grinding starter motor

[macibell111]

I have a 6 volt starter and a 12 volt system .my problem is when I start the truck it grinds 1 out of 3 times when started,i don't know what to do at this point ,is there a way to shim it or do I take it out and change it to 12 volt,or can I find one somewhere off the shelf don't know exactly what the problem is..any ideas thanks Jack

[w30bob]

Hi macibell,

Assuming the 6v starter is compatible with the flywheel ring gear................my first guess would be the starter drive is going south on you and needs to be replaced. Some call it a "Bendix", but it's the part that springs out to engage the ring gear on the flywheel. I've seen them on Ebay from $8 to $35 and I'm sure the usual MV vendors stock them. But make sure that's the problem before you order one. It looks like this;


m37bendix by w30bob, on Flickr

Now about using a 6v starter with a 12v system.....not sure I get why you're doing that. If you end up cranking for more than a few seconds you're going to fry that starter. A volt or two over rated isn't bad, but twice the rated voltage is asking for trouble. At the very least.....keep a hand crank under the passenger seat......you might just need it.

regards,
bob

[tbone1004]

6v on 12v isn't going to hurt that motor. Yes it's spinning twice as fast but it is drawing half the current so it will be fine. These flatheads should also start fairly quickly. I know mine was in questionable shape when I got it and still has somewhat low compression *between 80-90psi. Last I checked it was 80 on all 6 but it has been driven a lot more and feels better since the valves are getting ungunked* but it still fires up with less than 2 seconds of cranking.

Starter probably just needs a rebuild. Take it over to a local starter shop and they can help diagnose it. I have a great one up by me. No real point in converting it to 12V, it will be just fine running on 6. Lots of guys have been doing it for a long long time.

[pwrwagonfire]

6v on 12v isn't going to hurt that motor. Yes it's spinning twice as fast but it is drawing half the current so it will be fine. These flatheads should also start fairly quickly. I know mine was in questionable shape when I got it and still has somewhat low compression *between 80-90psi. Last I checked it was 80 on all 6 but it has been driven a lot more and feels better since the valves are getting ungunked* but it still fires up with less than 2 seconds of cranking.

Starter probably just needs a rebuild. Take it over to a local starter shop and they can help diagnose it. I have a great one up by me. No real point in converting it to 12V, it will be just fine running on 6. Lots of guys have been doing it for a long long time.

Well said Tom...yeah my M-37 has a 6 volt starter on its 12 volt system, as do both the FFPWs I drive at work. It has always been my understanding that a 6 volt will work fine with a 12 volt system just spin faster. But a 24 volt would NOT work, or be fried.

-T

[pwrwagonfire]

I have a 6 volt starter and a 12 volt system .my problem is when I start the truck it grinds 1 out of 3 times when started,i don't know what to do at this point ,is there a way to shim it or do I take it out and change it to 12 volt,or can I find one somewhere off the shelf don't know exactly what the problem is..any ideas thanks Jack

[/quote]

You probably just have a flat spot in the starter. I bet you if you just have it re-built your problems will be over. I drive an M-35 that grinds like you say.


-T

[macibell111]

thanks everyone for the input.she is done as far as I want to take her for now, so other than turning her into a winch truck ,I will take out the starter and have it rebuilt.

[macibell111]

do I need to take out the distributor to get out the starter?

[tbone1004]

no, but be prepared for a lot of cursing and busted knuckles in the process. It is a bitch and a half to get that thing out as sockets won't get on there and you can't get the ratcheting end of a wrench on there either. It's slow going. I unbolted the oil filter from the mount to have better access putting it back in, but I don't think it's necessary. Obviously disconnect the battery first since the starter stud is the buss for the entire electrical system.