My car is a ‘66 427/390. This summer the starter that was in it began to have issues once the car was hot. It was part #1998217 which wasn’t correct so I got a rebuilt correct 1107365 from Ron at ChevyCool.

The new starter engages on the first try (usually) but if the car does not catch subsequent tries it does not engage and just has the spinning noise, clearly not engaging the flywheel.

I tried it the new restored starter with no shims because the 1998217 had none. I then tried a variety of shims and all seem to have the same result. First try it might engage, maybe, but after that it does not. Shims from .02”, .04” and .06”. Nothing seems to work every start, every time.

The thicker shim also seems like a hard fit anyways. The nose of the starter doesn’t fit very well into the bell housing shield when I shim the starter with the thicker shims.

I had the starter tested today and it worked fine on a bench test.
The flywheel looks ok.

I can not get in touch with Ron at ChevyCool. Vm is full for many days now.

I am tempted to replace the solenoid on the old 1998217 starter I removed and just use it. At least the starter engaged.

I am wondering how to make my $400+ dollar restored “correct” starter do more than just look good.

 

starters are a very simple part to rebuild and bench test. I would double check the flywheel for missing or broken teeth.

 

The starter I took out had no problems engaging like missing teeth would create. It’s issue was the solenoid when hot, not an engaging issue.

The new starter seems like something else going on. Anyways, from what I could see of the flex plate all the teeth seemed ok but I could only see part of it with the dust shield removed.

 

then your battery cables could be to blame

 

If you know the engine flywheel ring gear teeth and the starter drive gear (bendix) teeth are good you might need to think about the proper clearance between the two items. If the tolerance is too tight the bendix teeth won’t engage properly or at all with the flywheel teeth and the starter will just spin and whine. This is neither good for the flywheel or the bendix teeth. Each item could be slowly grinding away when this occurs. When talking about replacing a starter it is very important to know it’s position, bendix teeth, relative to the engines flywheel teeth. Sometimes, you will need to use a shim to give the proper clearance between the bendix teeth and the flywheel/flexplate teeth. A rule of thumb is that there should be .030-inch of clearance between the teeth when the starter is engaged. In a pinch, a paper clip makes a great gauge for this adjustment. Simply slide the paper clip between the two teeth after you manual engage the bendix . You can also measure the distance between the flywheel teeth and the shaft the bendix gear rides on, it should be approximately 1/8” between the two.

 

Sounds like a bad drive

 

I would not trust a new “rebuild”. Not that the rebuilder or vendor is not reputable, but getting quality parts has been a real issue.

 

How do I manually engage the bendix such that it would stay extended into a contact position? I’ve pulled it out on the bench to be certain it extends and seen it work on a tester but I can’t extend it while it’s mounted to measure.

If I could do that it is nearly impossible to see once the starter is installed. I had the bell housing cover removed and I could barely see the bendix shaft. I don’t understand how one would measure the gear gap with a clip or anything nor have much success measuring the shaft to ring gear clearance.

 

Battery cables, bad drive and bad rebuild were all mentioned.

If I put the old starter back in and it works (probably would, it’s cold out) that would rule out the cables and ring gear issues, right?

If the old one works again then I’d either have a bad rebuild or shim issue, right?

Here’s my confusion tho, I tried no shims and three different shim sizes. Those four setups did not work.

So how does a bench tested rebuilt starter not work with numerous shim tries?

Seems like one would have worked if the battery cables and ring gear are ok.

One thing I want to be clear on: the first try with starting with the key, the starter engages. It does this basically every time. It did that with no shims and each of the tries with three different shims.

If it does not start - so I have to try again- or, I turn it off and try a second time, THAT is when it grinds and does not engage.

It’s like I get one shot to start. If it sits long enough to change shims I get another shot but each time like this it only works once. Even if the car starts and I turn it off, a second turn of the key and it just grinds.

 

I believe I have experienced the exact same issues you seem to be having now with the new starter.
Without making any clearance measurements I added multiple shims and tried to start the vehicle.
Sometimes the starter would engage and start the engine and other times not, and just spin and whine.
It wasn’t until I took measurements of the starter to flywheel interface, did I know what the issue was and how to resolve it
Without the measurements I was just guessing, trial and error without a good a consistent result.
I know it’s difficult to view the area but I found it very helpful to use my cell phone to snap pictures up close of the area to see what was going on.

To resolve my clearance issue I only needed to add a 0.060 in. washer under the bolt on the engine side of the starter.

 

I put a brand new heavy duty starter on my Chevy small block back in 2000.
I started the car for the last 21 years, approximately 100 times, without any issues.
Just this year I started to have random engagement issues, out of the blue as far as I knew.
At first I thought it was a weak or corroded starter solenoid so I replaced the solenoid with a new one.
After the new solenoid didn’t correct the issue I figured it was a tolerance stack up issue and I tried to correct it with shims.
After each time adding a shim I tested the starter with random engagement success.
After adding a total of four shims with random results I knew I needed to change my approach.
Not satisfied with the random engagement, I dug in, disassembled everything and took measurements.
I found out that the clearance between the pinion and flywheel teeth was too small so I needed to shim the starter to correct it.
I was able to meet the required clearance issue with one 0.060 washer shim.
During this disassembly I also inspected the starter pinion gear and saw what damage the random engagement caused.
Keep in mind the starter didn’t experience any engagement issues prior to this year.
I have attached a picture of the original and new pinion gears below.
On the left side is the original, the right side the new gear.
Notice the wear on the top of the original gear as compared to the new one.
That wear is due to the starter spinning and not engaging.
That’s what my trial and error technique caused.
Luckily for me, the fly wheel didn’t show any signs of wear.

 

There are two locations or approaches to access the starter and flywheel measurements.
The measurements can be taken from the transmission side or the engine side.
As mentioned earlier there a two methods of measurements.
Measure the gap between teeth (0.020 in.) or measure the gap between flywheel tooth and the starter pinion shaft (0.125 in.).
Since your are already trying to measure from the transmission side and having trouble I thought I would explain the other method.
Measuring from the engine side is more involved but sometimes you don’t have the option of having an inspection cover over the transmission.
This particular vehicle had a one piece steel Lakewood bell housing installed.
Either the transmission had to be removed or an alternate method for the measurement had to be pursued.
The starter was disassembled and only the starter nose/cone casting was installed.
A rod the same diameter as the starter pinion gear shaft was installed to emulate its position relative to the flywheel.
A 1/8 aluminum piece of flat stock was used to measure the gap.


Starter cast nose installed

Simulated pinion shaft and 1/8 inch flat stock measurement

 

I read all the posted comments and appreciate them.

I ended up with the old starter back in the car today. It works fine until the car is super hot which I had no issues with today. That fact that it works seems to rule out cable and flywheel issues.

So here is what I tried and found:

With the bell housing cover off I tried measurements. I cannot measure the bendix gear gap from the flywheel so I took one from the bendix shaft to a spot on the flywheel with the old and new starter. They seem very close.

So, I started over with the new starter and no shims. That is how the old starter was set up.
No start. Not even the first try which sometimes worked before.

I then tried systematic spacers again but today I also tried just one washer spacer on the block side. No combination seemed to work.

I then noticed the new starter, when bolted in place, had a gap to the bell housing more pronounced than the old starter.

My pictures show the new starter with the bell housing cover on but that is a very thin sheet metal item. The picture with the bell housing cover off is the old starter and it sits at a different angle I believe, even considering the flywheel cover is off.

There seems to be an alignment issue the new starter has such that the nose of that starter does not sit as close to parallel to the bell housing as the old one does.

What I’m trying to describe it that the new starter seems to be at an angle so that when the bendix goes to engage it approaches the flywheel at an angle, albeit a small one, but more of an angle than the old starter when it’s bolted in place.

Once I saw this difference I just put the old starter back on and it cranks right away.

I wonder if the restored starter’s bolt seat was milled or there is a slight alignment issue with the way the bendix nose piece sits in the starter.

I may just order a replacement starter from Zip or somewhere and see how it goes in. Maybe something is off on the restored starter.

old starter bolted up, cover plate on


New starter bolted up, note cover plate off tho


closer look at the new starter bolted in place

 

I still think it is the starter drive. I would ask the rebuilder to send a replacement drive. The colder the weather the easier it is for the drive to slip.

 

I don't see any wear on the drive top. If you mean the one on the left has a lip at the top, that is because they are two different style pinion gears. Early and late design. If there was that much ground off of the pinion the flywheel would show it, but as you said, the flywheel looks good.