Ford 351W, starter clunks but doesn't spin flywheel

[ToddfromCA]

Hi all,

Looking for a little advice

The Problem

My motor was getting a little slow to turn over so I decided to take a look. Batteries were new so I cleaned and tightened all connections but it didn't improve. Pulled the starter and the drive and bendix gear were rusted bad. Problem solved, or so I thought. Replaced the starter, and it didn't start the first time. Tapped the casing with a wrench thinking that maybe the gears weren't lining up with the flywheel perfectly. Still nothing.

What I'm hearing is a loud clunk coming from the starter when I turn the key, and I smaller clunk when I ease off. To me, it sounds like the starter drive shooting out and maybe hitting the flywheel. There is absolutely no sound of the bendix gear actually turning.

Here's what I've done so far...

- tested batteries not under load and they are good at 12.8v
- tested in side of slave solenoid and get 8v under load
- tested out side of slave solenoid and get 8v under load
- tested batteries while under load and get 8v
- cleaned all connections (batt,switch,slave solenoid, starter) and tightened
- took batteries into shop and they said they're perfect
- bench tested starter and it is perfect
- bypassed slave solenoid and nothing (jump cables from batt to starter)

Here's what I'm thinking...

Seems like a resistance issue but since it happens whether switch is in the 1,2, both position, it seems like the cable doesn't matter. The only cable that is shared I believe is the one from the out side of the solenoid to the starter. I'm hoping that since this cable is low in the bilge and I do get some water in the bilge from time to time (see old starter) that salt water has wicked up this cable past the shrink tube and is creating the resistance.

I'm going to check it out but also wondering if it could be a hydrolocked motor or a poor grounding of the starter to the block (see wet bilge). I'm thinking hydroock is not very likely since it fired 2weeks ago perfectly and I just did annual maintenance (compression, exhaust)

Any help would be appreciated. Thanks

Motor is 351w with Merc Alpha 1 gen1

 

[vegasphotoman]

Re: Ford 351W, starter clunks but doesn't spin flywheel

my best guess would be bypass the starter solenoid, if it cranks fine, then that solenoid went bad.

Problem with a bypass test is you will get a spark when you attach the 2 wires together. make sure there's no fuel fumes etc

put KEY IN OFF position so the motor only cranks and doesnt start.......
Disconnect the negative battery wire, take the 2 big red wires off the solenoid, attach them to each other using a nut and bolt, put the negative on to see if it cranks......you have to remove the neg fast so keep your hand on the neg terminal

if no crank.... either the new starter is new junk under a load
.....or like you said hydrolocked (but you doubt it)

I haven't seen one go out........ but Im sure that there's the possibility! they run alot of juice thru them....etc

 

[FreeBeeTony]

Re: Ford 351W, starter clunks but doesn't spin flywheel

I would bet a bad gnd. Take an ohmmeter and measure the resistance between the negative terminals of the battery and the block. It's probably the connection of the negative battery cable to the block.......happened to me while fishing in the ocean once.

 

[vegasphotoman]

Re: Ford 351W, starter clunks but doesn't spin flywheel

FreeBeerTony thats a good call.....
it seems like he cleaned the connections and tightened, but could have missed the block connection on that ground wire

 

[boat1010]

Re: Ford 351W, starter clunks but doesn't spin flywheel

I'm thinking it's your battery. If you test the battery under load then it isn't good. Usually a "good" battery will read a little over 13 volts. I would test the battery and go from there. Just because its a new battery doesn't mean it isn't bad.

 

[FreeBeeTony]

Re: Ford 351W, starter clunks but doesn't spin flywheel

FreeBeerTony

Not FreeBeerTony........FreeBeeTony......but I think I like your version better!!

 

[ToddfromCA]

Re: Ford 351W, starter clunks but doesn't spin flywheel

Thanks fellas

I'm going to definately put that on the check list. I did give the ground to the block a look and the connection looked real good but didn't check resistance with the meter.

It is in an area that could be prone to scuffs and water intrusion. Will report back.

Really trying to get a definate solution before mounting up the starter again, I've pulled it twice already and saying that it is tough to get to would be an understatement to say the least....

 

[Bondo]

Re: Ford 351W, starter clunks but doesn't spin flywheel

Ayuh,... The Clunk,... Clink.... tells me the starter is Fine...

Put a wrench on the crankshaft,+ see if you can turn it,.... Sounds like you Won't...

If you hold the key a second or 2,+ Don't see smoke,... Your connections are probably Fine...
If they were corroded, the resistence would cause smoke under that heavy a load...
Especially if it's 2 Good batteries...

 

[ToddfromCA]

Re: Ford 351W, starter clunks but doesn't spin flywheel

Thanks for the response.

Had both batteries tested individually under load and was told both are perfect by two different shops. I've been switching my switch to "both" when starting (for test purposes only) along with flipping the emergency combiner to give me additional house juice.....still nothing?

It sure seemed like a battery issue to me as well, maybe I'll pull out a third battery and double check just to be sure. thanks again

 

[ToddfromCA]

Re: Ford 351W, starter clunks but doesn't spin flywheel

No smoke when I hold the key for 3,4, or 5 seconds.

I'll try to turn the crank after double checking my ground. Turns clockwise right?

If I can't turn it, do I need to pull some spark plugs to ease the compression?

FYI, oil looks very good and engine had been spinning like a top up to this point, even when it was a little slow with the original starter.

 

[FreeBeeTony]

Re: Ford 351W, starter clunks but doesn't spin flywheel

Hi all,

Looking for a little advice

The Problem


- tested batteries not under load and they are good at 12.8v
- tested in side of slave solenoid and get 8v under load
- tested out side of slave solenoid and get 8v under load
- tested batteries while under load and get 8v

This is why I suspect the gnd.......

 

[ToddfromCA]

Re: Ford 351W, starter clunks but doesn't spin flywheel

thanks Tony...and by the way I certainly owe you all a free beer!

I can't believe how good this forum is, 6 great responses in literally minutes. Thanks gain

I'll be checking the ground, trying to manually turn the motor, and taking some pics of the flywheel this afternoon. Will post results.

 

[boat1010]

Re: Ford 351W, starter clunks but doesn't spin flywheel

Sorry, but I still am looking at the batteries. If you were testing the voltage at the starter and had 8 volts I could see the ground being a problem. BUT if you are testing right at the battery terminal then it can not be a ground issue. The ground is just the return path to the battery negative post. So if it were a ground issue you would still be getting 12.8 V under load. I know you said that you had the batteries tested and LOL I know I have been wrong before but everything that I am hearing leads me back to the batteries. I guess I could see it knocking down the voltage if the motor is locked up. But still wouldn't think it would drop it down that much. If you test your battery voltage while you are turning over a good motor it will not drop the voltage below 12 volts. So to drop it that much even if the motor was frozen is hard for me to believe. When you hold the starter for a few seconds does the starter get warm? The dissipated voltage has to be going somewhere and it does it in the way of heat. If there is a direct short it will get the wires very hot in a very short period of time. If it is a bad ground then it should be sparking where there is a bad ground. And if the ground is bad enough then it will not be dropping the battery voltage because it isn't getting back to the battery.

 

[Bt Doctur]

Re: Ford 351W, starter clunks but doesn't spin flywheel

Either pull the spark plugs or pull the drive.

 

[Lyle29464]

Re: Ford 351W, starter clunks but doesn't spin flywheel

my money is on bond-o

 

[ToddfromCA]

Re: Ford 351W, starter clunks but doesn't spin flywheel

interesting thoughts. I haven't felt the starter with my hand but I'll see if it gets hot. Will get the third battery too, even if it means pulling the one off the truck.

 

[Bondo]

Re: Ford 351W, starter clunks but doesn't spin flywheel

Ayuh,... Put a Wrench on the crankshaft before you call out the army, man...
It don't cost a dime,+ it's an important Diagnostic procedure....

 

[Don S]

Re: Ford 351W, starter clunks but doesn't spin flywheel

I can see it coming Bondo. New starter, new batteries, new cables, new battery switch, months of time lost. Only to find the engine won't turn over, why? Gear broke a tooth in the outdrive and the piece jammed.

But just a little time to turn the engine by hand to see if it works or not is all it takes. Take the plugs out, even pull the drive to help narrow it down.

Todd .............. listen to what is being said.

 

[FreeBeeTony]

Re: Ford 351W, starter clunks but doesn't spin flywheel

If it was something mechanical, why would he only have 8 volts on the starter?

 

[Don S]

Re: Ford 351W, starter clunks but doesn't spin flywheel

Heavy load, nothing moving.