noise on start up

[88911coupe]

'88 3.2 167k, new starter about a year ago.
On occasion I get an odd noise at the instant the car fires up. It's a instantaneous, metallic "whack" sort of sound...sort of hard to describe. It's sort of like something is catching for a millisecond on the starter. When I changed the starter I rotated the engine and could see some "slightly" worn teeth on the starter ring (correct term?)...could this be the cause? It never occurs other than for the briefest instant during start up and the car runs reasonably well otherwise.
Let me know if there are other more serious problems that could be causing this.
TIA

[Zef]

After 20 years and some 167 K...seem reasonnable that the ring gear has some worn spots...Is the new starter a new one...!...Look like the starter clutch take just a little too much time to release...IMHO...!

[Superman]

I have noticed a similar noise, and have discussed it with others. My current belief is that this is the sound of the starter nose gear being ejected from the ring gear and hitting its resting place abruptly. I think the engine and the ring gear is THWACKING the nose gear back into the starter.

I think my noise started when I disassembled, cleaned and lubed the starter mechanisms including the nose gear stuff.

[88911coupe]

Now that you mention it, it may technically have been rebuilt. I'm thinking it's probably the worn spots on the ring gear though. What causes the starter gear to return to it's "resting" position? Is it when the engine fires up and starts spinning faster than the starter?

[Superman]

Yes. The starter nose gear has front faces that are square and rear faces that are beveled. When the starter turns the ring gear, it is spinning relatively slowly. When the cylinders fire and spin the ring gear, it accelerates that ring gear very quickly. This physically throws the starter gear back toward the starter. I think the noise I hear is the starter gear mechanism hitting its rest stop.

The noise I hear is like a fairly heavy "snap."

[Shaun @ Tru6]

It could just be worn teeth, but it could also be a sticky pinion gear on the starter. I had the same noise and it got worse, then a little more worse but still just a "chuck" on start-up and then it was gone, and then of course the gear really stuck once.

You may want to pull the starter out and test it, and also get underneath with a flashlight haveing a friend turn the motor in gear to check for worn teeth.

the carnage on a 69E with flywheel and ring gear as one unit