Starter Grinds Up Flywheel

[amsimonsjs]

Hi everyone,

I have a twin Mercruiser 5.7's in my 1993 Maxum.

My starboard motor is having problems with its starter. This morning, it started up just fine.

When I crank the ignition, you hear a loud grinding sound, like the gear on the starter is grinding up against the flywheel.

I pulled the starter out, checked it, I found that the top half of the gears on the starter were severely worn and ground down. The lower half was intact, meaning the starter wasn't engaging fully, only halfway.

I checked the teeth on the flywheel when I pulled the starter out (I didn't crank the engine over, I just saw the position where I removed the starter) and the teeth seemed a little worn, but not too bad, so I figured all I needed was a new starter.

I bought a brand new starter and solenoid (all in one) and installed it.

I cranked it, it cranked over for about 3 seconds and the grinding noise returned.

I have not pulled this starter out, I will do that tomorrow.

Batteries are brand new.

Also, my port engine, I can move my shift lever into forward and reverse.
On my starboard, I can only move it into forward, I cannot shift it into reverse, it binds up.

If you guys could help me out that would be great. I need to start the starboard engine since we need to drive the boat a few miles to our dock. We've been parked at the slip for two days now, while sleeping in the boat.

Any assistance would be greatly appreciated.

Thank You!

-Alex

 

[drin1932]

Re: Starter Grinds Up Flywheel

When installing a new starter you need to make sure it is shimed properly. Teeth on a starter gear are normally beveled on the top to help engagement. When you bought the starter was it new or reman. If it was a reman it may still have a weak drive.

 

[amsimonsjs]

Re: Starter Grinds Up Flywheel

There are no shims that go between the starter and the bellhousing. The starter bolts are perpendicular to the shaft, so I'm guessing they have the proper spacing.

I'm not sure if its reman or new, I'd have to check. I believe it's new though.

Thanks!

-Alex

 

[cr2k]

Re: Starter Grinds Up Flywheel

You must also use brand new bolts EVERY time you remove and reattach the starter. The bolt have an interference shoulder in the block to keep the starter aligned and immobile.

Best thing is to pull the starter and have someone bar over the engine while inspecting the flywheel. Mark it so you know where you started.

If you are luck you may find a spot that is the problem and can file it out.

That reverse thing is probably your short (lower) shift cable. Or it could be corrosion in the cavity behind the shift slide in the bell housing.
Both common.

 

[Bondo]

Re: Starter Grinds Up Flywheel

Ayuh,... You changed the starter, but the Ring Gear is Trashed,...
They work with each other, the Bad ring gear will just continue to eat starters, til you replace the ring gear...

I'd also guess the shifting issue is the lower shift cable is siezed, or binding Badly...

 

[amsimonsjs]

Re: Starter Grinds Up Flywheel

I'll give the flywheel a good look today, to check for broken teeth, etc.

How difficult is it to change the ring gear?

Could this also be an electrical issue? i.e. not enough juice?

Also, keep in mind that this issue came up from one hour to the next, it was fine in the morning, and when we went to fire up the boat in the afternoon, I got the grinding noise. The previous owner (I just bought the boat) said the starboard starter was brand new.

I'll post some photos later tonight of the gears on the starter. Its only worn halfway, meaning the gear wasn't engaging fully on the flywheel.

Do any of you guys know a thread about changing the ring gear?

About the shifting issue- It was working just fine yesterday morning, why would it bind up like that all of a sudden?

Keep in mind that I'm trying to shift while the outdrive is tilted up and the engine is off. However, the port engine can shift in and out of gear just fine with the engine off and outdrive up.

 

[bruceb58]

Re: Starter Grinds Up Flywheel

Keep in mind that I'm trying to shift while the outdrive is tilted up and the engine is off. However, the port engine can shift in and out of gear just fine with the engine off and outdrive up.

Huh! So how does it shift with the engine down and running?

 

[Silvertip]

Re: Starter Grinds Up Flywheel

Did it occur to you that when shifting gears the gears may have stopped in such a manner that they are not in mesh. If you have a stick shift car the same thing can happen. Stop shifting without the engine running. It is not necessary to do so and the fact that you can get away with that on one engine and not the other is has no significance. Starters do indeed "sometimes" need shimming. This is especially true after a starter has been rebuilt a gazillion times. New end housings are made god knows where so build-up of tolerances can require a shim. It is necessary on cars and just as necessry on a boat engine. The other possibility is weak shift solenoid on the starter. If the solenoid doesn't push the bendix far enough into the ring gear you get grinding.

 

[amsimonsjs]

Re: Starter Grinds Up Flywheel

The other possibility is weak shift solenoid on the starter. If the solenoid doesn't push the bendix far enough into the ring gear you get grinding.

The bendix on the old starter was worn halfway, meaning it was not engaging fully onto the ring gear. What is the shift solenoid? If its the solenoid thats attached to the side of the starter, that was replaced yesterday along with the new starter.

If not, please let me know.

Thanks!

-Alex

 

[Sparkinator]

Re: Starter Grinds Up Flywheel

When I bought my boat last year (Ford 302 5.0 HO), the previous owner had replaced the starter. On my first trip to the lake, my boat wouldn't start and the starter sounded like it was not engaging the flywheel. I would get kind of a grinding whiring sound. I pulled the starter and checked the flywheel. It all looked ok. I reinstalled the starter and it did it again a few days later.

This time, I inspected it more thoroghly and found that the flywheel teeth were ground down a little and the starter gear was dinged a little. I don't think my starter gear was engaging my flywheel teeth fully. When I reinstalled the starter this time, I made sure and pushed the starter as close to the block as I could before torquing down the bolts. I haven't had any trouble since.

I keep a socket and breaker bar in my boat to bump the crank if I hit the bad teeth on my flywheel when trying to start the boat, but haven't had to use it yet.

 

[fishingman220]

Re: Starter Grinds Up Flywheel

i dont know how to put links up to other posts but i had he exact same problem last year.look up a post called Flywheel....... i think????? it was mine from last year, i hope this is not your problem but it kinda sounds like it.