TERRIBLE sound when starting

[dmartin1]

lately when i go to start my stepside, (355 sbc) it will turn over and randomly a big CRUNCH sound will happen usually twice them the starter acts normally and starts the engine.

anyone else experience this?

doesnt always do it, but most of the time.especilly when the truck has sat for a day or something.

[jrblanke]

Have you had the starter off at all?

The reason I ask is because I had a similar problem about 6 years ago. I ended up replacing a solenoid, but I also discovered that my vehicle needed shims that go between the starter and the block. I do not remember what corrected the problem (whether it was the solenoid or the shims. I had that same grinding noise though.

[CountryGirlT]

First thing I'd do is shim the starter. I just experimented with adding and taking away clearence to see how it affects the noise. It helped my truck quite a lot, now the cranking sounds smooth.

[BLE 'BURBAN]

The best way I have found to shim a starter takes a bit of time but I have found that taking this extra time eliminates alot of headaches later on and longer starter life as well.

1. Disconnect the battery.
2. Remove flexplate dust shield from bottom of tranny.
3. Remove the starter from engine.
4. Remove starter solenoid from starter.
5. Remount starter WITHOUT the solenoid to then engine.
6. Reach up and pull back on the plunger to move the starter drive gear into the teeth of the flexplate.
7. Using a wire feeler gauge measure the gap between the tip (crest) of the tooth on the drive gear and the bottom(valley) of the teeth on the flex plate. It should be no more than .060" NOTE; A large paper clip works well for this measurement if you don't have a wire style feeler gauge
8. If it's right, put it all back together then you're good to go. However if it's too tight or too loose, then you will need to shim it.
9. If it's too tight start with a shim that's .015" thick and shim both mounting points between the starter and block then measure again. If it's too loose then shim out ONLY the outer mounting bolt to cause the starter to tilt into the block.
10. Play around with the shimming until you achieve the proper gap of .060"
whether it's by no-shim ,full shim or half shim on either bolt.
11. Once you've got it set put'er all back together and drive on.
Yes it is time consuming and tedious but you will be pleased with the end result.

[fireman428]

I have learned over the years if my starter goes out to retain the nose cone from the original starter if thats possible from the factory . you never have to shim the original starter cone from the factory .there machined to fit the block and line up with the flywheel / flexplate .

[dmartin1]

This actually is the factory starter.
I got a new motor in the truck and the started didn't do this for a few months then randomly started doing it.? Ill try the shimming.
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[csb#356]

Check and see if the bolts are tight and that they are correct starter bolts. You can't use any old 3/8" bolts. Ble burbans method is definately the way to go. It is a lot easier than randomly putting shims in and seeing what happens. Mine actually had to be shimmed closer in to the flywheel (also a factory starter). Do a good inspection of your flywheel also because if it has done that for too long, you are likely missing teeth or have worn the teeth down.