Mystery Pic

[One-more-time]

Before opening the case on my 911 I saw this nicked/broken gear tooth The picture was taken from the right chain opening . Cracked the case and found no other damage, or the broken off tooth. No damage to the inside of the case in the gear area either. Anyone see this before ??


Thanks

Matt

[Walt Fricke]

Well, the tooth could have come out during an oil change. Especially if your car is pre-3.2 and has the plate, and maybe someone took the plate off for good measure when draining the oil. Though the right chain housing oil has a more circuitous route back to the sump than the left.

Small stuff like that tooth chip can live comfortabley down in the sump for a long time - valve adjusting nuts can, for instance. Of course, are you feeling lucky?

Doesn't explain why it broke. A missed shift just when that particular tooth was starting to engage the crank gear?

Walt Fricke

[Flat6pac]

When you open the case, youll probably find it parked behind the oil pump
Bruce

[JFairman]

It probably came out with the oil during a change.
Looks like a corelating mark on the steel crank gear about 8 teeth over to the right from when something was maybe crushed and broken there.

It may have been a cam woodruf key or cam gear timing pin was dropped and bounced on in there while someone was replacing and or timing the cams sometime in the past..
A rocker shaft lock nut could do it too but gravity will usually keep things like that down by the oil drain plug and oil pick up screen.
It's a good idea to stuff paper towels into oil return tubes when working on the valvetrain and under and above the timing chains where things could fall and bounce/slide into the engine case while working in those areas.

If the motor was turned over or running and a small steel part got on the aluminum intermediate shaft gear teeth and got crunched between it and the steel crank gear, then what you see there could happen.