Flywheel or Starter?

[Thisissam34]

Hi everyone,

I have a 1985 k5 blazer with the 6.2L diesel in it. I've had more starting problems with it than i could've imagined. The starter grinds no matter what I do. The starter in it is brand new. I've used the three standard shim sizes that you can buy from the parts store. The brace at the front on the starter is on and tight. I've recently noticed that it grinds at the same point continuously. The motor will turn for a second then grind, turn for a second then grind, so on and so forth. This made me believe it was the flywheel that was causing the grinding. I've looked at it briefly in the past and the teeth seem fine but ive never turned the motor and looked to check all areas. Looking for any opinions on the problem. Thank you!

[Robyn]

Sounds like a bad section in the ring gear.

Drop the flywheel cover and have a peek.

Bar the engine over and look at the entire gear.

A ripped up section will foul your day.

If its not real bad (deep) you can sometimes dress the teeth with a die grinder to get a bit more use.

If they are real bad, then its yank the tranny and replace the flex plate.

6.2/6.5 only, nothing else fits.

K5 will have a 700 R4 so you need a flex plate for that app (bolt circle is smaller than the one used on the TH400)

Good luck

Missy

[Thisissam34]

Thanks for the help. Ill take a better look at it and see what i can find.

[More Power]

When looking for a replacement flexplate, the parts counter guy will likely ask if this is for a light-duty or heavy-duty application.

As Robyn mentioned, the torque converter bolt-circle is the difference. The TH700R4 is the light-duty transmission and the TH400/4L80-E is the heavy-duty transmission.

The two available flexplates are exactly the same except for the TC bolt-circle. Jim