Starter Issues with the C10

[socalfandabodys]

I recently picked up a 1969 C10. The owner told me it needed a starter. I installed a new starter and it started up fine the first time. As soon as I shut it off and went to start it again I heard the most horrible clanking/grinding noise. I went back to the auto parts store and tried a different starter. Same thing happened. I tried shimming the starter in all configurations and it made no difference. I also replaced the alternator,battery and battery cables. The truck will eventually start if you crank it over a few times but, it makes a horrible noise and shakes the whole starter bad. Any ideas on what it could be.

[ssealeycpa]

If you have an automatic transmission, I bet your flywheel (flexplate) is cracked close to mounting bolts. You should be able to kill the ignition and have someone spin the motor while you look at the flywheel to see if it turns in an erratic fashion. If this is the case, you can take out the bellhousing bolts and put in two 3/8" threaded rods ~5" long (in the middle bolt holes) and slide the transmission back far enough to get to the the crank bolts that hold the flywheel (If I'm not mistaken, it is has an 11/16" head on the bolt so if you have a long wrench you can access the bolts). If this is the case, this will relieve you of removing the transmission. Hope this helps.

[406 Q-ship]

Check the bolt to make sure they are real starter bolts and not just hardware store bolts, starter bolts are knerled by the head of the bolt. I would also check to see if the mounting pad on the engine block isn't FUBARed, I had seen them all busted up which wreaks havoc on starter alignment. I have seen the aluminum starter noses from the major rebuilders be of a poor fitment quality (offshore universial casing) causing grinding, this was the issue with my 350/350 C10. I replaced the starter nose with one from a Manual trans that is made of case iron.

[David Pozzi]

Auto trans or 4 speed?
Look at ALL the flywheel ring gear teeth. Common issue is the engine usually stops on a "favorite" cylinder or two, this means the starter often engages the same few teeth when you hit the switch. If those teeth go bad then every time the engine stops at that spot, you will have a bad starter engagement. The starters with bolts in line near the flywheel require a support brace from the front end of starter to the engine block, the staggered bolt type used on auto transmissions do not need it.

[406 Q-ship]

Auto trans or 4 speed?
Look at ALL the flywheel ring gear teeth. Common issue is the engine usually stops on a "favorite" cylinder or two, this means the starter often engages the same few teeth when you hit the switch. If those teeth go bad then every time the engine stops at that spot, you will have a bad starter engagement. The starters with bolts in line near the flywheel require a support brace from the front end of starter to the engine block, the staggered bolt type used on auto transmissions do not need it.

Good point David, I forgot about the bracket on the starter motor. I have seen the staggared bolt patterns with that bracket too.

[David Pozzi]

Your advice on the bolts is very true, the early 80's starters that were smaller diameter used smaller shank bolts and they would allow the old style starter to twist out of line.
David

[socalfandabodys]

This problem existed with the old style starter with bracket installed on the front. Right now I am running a smaller high torque starter out of an Astro Van and am still having the same problem. I'm also running starter specific bolts. I'm guessing it is the flywheel.

[modular93fox]

wonder if you have the wrong flexplate and starter combo... ? good luck counting the teeth with the flywheel installed, but its worth a shot.
clint

[socalfandabodys]

Well guys I figured I had tried everything excoet replacing the flexplate. I took ssealeycpa's advice sliding the transmission back and replaced the flexplate. Well it seems to have fixed the problem. I have driven the truck a dozen or so times and it is starting great. The old flywheel seems to have been slightly bent. Thanks guys.