Ring Gear Broken Teeth

I got a unit in here with an 8.1 GM engine. Unknown history but the starter drive sounds like a little gravel running around in there. We suspected ring gear trouble but more than one noise per revolution.

The unit never sounded like it was missing any time being driven by the starter and we turned over the dead engine a fair bit trying to get a bead on what was happening. The problem may have gotten a little worse, read on.

Pulled the starter and right there looking at us was a freshly broken tooth off the ring gear. The starter spur gear looks perfect. The starter was freshly replaced by unknown parties for unknown reasons before we got it. It is an aftermarket unit with a Lester number on it. I suspect other teeth are broken too.

The wear pattern on the ring gear appears to indicate the spur gear only engaging about half way across the ring gear. The ring gear is installed as far forward on the flywheel as it can go.

I am thinking we will get the correct OE starter and ring gear so we are beginning with a known quantity here but wonder what others think about this. Halfway engagement depth seems like a bad idea but I don't see how it would cause a tooth to cleanly fracture off from one side to the other exactly.

My first guess is the wrong starter was installed.

Do you suppose spur gear too small, loading the tips of the teeth and breaking them off instead of the roots?

Pictures would help...

If not the starter then... flexplate on backwards....

or somebody changed something else and had to put one of these on the crank..


Speaking of flexplates.... I do remember they like to break!! and then shift around a little....

Check the crankshaft for end play as in bad thrust bearing.
Bob

Birken Vogt said:

Pulled the starter and right there looking at us was a freshly broken tooth off the ring gear. The starter spur gear looks perfect. The starter was freshly replaced by unknown parties for unknown reasons before we got it. It is an aftermarket unit with a Lester number on it. I suspect other teeth are broken too.
I am thinking we will get the correct OE starter and ring gear so we are beginning with a known quantity here but wonder what others think about this. Halfway engagement depth seems like a bad idea but I don't see how it would cause a tooth to cleanly fracture off from one side to the other exactly.

Click to expand...

That is a lot of force on a tooth / teeth with only1/2 the depth engaged.
I would suspect the wrong number of teeth on the starter drive.
Some starters have a pinion gap adjustment capability. Pinion gap should always be measured when replacing a starter. IMHO.

I give, what is that & what has gone so wrong as to need one?
Joe H

That's a wheel spacer.

It's a crankshaft spacer for if you are putting and older tranny on it... what is on the engine wasn't mentioned so who knows what someone else did...

Never saw or heard of such.
So it moves the flywheel back a bit?
Weird.
Joe H

joe--h said:

I give, what is that & what has gone so wrong as to need one?
Joe H

Click to expand...

Spacer plate. Very common on Chrysler slant six engines in Yale forklifts. You send one out for rebuild, remove and keep. It will get lost in the rebuilders vat.
Nothing wrong, just the way the Yale people set up the T/C-Tanny distance to use that engine in some models.