The Stovebolt Site Forums The Shop Area Engine Shop Starter grinding

I suspect it will be obvious once I pull the starter but I wanted to see if anyone has had to deal with this before I get started. Gauging how big of a job it might be.

When I step on the starter, probably 6 out of 10 times it does not fully engage and makes this awful spinning/grinding noise.

I stop and try again. Usually within two or three attempts it catches and spins the engine and starts up.

I am hoping it is the gear on the starter. I have an old school shop close to my house that has been rebuilding generators, alternators, starters and water pumps for decades.

I have been putting it off because I don't want to find our it is the flywheel gear that is worn. A much bigger fix would be required.

A 50-50 shot! If you've been grinding it long enough the flywheel may be shot as well as the easy fix starter. Good luck.

Dave--GM part 1873789 1938-1954 that is the starter Drive. Chevs of the 40's has them, and they are on Epay all the time. I keep a spare on hand, as we have a 49 and 51 3100 with 1954 235 Engines--Bill

Thanks. I guess the only thing to do is pull the starter and see what I have.

I had this problem with my starter drive.I see starters all the time at swap meets where the starter drive gear is worn and damaged at the end. Mine did some damage to the ring gear but it was limited. With a new drive on the starter I have not experienced the problem again.

Thanks. I will pull the starter and determine if I want to change the drive gear or take it to the rebuild shop.

Pull the dust cover from the flywheel and inspect the ring gear teeth, then have someone engage the starter while you watch from below with a bright light. It's a lot more effective to do it that way than to pull the starter, because you can see the relationship of both gears while the starter is running.

Stovebolt engines have a habit of stopping in one of three places when they're shut off, due to cylinders coming up on compression as they coast to a stop. Those three areas of the flywheel ring gear will wear more than other spots. Also look for wear in the stomp start linkage that allows the starter to begin turning before the starter drive pinion gear is fully engaged into the flywheel.
Jerry

My truck started doing this really bad for a while. It got so bad it took several tries to get the starter to engage before spinning. I thought I might be developing a bad spot on the fly wheel and would roll the truck two or three feet forward (in gear) to engage at a new spot with no improvement. I decided the starter was spinning before the drive gear was fully extended and engaged.

I backed the stomp starter pedal out to ensure I was getting full extension on the drive gear. Then I tweaked the stomp starter mechanism on the firewall side so that it would engage the electrical switch and spin the motor at the last part of pedal depression.

This was an almost 100% successful fix and the only time it does it now is right after I tell someone "It starts right up every time" *GRIND!!*, or starting it up to leave a car show *GRI-I-I-ND ! !*

There's a way to eliminate starter gear grinding altogether, but it involves installing a magnetic solenoid inline with the battery cable. Push the foot pedal all the way down to engage the gear, then push a button to trigger the solenoid switch and spin the starter motor. It also adds another level of "anti-theft" protection.
Jerry

If you've worn one side of the ring gear too much (or any of the teeth in particular), pull the transmission, the pressure plate and clutch plate and remove the flywheel. Then take it to a good machine shop...preferably with an old guy still working there or at least hanging around so he'll know what to do...and have them take the ring gear off, flip it over and install it again so you'll have all new teeth on the driven side.

If you have an acetylene torch and a helper, you can do it yourself. Here is one way:

set flywheel surfaced side up on a concrete block with the 8" x 8" side facing up. Heat the ring gear with the torch but not the flywheel...just the outer part where the ring is. This might take you 2 or 3 minutes. Use a broad flame like a cutting torch but not in cutting mode. You just want to heat it well and consistently around the ring. Move the torch around and heat the whole circle. Then with a strong but blunt chisel, tap at various places on the ring gear...don't tap hard enough to chip or disfigure the teeth and keep your chisel straight and not angled. You can also use a piece of hardwood like oak or hickory. It really won't take that much effort if you've heated it correctly. Tap while your partner continues to heat and have him hold the flywheel steady in the center with a piece of 2 x 4 or something. You'll have to reach around and through his legs at times to hit all parts of the circle. Pretty soon the ring will fall off. Move the flywheel off the block and onto a flat concrete floor (remember it will be hot), pick the ring up with water pump pliers and now heat just the ring itself. Heat it pretty well but not to the point of glowing or anything. Depending on the maker it may or may or may not have a slot and tab which fit together. As I recall the 235 doesn't have one. Now flip so the good teeth are on the back side of flywheel and set it in place (line the tab/slot up if one is there). Before you set it on, second check to make certain your bad teeth are on the surfaced side now. Most of the time the concrete floor will have sucked enough heat out of the flywheel that the hot ring gear (being of course larger now) will just slide in place. I have seen people spray the flywheel with water or dump ice out of a coke cup to make sure it is cool, but you may not need to do that. The purpose of setting it on the floor is to ensure the ring only goes down as far as the back surface of the flywheel. While the ring is still hot, look around the thing to be sure it went down evenly to the floor (they almost always do). Now let it cool naturally.

I hope to figure it out this weekend. I will keep everyone posted on the cause/fix. Thanks for sharing your knowledge.

Pulled the starter from my truck(52 with a 55 235 and a 6 volt flywheel) cause the starter stopped working. Bad brushes and lots of wear on the bushings. New bendix drive and brushes along with the bushings and I was ready to go...nothing. That was how I found all the wear in the linkage. That was solved...with a cap from a soda bottle(put over the start button on the starter. Thought I was so clever. Then the grinding started. Sometimes that bottle cap would twist a bit and mess up the start point of the switch. Sometimes it would stay flat and all was well. JB weld and a flat washer cured the issue. There is not a lot of distance from engaged and start That is why the suggestion from Hot Rod matters. Get a light and look at the teeth engage. Only way to tell for sure. If you have the battery hooked up, keep your fingers out of the way. If all seems to be the switch comes on too soon(not what I would expect with the wear in the likage, but I am not looking at your truck) then you can grind a bit off the lever that moves the switch, If the flywheel is worn, then you can, with care, push the ring off the flywheel and reposition it but that is a big project. It will require the transmission to be removed, the flywheel be removed and the ring pressed off without breaking it. It can be done, just takes some care. Rotate it about 60 degrees, freeze the flywheel and then heat the ring with a torch. Drop back on and it should be fine. Like I said work.

I have a new starter on my 1949 3600 (261ci, SM420) and it grinds 1 in 20 starts as well. Is there no way to adjust the gear engagement separately from the electrical contact point? I mean other than grinding things here and there? I was reading TwoTones post and it seems to me that you can't increase/advance the pinion engagement without also making electrical contact earlier and thus defeating the pinion adjustment.

On mine I tried all sorts of goofy things: advancing the engine a quarter turn (with the fan) before starting (made no difference), eventually settling on just slightly easing off of the stomp switch if I got a grind, the spinning pinion would then completely engage and you could go back with a full stomp and start.

Rather than grind down the bump on the actuating lever (so that the electrical is engaged a tiny bit later), I might try taking off the contactor, slot out the mounting holes just a tiny bit and then remount the contactor and slide it back ever so slightly, like maybe 1/8"? What do you guys think?

Does the new starter have the correct number of teeth on it's gear?

Mike B

If the gears are not fully meshed before the motor starts to turn, you've got the pivot holes in the mechanical linkage worn oval, and/or the round linkage worn in diameter. Get the mechanical relationships correct and the problem will disappear. If you're unwilling to do that, put a Ford-type solenoid switch between the battery and the mechanical switch on the starter motor and use a push button to energize the starter motor AFTER pushing the foot pedal into full engagement. Fixing it right is a lot simpler.
Jerry

Yes, correct number of teeth on the starter gear.

Jerry, the lever on the starter that both throws in the starter gear and closes the electrical contactor is new and shows no wear at the pivot in top of the starter or where it attaches to the push rod coming from the stomp button. There's side-to-side wiggle in the lever, but there's no play perpendicular to the bearing surfaces; they all feel solid.

It might be that the little bit of side wiggle is randomly changing my contact point on the electrical contactor button, but I don't see a way to eliminate that play. Maybe try and shim it out with some thin brass washers?

I think with all the extra travel in the contactor, that moving it back a bit might be the surest fix.

Have you checked for wear internally, between the lever arm and the starter drive? There should be little or no movement of the lever before the drive encounters spring pressure that is trying to disengage the drive gear from the flywheel. It only takes a tiny bit of slack anywhere in the linkage fron the foot pedal to the drive gear to start the motor spinning before the gear is engaged. Your idea of slotting the switch mounting holes might work, but untold thousands of these starters work right without requiring any modifications. Manufacturing tolerances can stack up wrong to make yours the exception! You could also have a replacement switch that's been assembled incorrectly by a 12 year old kid in a Chinese sweatshop. The malfunction I've encountered frequently is a switch that won't run the starting motor without slipping the screw top from a Coke bottle over the push button to make it engage sooner.
Jerry

I will check for that slack and report back.

I would be nice if this thing had adjustments for the two items it's trying to coordinate: engaging the gear and energizing the starter. The fact that it's worked so well for so many decades with nothing more sophisticated than a shaped lever is an argument for the benefits of simplicity.

The grinding you hear may be the starter drive itself not grabbing due to wear. They make a grinding sound because the starter drive is slipping inside. Sounds a bit like an old starter on my 58 Chevy with the 235. I would push the stomp button down and when the starter went to spinning it would make a horrid grinding sound. Had the starter rebuilt and a new starter drive installed and it worked well for many years.

Chevy kept the Stomp starter all the way to '58? I figured they switched when they went to 12v. When did they get rid of it?

Don't know, but the stomp starter was standard in small '59 GMCs with 270 engine. Key start was an option. Both were 12v systems.

Papadisco,
Number of teeth on the starter is the same on a 6 volt starter as it is for a 12 volt starter, but they are different and cause grinding when mismatched. You may have the wrong starter.

How do you tell? I do have a 12V upgraded system, but the engine is also a mid 50's 261, so it might have been 6 or 12V originally (and the flywheel that went with it).

There are two ways I know.
If it has a black tag, it’s 6 volt.
Red tag for 12 volt.
The other way if the tag is missing is the shaft size which the bendix is mounted on.

twotone Oh yes I know that dope feeling ,happened last Saturday at a hick town parade I went to help them with. Also grind gears for em and leak oil on their clean concrete,a friend says it wouldn't be a chevy if it didn't drip oil !! LOL. Seriously people love to see old iron out there,especially little boys I put em right up there where they can see under the hood.

Stumbled on this solution to grinding stomp starters:

Inside the little housing on top of the starter is where the big, square copper contactor resides. It's held in place by the fat stud that goes through the housing and accepts the cable from the battery. When you tighten down the nut holding on the battery cable, if you inadvertently let the stud rotate a bit it is also rotating the big square copper contactor inside the housing causing one corner to dip down. With that corner rotated down, it now actuates the starter before the full throw of the lever engaging the pinion with the flywheel.

So pull off the little housing, square up the contactor and lock it down tight, then make sure you don't twist that stud putting the battery cable back on. If you still need more throw before actuating the starter motor you can also bevel the bottom edge of the contactor as needed.