Starter Grind Roulette

[Starwood]

Cranking up the 70 Stepside I got about 9 months ago has been a Vegas play since I drove her home. Early on - on very rare occasions - there always starter engagement - but then followed a very disturbing grind. However, it seems to be happening more often. Lately, I've been wincing when I turn that key.

Is this a simple shim issue - or something bigger involving the flywheel that may require a visit to the Transmission Pros?

Thanks in advance for any replies.

[72c20customcamper]

My 85 was doing the same thing all good for a long time then the grind started every so often and it got worse as time went on . I changed it out with a powermaster mini starter no shims and its smooth as snot again

[Rickysnickers]

Could be shims. It's also worth checking the teeth on the flywheel/flex plate too. That is something you can check yourself. Very easy to do. Take the starter off, and if you have somebody to help, use a socket and ratchet to turn the bolt on the crank snout. If not, you can just just it yourself too.

[sick472]

Shim problems in my experience have been....

Too many shims, and the motor will turn, but often let off a fast paced whizzzz after the motor starts as it kicks the starter gear back with super speed and force.

Too few shims and it does one of two things...

1.) The starter gear hits the flywheel and does not engage and makes a horrible grinding noise without even turning the motor over.

2.) Or, The starter gear engages, turns the motor over, it starts, but the starter gear stays engaged with the flywheel and makes a horrible noise as the starter continues to spin at engine RPM's. I suspect this could be your problem. The starter gear is too tight to the flywheel and gets stuck. This sound is just like if you turn the key, get the motor started and keep the key turned so the started stays engaged. It's not the grinding of teeth, but more that the starter is being spun much faster than it wants to be spun.

[Bullzak_83]

I agree with Rickysnickers,
just replaced mine a couple of days ago on my 70 cst10. The flywheel is missing some teeth, not enough that I am going to worry about it, but like you say every third or fourth start I get that funky sound, and Idid have to add a thin shim my was grinding when I first installed.

[Big Kev-O]

All good advise and I would add to remove the flywheel dust cover to check the gear mesh & check around the flywheel bolts for a cracked flywheel. You should be able to put a large paper clip or 1/8" allen between the gear mesh. The only way to check the gap is to use a screw driver to engage the starter's bendix gear. You should probably disconnect the battery for saftey purposes when manually engaging the gear.

Here are some good pics.

[Starwood]

Thx Fellas. Just might have saved me a trip to the Transmission Shop!

[dmjlambert]

I saw a video on youtube where a guy painted a few teeth of the starter's teeth with white paint prior to installing the starter. Then after starting the truck a few times he took the starter off and looked at the paint to see the amount of shimming needed. He was looking for the paint to be scraped off about 2/3 the way down into the starter gear teeth. If less paint was missing, add shims on the outer mount bolt, and if too much paint was missing, add shims across both mount bolts. I thought it was interesting. This was on a starter type that was too inconvenient to pull the starter gear out to mesh with the flexplate.

[burnin oil]

Definitely check the flywheel. My 72 is down for this currently. Every tooth is torn up but the mini starter looks brand new. Once the 57s repairs gets finished the 72 gets done. It's a shame that I rebuilt the nv4500 this summer and the flywheel was good then.