6.5 Starter Help

[Tfj5757]

New poster, not sure if this is the right forum.

Starter bolt popped out, replaced it, but ever since then it just sparks when trying to turn on. Starter has maybe 4000 miles on it.

Took this video, if anyone has a suggestion I'm pretty desperate for this to work work.

https://youtu.be/vKclEOr88YM

[JohnC]

Puzzling...

It appears to be sparking between the pinion and the ring gear, which onthe surface would indicate a bad starter ground. Why the ring gear is better grounded than the starter doesn't make sense, though...

I think I'd remove the starter and bench test it to see if I could find anything unusual.

[snarl]

That's not electrical sparking. The starter is twisting out far enough to grind the flywheel. Do you have the rear bracket installed?

[Yukon6.2]

My diagnoses
X2 on the starter not being bolted down completely.Front brace missing...?
Starter nose deformed from front brace missing and bolt falling out.
Thanks for the video,makes the diagnoses easier.
Remove the starter and check the nosecone for cracks and deformed holes.
Get new GM starter bolts and front brace.
Install and re torque the starter bolts at each oil change.

[trbankii]

Yep, you can see the starter move away from the flywheel, bind, and throw sparks. No bueno… You’re going to bust the starter mounting tabs off if you keep that up.

[JohnC]

I need new glasses....

Is there something on the ring gear that's forcing the starter out? (how can you make utube go one frame at a time?)

[DmaxMaverick]

I agree with the others. Definitely inspect it and secure with new bolts and the bracket.


I need new glasses....

Is there something on the ring gear that's forcing the starter out? (how can you make utube go one frame at a time?)

There's an app for that. "Video Downloadhelper" is an add-on for FF and Chrome. It lets you capture the stream off Youtube and save it locally. Then, open it in a video viewer. For better frame breakdown, import it into a video editor, which will normally allow advancing by 0.001S intervals.

I did that, and it definitely shows a "favored" section of the ring gear, where it fails. The video resolution isn't good enough to make out individual teeth while it's turning, but there is a pronounced "shiny" section about 2" long (0:03:010). As the starter is turning, it's normal until the "shiny" section reaches the pinion. Sparks fly and it stops with the trailing end of the "shiny" section under the pinion (0:03:018). The "shiny" section could be cause, or effect. Either way, it's likely damaged, and should be easily spotted if you turn the engine by hand/wrench.

The attached images show the "shiny" section of the ring gear just before engaging the pinion, and the position when it is stopped under the pinion when the fireworks start.

[JohnC]

I slowed it down to 1/4 speed ( a youtube function), full screen and 720P, and you can clearly see that the "shiny" part never makes it through the starter. The flywheel stops there and oscillates back and forth 2 or three times before coming to a stop. Either there's something on the ring gear or there's something locking the engine...

The whole engine shakes when it stops. I'm wondering if the engine is hydrolocked, or something similar.

[Robyn]

V8 engine generally stop in only a few places, and these will be evident by areas where the lead in to the gear teeth are more worn than other places.

This being said, the likely hood is that the ring gear teeth have worn to the point that they have failed in the "Favored spot"

Bar the engine over and examine the teeth carefully all the way around and get a good look at what's there.

May be time for a fresh flex plate.