Starter to flexplate....how far into the teeth?

[SaintC]

I was cleaning up a messy tranny oil leak, and had the starter out, as well as the tc cover. I noticed that the wear on my flexplate teeth is sitting about half way. Meaning, when I hit the starter, the starter gear only goes about half way across the teeth to crank. Now, when I moved the starter gear forward, it hits a bushing of a sort that stops it from going any further.

This does not seem normal to me. It seems that the gear should go all the way across, or at least very close to all the way. The flexplate gear is not that wide that it can handle that kind of stress.

Has anyone else noticed this, and is there a way to correct it? I am thinking of removing or modifying the starter bushing so the gear can go about 1/4 or more further, but I also need the gear to retract properly.

Any ideas??? I am taking the starter to the auto store in a couple of days. The guy I spoke with said that they do test for gear contact, as well as motor output.

[da4wheeler]

Properly shimming GM pad mount starters is probably the most annoying automotive thing I've ever had to do. Disconnect the wires off of the large solenoid terminal ( so the starter won't crank). Put a one-man starter switch between the small + solenoid terminal and the battery. Pushing the momentary contact button should extend the drive gear without cranking the starter. This function can also be performed by a friend with poor reflexes touching a wire to the battery post. Large quantities of carbonated malt beverages can dull the reflexes enough to allow someone to touch the post without jerking back when they see the spark. :D Note... don't do this for too long. How to know when too long is reached? The wires leak all of their smoke and the starter doesn't work any more.

I've heard various recommended clearances, but I usually bend a jumbo paper clip straight, and make sure that it slides slightly between the drive gear and flywheel teeth. It should drag a little, but not hang up. Add shims as necessary. I believe that shimming the whole thing moves it out, while shimming only the outside moves it in. I may be wrong on this, as I have not done one in a few years.

Why haven't I done one? The trick is in the next step! After properly shimming the starter, don't just jump for joy and go drive the victory lap. Drop the starter again, clean and degrease it well, and then super-glue the shims to the top in the proper relationship. Now... if your starter ever goes out again... rebuild the one you have instead of trading it in. You will never have to shim something ever... ever... ever again.

Good luck, and if your flywheel/flexplate is really worn that badly, you may want to consider replacing it, but I would just wait until the starter is skipping teeth, because it will run a heck of a lot longer than it looks like. I've had similar looking flexplates go over 50k miles with no issues.

[britannic]

I think SaintC is referring to the fact that his starter pinion only engages half the width of the starter ring. The clearance is a different issue, I know that my 1985 didn't have shims and I didn't need to fit them for the new starter. I believe shims were required up until 1984 and part of 1985 year though?

My starter ring had the same characteristics described by SaintC when I renewed it.

[SaintC]

What you are talking about, I believe, is the backlash...or mesh. Off the top of my head, I believe what you are doing is striking the balance of a tight mesh, without the gear binding up on you.

My problem is that the gear is not going far enough forward to contact more of the flexplate gear ring.

Thanks for the tip on testing. I will use when I try to "adjust" the strike distance.