Replacement starter motor 11 teeth pinion gear vs 10 mismatch

97 Dodge Caravan SE, 2 wheel drive, 3.3 engine

I purchased a rebuilt starter motor at AutoZone, the rebuilder is Duralast in TN.

The rebuilt motor appears to be the correct dimensions to match my old one. However, my old one has 10 teeth compared to 11 on the rebuilt unit.

Duralast provided a toll free 800 number. I talked with someone there, who claims the OEM units can have 10 or 11 teeth on them, and that I can use the 11 teeth one, and that it will work fine. I am very skeptical, and I told him so. He suggested taking it back to AutoZone and have them look for a unit with 10 teeth.

My local AutoZone store only stocks one or two units at a time. They have no others in stock right now. They will be getting one or two more in next Wednesday. The store manager did not know which it will be. He says the restock quantity is done via inventory control from the main office.

Is there anyone here with any knowledge/experience with this?

Thanks.

wrote: 97 Dodge Caravan SE, 2wd 3.3 L

I purchased a rebuilt starter at AutoZone. It seems to match the dimensions of my old one, except the rebuilt has an 11-tooth pinion, where the old one had a 10-tooth pinion.

I talked with someone at the rebuilder, Duralast in TN who claimed the OEM units can have 10 or 11 teeth on them, and that the

11-tooth one will work fine. I was skeptical, so he suggested taking it back to have it replaced with a 10-tooth unit.

My local AutoZone will be getting one or two in next week but they don't know whether they will be 10-tooth or 11-tooth units.

Is there anyone here with any knowledge/experience with this? _______________________________________________________

1.) A pinion gear and its ring gear must have the same tooth pitch. The tooth pitch is the pitch distance tooth-to tooth, measured along the actual line of contact between the gears. On each gear this line is called the pitch diameter.

2.) If you replace a 10-tooth pinion with an 11-tooth pinion of the same pitch diameter, the 10 per cent mismatch will damage the gears.

3.) If you replace a 10-tooth pinion with an 11-tooth pinion that has a 10 per cent larger pitch diameter, the gears may match properly, but this will bring up another problem: the larger diameter pinion must be spaced or shimmed further away from the ring gear to avoid clashing.

Good luck.

Rodan.