SOLVED - Flexplate or Starter?

[Shibbershabber]

1999 Yukon 5.7, AT

Grinding and screetchy while starting... not every time, but enough to be concerning

Is there a way to tell if one or the other is the problem (or am I missing something else?)



I know Ill have to get in there eventually... but its freezing and muddy out there... gathering intel first

 

[wjburken]

1999 Yukon 5.7, AT

Grinding and screetchy while starting... not every time, but enough to be concerning

Is there a way to tell if one or the other is the problem (or am I missing something else?)



I know Ill have to get in there eventually... but its freezing and muddy out there... gathering intel first

Take your starter off and see if you have A) missing or worn teeth on your flex plate, B) missing or worn teeth on your starter C) wear marks that indicate your starter is not fully engaging.

 

[Shibbershabber]

Just curious...

looking at parts and I notice two different starter options... Direct Drive and Permanent Magnet Gear Reduction...

Both show as fitting my Yukon, whats the deal?

Are they both going to fit but are different internally or is going to be one or the other?

 

[Shibbershabber]

Just for fun...

Heres a video. Sounds a little better here actually...

goes on a bit since the truck wont start right now...... another mystery.... anyhow, you can hear the sounds pretty clear

When it stops raining Ill get that starter out and have a look at things.

 

[exp500]

If you find nothing abnormal like loose starter, Check starter for failed bendix, test with jumper cables too. If it still grinds may have to measure for shim- drill bit or wire between the gears. If it still grinds look for cracked flexplate.

 

[Shibbershabber]

Just out of curiosity, what damages or cracks a flexplate?

 

[exp500]

Right foot or bad luck.

 

[Shibbershabber]

It was the starter.

Installed new one and its smooth as eggs.

Crazy difference.

 

[exp500]

Jumb- Please Edit your post title- add "SOLVED". Makes navigating and searching easier. Thanks.

 

[Doubeleive]

Right foot or bad luck.

explain how the gas pedal is going to cause the flex plate to crack

 

[Tonyrodz]

Right foot or bad luck.

explain how the gas pedal is going to cause the flex plate to crack

Both of my Express van flexplates cracked. 01 and 05.

 

[Doubeleive]

Both of my Express van flexplates cracked. 01 and 05.View attachment 263924 View attachment 263925

but what caused that? faulty casting? if anyone was going to break a flex plate from a heavy foot that would be me and I never had that problem ever, broke pretty much everything else though

 

[Tonyrodz]

but what caused that? faulty casting? if anyone was going to break a flex plate from a heavy foot that would be me and I never had that problem ever, broke pretty much everything else though

I was told because I floor it all the time. I pull alot of weight--maybe that's why ??

 

[OR VietVet]

But, you are sitting still when you crank the engine and then after the engine starts the flexplate just spins and spins and spins and spins.......that cracks me up.

I have seen the flexplate crack because of age-best I could guess, poor quality part, accidently turning the key when the engine is already running and mis-torgued flex plate attaching bolts and in an extreme instance, too much end play/wobble at the crank or torque converter and even a loose starter mount. I have also scratched my head and just said, "I got no ******* idea why it cracked".

 

[Doubeleive]

But, you are sitting still when you crank the engine and then after the engine starts the flexplate just spins and spins and spins and spins.......that cracks me up.

I have seen the flexplate crack because of age-best I could guess, poor quality part, accidently turning the key when the engine is already running and mis-torgued flex plate attaching bolts and in an extreme instance, too much end play/wobble at the crank or torque converter and even a loose starter mount. I have also scratched my head and just said, "I got no ******* idea why it cracked".

that makes more sense

 

[OR VietVet]

I forgot one that I saw once. An engine was partially in a hydraulic set up from head gasket leakage into a cylinder and while cranking it would hesitate on the compression stroke and after a couple times of that the flexplate cracked.

 

[exp500]

Right foot easier to say than Thrust bearing wear in engine and crank walking- Tony's pics show that well.
It is only a piece of 1/8 inch steel, I'm surprised it doesn't happen more.