We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we’re looking for causes for recurring starter failure.

P.M. Carson City, NV

Q: My 1968 El Camino has a 350 engine hooked to a TH-400 transmission, and it’s going through starters like crazy. When I turn it over, I hear a scratching sound. I tried shimming the starter, but it didn’t help. What should I do?

A: Let’s dig in and see what’s going on. First, remove the starter and flexplate dust cover. Rotate the flexplate and check it for cracks or other defects (a turning tool—like Lisle’s flywheel turning tool—makes this a one-man job). Next, thoroughly clean all mounting surfaces, reinstall the starter, and manually engage the pinion gear. With the gear engaged, measure the backlash between .020 and .035 inches—you may have to add shims to get it just right. Also, you should have at least 1/16-inch of clearance between the engine side of the flexplate and the front edge of the pinion gear (check this in three locations as well). Finally, clean all the electrical connections and make sure the engine is properly grounded.

If you’re installing a new starter, you’ll also want to check out our quick guide to troubleshooting aftermarket starter problems.

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Author: Dave Matthews

Dave Matthews was a mechanic for the U.S. Army, a Ford dealership, and served for many years as a fleet mechanic for construction companies. Now a technical content producer at Summit Racing, Dave has spent decades working on everything from military vehicles to high performance race machines.