Starter Ring Gear Failures

[CTN65]

We are on our second ring gear on our 04 Duramax. The first one wore thru in two locations (I assume the engine stops in these two points when shut down). We are now getting ring gear wear on the new one - less than 6 months old. The starter grinds for 2-4 times before engaging like before. Starter has also been replaced when the ring gears were changed. The gear on both starters look good, I think there may be a heat treat issue on the ring gear itself.

Any thoughts?

Thanks,
CTN

[More Power]

This is the first I remember hearing about starter ring gear wear issues. How do you use your truck? Lots of stops & starts? Cold weather operation? Does the engine start quickly when the starter works correctly?

Jim

[ToddMeister]

Has the machining dimensions of the block on the starter mounting surface been inspected? Seems like the starter mounting holes may be out of position, or the flat mounting surface not machined correctly.

[Duramaster]

Who is doing the repair work? Are the flywheel bolts being replaced when the flywheel is pulled off? Those bolts (8 of them) are torque to yield, not reusable.

[More Power]

We are on our second ring gear on our 04 Duramax. The first one wore thru in two locations (I assume the engine stops in these two points when shut down). We are now getting ring gear wear on the new one - less than 6 months old. The starter grinds for 2-4 times before engaging like before. Starter has also been replaced when the ring gears were changed. The gear on both starters look good, I think there may be a heat treat issue on the ring gear itself.

Any thoughts?

Thanks,
CTN


One post with a question then no followup?????

[CTN65]

Thanks for the responses. I've been away fro a few days. The truck does see an amount of cranking - my wife's vehicle doing what they do. The torque-set bolts were replaced with the ring gear at repair and the truck starts ok when engaged.
The first time thorugh we thought that it prboably was the heat treat on the gear, the second leads me to agree that there is a dimensional issue between the crank flange thru the engine to the mounting pad for the starter, not letting the spur gear to fully engage with the teeth on the ring gear. The spur gear is showing no wear which bothers me, since I think that is supposed to be the softer of the two. If it is dimensional, I doubt that I have much recourse.

Would there be much use in taking material off the mounting face of the starter to increase engagement?

Thanks again,
NTC

[DmaxMaverick]

Take some measurements, and verify the gear lash. If there appears to be too much clearance, then some material has to go. I would take it from the starter. Not only is it much easier, you can always go back. If you remove material from the block, you can't undo it. If some clearance needs to be tightened up, I'd suggest having the starter mount surface milled, and have some shims made at the same time (up to the material thickness removed, in small increments). If you have to replace the starter in the future, you can either have the new starter milled to the same spec, or reuse the starter housing with the remaining new starter parts.

[More Power]

Maybe the starter solenoid simply isn't moving the starter drive far enough.

Jim

[CTN65]

I thought the same, but the starters we replaced also.

I had a thought over the weekend of a weak battery not giving enough current to keep it engaged.

NTC

[DmaxMaverick]

I thought the same, but the starters we replaced also.

I had a thought over the weekend of a weak battery not giving enough current to keep it engaged.

NTC

If it doesn't have enough juice to stay engaged, it won't turn, either. The starter field is energized by the engagement of the solenoid and drive gear, and not before. This is the nature of the GM "piggyback" solenoid/Bendix design. This is why, if the battery output is low, it just clicks or buzzes.

[madmatt]

I did several of these back in 04 and remember there was a part # change. Could the new part maybe not have been the updated version???? I thought there was a bulletin issued for it but i just searched for it and came up empty handed.