[F ROCK]

I just converted the green '71 from auto trans to 4 speed.
i'm up to 4 shims and still grinding.
I've never used more than 2 before this.
the starter (mini) works fine but is noisy, and I can see some wear on my flywheel.
so what is the record for most shims used in one install?
digging for more shims...

[llwta76]

I've used 8 shims for years w/no issues. This is w/a OEM starter.

[4dblnkldude]

I , also have never used more than two.

[lust4speed]

Don't forget that shims come in different thicknesses. Just re-shimmed a starter for a friend and used only one - but it was a .045" thick shim to get the necessary clearance.

[David Jones]

If spacing is the issue, to a point, what difference does it make? I'd see what it took to make it work.

[77 TRASHCAN]

The factory starter on my car was shimmed a LOT, don't know how many...carry on...

[Tom Vaught]

I have used either ZERO or ONE shim as my blocks have always been Manual Transmission Coded Blocks. Auto Blocks seem to need a variety of starter shims.

So I guess I am out of the running for the RECORD.

Tom V.

[boltbuster]

Originally Posted by llwta76

I've used 8 shims for years w/no issues. This is w/a OEM starter.

Six shims here, with the same equipment...

[Cliff R]

My old 428 required so many that I made a custom thick shim and added a couple thin ones to it. Can't remember this many years later how thick it was, but it was made from a piece of flat stock.......Cliff

[Schurkey]

This surprises me just a bit.

1. I wouldn't expect much difference in the automatic- versus manual-coded blocks. If there's a difference, I bet it's in the runout or the actual diameter of the flywheel/flexplate--with the flexplate being less-precise.

2. There are a flood of "Brand New!!!" starter motors, of generally low-quality Chinese sourcing. No telling how accurately they've machined the starter motor case-to-block surface. Considering they can't get crankshafts and rods properly machined, they maybe don't even try when cutting a mere starter motor.

3. I don't ever remember an original starter with more than one shim. I have seen "half-a-shim" under one or the other bolts, to tilt the starter into or away from the ring gear.

[Formulajones]

I'm a little surprised too. I have never needed to use a single shim on any of the pontiac engines I've run. Currently no shims in the bird either with a stock OEM starter.

[Tom Vaught]

Originally Posted by Schurkey

This surprises me just a bit.

1. I wouldn't expect much difference in the automatic- versus manual-coded blocks. If there's a difference, I bet it's in the runout or the actual diameter of the flywheel/flexplate--with the flexplate being less-precise.

2. There are a flood of "Brand New!!!" starter motors, of generally low-quality Chinese sourcing. No telling how accurately they've machined the starter motor case-to-block surface. Considering they can't get crankshafts and rods properly machined, they maybe don't even try when cutting a mere starter motor.

3. I don't ever remember an original starter with more than one shim. I have seen "half-a-shim" under one or the other bolts, to tilt the starter into or away from the ring gear.

X2 on that deal.

Would be interesting to do a survey with a old GM Starter and a group of "Knock Off" GM starters and see the difference.

Tom V.

[gtofreek]

Some mini starters will actually sit the starter drive next to the ringgear, instead of under it, so no matter how many shims you put in or take out, you never make it any better. If the drive is next to the widest point of the ringgear, it won't work. This is only one reason why I don't like mini starters. They were not designed for our engines by an actual engineer. Most are just plates machined by some guy that thinks they know what they are doing and bolt it to a Toyota or Nissan starter. Some are good, but most have issues in one way or another.

BTW, When I used to do starters for a living, I have seen lots of shims in there. That's why we always called them Pontiac shims.

[geeteeohguy]

My TH400 equipped '67 GTO has needed about 6 shims with every starter it's had since 1983, which is about 3 starters. The current GM starter has been in place since 1988, and is still doing fine. My stick cars never needed any shims at all.

[Schurkey]

Originally Posted by geeteeohguy

My TH400 equipped '67 GTO has needed about 6 shims with every starter it's had since 1983, which is about 3 starters. The current GM starter has been in place since 1988, and is still doing fine. My stick cars never needed any shims at all.

Originally Posted by Schurkey

1. I wouldn't expect much difference in the automatic- versus manual-coded blocks. If there's a difference, I bet it's in the runout or the actual diameter of the flywheel/flexplate--with the flexplate being less-precise.

What flexplate are you using?

[70 bird]

Never more than 2 here?

[Nicks67GTO]

So how do you know if your starter needs shims? I dont have any in mine. 73' 455 block, centerforce flywheel, RobbMC starter. Car starts fine with no noise or weird stuff going on......should I be checking something?

[mgarblik]

Like Tom, typically blocks for manual trans. applications are much closer than those for auto trans cars. Typically 1 or 2 shims of .015-.045 total. But several factors effect this interface. Pan rail machining, multiple trips to the line hone, poor tolerance on the flex plate or flywheel and finally the machining of the starter nose cone. That's why they make the shims, thankfully. There is a way to measure what shims you need exactly, easy to do with engine out of car, not so easy with it in, but doable. I do this before installation, and the starter is quiet EVERY time. 1. Install the starter with the solenoid removed. 2. Use your hand and manually move the plunger to engage the starter drive in the flywheel teeth. 3. Use a wire gauge or a large paperclip and unbend it. Not a little paper clip but one that is about 1 1/2 inch long. The wire diameter should be .030.040. 4. Slip the wire between the starter drive tooth and the root of the flywheel tooth. 5. If it slips in, you are done, no shims. If it does not, add shims until it slips in. It's that simple. That is the factory Pontiac method and it works great. Really doesn't matter how many shims you need. Good luck.

[77 TRASHCAN]

Originally Posted by Nicks67GTO

So how do you know if your starter needs shims? I dont have any in mine. 73' 455 block, centerforce flywheel, RobbMC starter. Car starts fine with no noise or weird stuff going on......should I be checking something?

No, you would hear the problem, if you had one...