I recently purchased a 1979 F250 with a 351m engine it had not been started in about 3 years. We knew it needed a new flywheel because when we cranked on it the starter just made a horrid grinding noise and would slip off the flywheel and not start. Now we just got in back together with all new clutch, milled and new ring gear fly wheel. When i go to start it it makes the same horrid noise as before but does start up. I thought maybe it was the wrong starter so i got a new one but it is making the same noise also. Is this just how these trucks sound or what else could it be as im at a complete loss as to what it could be
Thanks for all help

 

Could be the wrong flywheel. Some flywheels (FE?) will physically bolt on and are "almost" the right diameter.
With the correct starter and flywheel you shouldn't have any "grinding" noise.

Roger Carter

 

Well I'm pretty sure it's the original flywheel we just had it milled and new ring gear and it meshes with the starter correctly

 

Well .... what kind of cars / trucks are you comparing it to to ask that? I mean, yeah .... it "maybe" sounds louder because the truck sit higher and thus sound isn't muffled from underneath and especially if you leave the sheet metal cover off the bottum of the bell housing (if it had one).

Otherwise, hard to say as I can't listen to it.
Could be a mesh problem. Maybe starter needs some shims?

 

Not to sound like an a$$, but if the starter and flywheel were meshing correctly you wouldn't have the grinding noise.

Here are some additional thoughts. Some may seem obvious, you may have already addressed them, but on the off chance you haven't...

I know you replaced the starter but the replacement might be at fault.

Are you sure your new starter is for a 351M and not a 351 Windsor?

As I remember (I think) some Ford V-8's used two different starter noses, one for a stick and one for the automatic. I'm not sure if the 351M did. They allowed the starter drive to go "deeper" into the bell housing. The wrong nose could allow the starter drive (Bendix) to hit the flywheel. You can check this by pukking the starter and looking at the rear face of the Bendix. If there is flywheel contact you will see "swirley" marks on this face.

Is the bell housing properly located by the two dowell pins?

Is the block plate in place between the bell housing and the block? The block plate locates the starter.

Hope one of these helps.

Roger Carter

 

It happens that a bad one get's shipped on occasion, no matter the supplier. Wouldn't hurt to double check the part number of the one you used even.

351 W (6 valve cover bolts) did have different starter noses between Auto and Manual as pointed out above ...
... while 351M (8 valve cover bolts) did not as far as I can recall.
I don't think the 351W was available in trucks in 1979 was it?

 

Any idea what the part number should be I have 3 different starters sitting under neath it right now 2 that seem to fit and one that I didn't seem to fit but I'm not sure which one is the correct one or if I even have a correct one

 

i think i know the same sound happened to me my problem was at one point the starter came loose if it is not meshing you will see by looking at the teeth on the ring gear weather they're chewed up or not if this is so dont turn it over unless you want to put another ring gear on it although they are strait teeth on those you should be able to flip it over and use the other side of the ring gear. But anyhow take flash light and look in the starter hole if the ring gear is not chewed up then thats not the problem but chances are it is.

 

There's a bunch, but a good start tonight would be look here at Rockauto, they have a variety of manufacturers represented. Look up starters for the 351 in a '79 which will be a 351M and for a 351 in a '84 which will be 351W (both auto and manual) and look at simularities in part numbers.

RockAuto Parts Catalog

Might confirm that you are on the right track or not?