have 124K miles with that starter, it's been off to replace the oil pan gasket. I've driven the car from Syracuse to San Diego twice, across Death Valley and up Pikes Peak. It always started, went through three batteries in my corvette journey.
Not all C3's have starter problems.

 

My C3's have no issues.

I would check :

Clean all battery terminals. Clean the ground from the battery to the chassis, both ends.

check the ground from the chassis to the engine block

Check the cables for damage and corrosion.

Measure the battery voltage. Low battery voltage can fry a starter. As the voltage drops the amps go up.

Make sure the key is releasing the solenoid , that the key is not hanging up.

If the inspection cover for the flywheel is missing, replace it.

If you have headers , then a heat shield will help.

On a mini starter, make sure the solenoid and starter motor is clocked close to the block, not the exhaust.

Just some thing I would do... hope it helps..

 

C3 "starter issues" usually begin with headers. Instead of a single exhaust pipe next to the starter, there are now four pipes.

The grinding noise maybe an outcome of improper starter bolts. Those bolts must be knurled to prevent the starter from moving. Better starters will come with new knurled bolts.

Shims are seldom needed but to check flywheel to bendix clearance, the bendix must be forced outward with a screwdriver. That gap is 0.035 as I recall. Which by coincidence is about the same as a heavy duty paper clip.

A starter thermo blanket is a must with headers. Attach those with two SS band clamps.

Better starters come with H.D. solenoids and are more resistant to heat soak. Look for a brown cap on the end of the solenoid. That's ceramic instead of plastic.

There is a huge difference between a $39 starter and a $139 starter.

 

Hey guys, thanks for the suggestions. I don't have headers. Next weekend I'll get under the car, take some pics of how it's presently wired up, and remove the starter and check it out.
I'll post my pics and hopefully get some comments on whether it was done correctly or not. I'll look for the knurled bolts, I've heard before that those are mandatory.
Sounds like I at least need to replace the solenoid, and of course make sure all wiring is done correctly when the starter (possibly a new one) goes back on the car.
Then I'll hope for the best and let you know what happened.
Thanks again!

 

Check your wire end connectors for frayed or broken wires. Take the starter to a local starter rebuild shop and have them test it. The starters you get from the franchise auto parts stores are questionable on reliability.

 

Take it apart..they are simple..check bushings etc..solenoid ..post some pics

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