Reply to "Pinion Question"

quote:

Originally posted by PanteraDoug:
I tend to agree with ItalFord.

What does the wear pattern look like in that area on the ring gear?

I personally would want to see a loading pattern (wear pattern) on the teeth.

It might just be that portion of the gear flaked in that spot OR for some reason developed rust right there?

********* Doug, the gear tooth is beginning to fail at the points you see fracturing and material shedding. There does not need to be direct tooth contact here. As this area continues to shed material the tooth WILL begin to flex more and more until, worst case scenario, it has a catastrophic failure and I do mean catastrophic !!
As I stated in my first post on this, it "may" take some time to reach that point depending on the easy or hard of a life it leads. I he were to decide to leave it in, the teeth should be looked at least once a year to see how fast they are deteriorating. You would be amazed how fast this could go bad....a risk I would never take personally or allow one of my customers to take. It is like playing "Russian Roulette" with your transaxle...*************

That COULD be an indication that there is no direct tooth to tooth contact in that spot.

There is no guaranty that a new ring and pinion would not show some kind of a "concern" in spots on the teeth.

******** The "NEW" ring and pinion will NOT show this indication or concern as it is new! You must remember that this pinion could have been in use for the last 46 years and is finally showing its' age. **********

I would guess that you would want to do some kind of a surface imaging on both.

Many years ago Chevy was having problems with the 427 steel crankshafts. The hardening process that they went through were showing spider web pattern cracking on the bearing surfaces AFTER they sat on the "shelf" for a period of time.

Chevy removed them under fear that they would fail in competition. I don't remember what the fix was. It MIGHT have been caused by "tough-triding" the cranks?

It's a long time ago and I just don't remember specifically, just generically.


The other thing is that all designs have stress factors in the calculation (a safety factor). It could well be that the gear is already oversized and probably has a 85% (or less) stress loading. Parts are rarely stressed 100%.

Supercharging something like a 427 probably would be the concern here.