Ford 3000 Flywheel ring gear

blehmann · Jan 22, 2016

I will be splitting my 1966 Ford 3000 gasser to repair the ring gear. Fifty years of use has the teeth banged up pretty bad. I bought a new starter for it, but saw how bad the gear is while installing the starter. I am assuming that the gear can be flipped over and should be good for another fifty years or so using the other half. If this is not the case, please let me know so that I can purchase the extremely expensive 162 tooth gear prior to splitting. I do not want to leave the tractor split and on jacks for more than a day or so, preferably I will open it up and close it up on the same day. My memory is shorter than my little finger and I just don't like to let repairs linger. There are no indications that any other work will be needed while I have it opened up. The clutch is fine and there is no oil seepage anywhere except at the gasket where the hydraulic pump bolts to the block.

I could get a gear for the diesel model for $38 but the gas model gear runs $110-$190. Those extra 34 teeth are expensive!

DJ54 · Jan 22, 2016

Is the ring gear beveled on both sides..?? If it is, it should work. I've had my 2000 split a couple of times, but can't remember if it is or not.

My Dad did flip one, on one of the Super C Farmall's here, that wasn't. He flipped it, then ground the bevel on all of the teeth. It's been working fine since '75, and I use it a lot.

City Farmer · Jan 23, 2016

I flipped the ring gear on my gas "67" 4400, It worked perfect. The starter drive gear had the lead.

Soundguy · Jan 27, 2016

If its not chamfered it will wear worse, perhaps on the drive gear. Will it last a while before failure again? Probably.

New one best, but if not in the cards......

RickB · Jan 28, 2016

Soundguy said:
If its not chamfered it will wear worse, perhaps on the drive gear. Will it last a while before failure again? Probably.

New one best, but if not in the cards......

IIRC those ring gear teeth are straight cut on both sides. Also I'm thinking somebody is now offering an aftermarket ring gear after decades of OEM only at a very high price. Thinking either Sparex or A&I has the offering.

Soundguy · Jan 28, 2016

If he can get it off without killing it with heat or splitting it, and it has straight teeth, might work.

IMHO.. If I could find a good priced repop, I'd put that on. Ya know. splitting the tractor to put (back ) on a half worn out part and all.

RickB · Jan 28, 2016

Soundguy said:
If he can get it off without killing it with heat or splitting it, and it has straight teeth, might work.

IMHO.. If I could find a good priced repop, I'd put that on. Ya know. splitting the tractor to put (back ) on a half worn out part and all.

I would as well. But then what I did was replace my gas ring gear with a diesel ring gear. Trouble is, the diesel ring gear has to have a complete diesel engine attached to it.

But that strategy solved several problems. :drink:

blehmann · Apr 30, 2018

I'm bringing this thread back up for some update and maybe a little more discussion.

I split the tractor and found that someone had been into it as there was a fairly new clutch installed. Pulling the ring gear and flipping it over was pretty easy. Reassembly took a bit longer than disassembly as I was working by myself and needed to be in two places at one time in order to line every thing back up and get the two halves to slip together. I suppose that I spent most of two days doing the job. I tried the starter and found that it would not engage and not wanting tear up the good side of the flywheel I decided to take the starter to our local auto electrical shop and have it rebuilt. They called a day later and said that the starter head was cracked. We ordered a new Chinese made knockoff that I installed a couple of days later. It also did not engage properly. I pulled it off and manually operated it. I found that the lever that pushes the Bendix forward was hanging up on the housing of the stator. So I took it back to the shop and showed them what was going on. He worked on a bit and said that he thought it should work but to be sure that I have a really hot battery as the mousetrap starters take a lot of power to work correctly. I went ahead and purchased a new battery and fully charged it prior to attempting to start the tractor again. Now I have a starter that will engage maybe one out of ten attempts. Two and a half years later and the problem is about the same so I am either going to figure out what is going on or just sell the tractor and let someone else figure it out. It is not that I haven't tried on several occasions as I have pulled the starter a couple of dozen times now. I've used parts of the old starter and parts of the new starter trying to get the bendix to fully extend to no avail. Now I am pondering if I have a diesel flywheel and a gasser bendix. My memory says that the gasser has 128 and the diesel has 160+ teeth on the ring gear. The next thing to check will be to pull the starter once again and pull the bendix, then see how well it meshes with the ring gear. Any hints or suggestions are welcome.

blehmann · Apr 30, 2018

I just ran across the information. The gasser has the 162 tooth ring gear. I also found that the diesel starter has a 10 tooth Bendix. Mathematically, the gasser should have 12.65 teeth. LOL. I'm making progress!

City Farmer · Apr 30, 2018

Can you mark a tooth and slowly wrench the engine over to count the teeth on the flywheel? eBay and some tractor sites call out the same starter for both diesel and gas engines. The New Holland parts site will give you the part number you need for a gas tractor.

blehmann · Apr 30, 2018

City Farmer said:
Can you mark a tooth and slowly wrench the engine over to count the teeth on the flywheel? eBay and some tractor sites call out the same starter for both diesel and gas engines. The New Holland parts site will give you the part number you need for a gas tractor.

I pulled the starter and it is a 3139N. That is the number that pulls up for the diesel engine. Mine is a gas engine so I have the wrong starter. The correct part number for the gas engine is D7NN11001A. Both starters show to have a ten tooth pinion which makes no sense to me. I did trace the tooth pattern on the ring gear and also measured the gear on the starter. The ring gear pitch is about.2" at the bottom of the cut and the pitch on the outside of the pinion is .3". I called my starter rebuilder and he says that he has never seen anything other than a 10 tooth pinion on the old Ford starters. So, logic says that there must be a slight offset on the gas starter frame to move the pinion further away from the gear so that the teeth can mesh.

I can't for the life of me understand why the gas starter doesn't have 12 or 13 teeth on it. I went ahead and ordered a starter from Yesterdays Tractor. I tried to call but after being on hold for a half hour (on my dime) I hung up. If it doesn't work, I'll return it.

RickB · Apr 30, 2018

There isn’t room to mount a 5” diesel starter on a 3 cylinder Ford gas engine. The starter interferes with the carb. The tooth count on the starter drive is immaterial to the discussion. Tooth count and tooth pitch vary with pinion diameter which has not been mentioned. Ring gear diameter whether gas or diesel is a constant so the ring gear tooth count is relevant to the ring gear tooth pitch.

blehmann · Apr 30, 2018

RickB said:
There isn稚 room to mount a 5 diesel starter on a 3 cylinder Ford gas engine. The starter interferes with the carb. The tooth count on the starter drive is immaterial to the discussion. Tooth count and tooth pitch vary with pinion diameter which has not been mentioned. Ring gear diameter whether gas or diesel is a constant so the ring gear tooth count is relevant to the ring gear tooth pitch.

All that I am going off of is that a 3139N shows as a diesel starter on several websites that I visited. When I check compatibility the gas engine does not show up for that starter. I haven't measured it.

I agree that the ring gear diameter is constant and that the tooth count will change(or should) the tooth pitch. I cannot find any information about the pinion diameter on the so called gas starters. I find that rather maddening. Even a guy that has been in the starter and alternator business for forty years is puzzled about what Ford did on this particular tractor. If you have the dimension for the gas starter pinion, I would sure appreciate knowing it.

Ultradog MN · May 8, 2018

I have a couple of NOS gas ring gears here.
Would sell one prettty reasonable.

blehmann · May 8, 2018

Ultradog MN said:
I have a couple of NOS gas ring gears here.
Would sell one prettty reasonable.

Thanks, but that won't be necessary. I flipped the ring gear and the teeth are good now. I just walked in to the house for a cool drink after I installed a new starter that arrived at noon. The thing cranks and starts great now. I'm pretty sure that the old starter, and the new starter a year and a half ago had the wrong pinion in them. I just eyeballed it when I put the new one in today and really could not see that it looked smaller, but it works, so good enough.

City Farmer · May 9, 2018

blehmann said:
Thanks, but that won't be necessary. I flipped the ring gear and the teeth are good now. I just walked in to the house for a cool drink after I installed a new starter that arrived at noon. The thing cranks and starts great now. I'm pretty sure that the old starter, and the new starter a year and a half ago had the wrong pinion in them. I just eyeballed it when I put the new one in today and really could not see that it looked smaller, but it works, so good enough.

Happy to hear you got it back together and all is well. If the drive gears are the same and the ring gear OD is the same like Rick B said, there has to be a center difference between the diesel and gas starters. There’s no way you’re meshing 2 gears with a different diametral pitch and having them last very long.

Maybe theres a tooth profile change to make it work but there’s a difference somewhere. You cannot add more teeth to the ring gear and keep the same DP without additional material on the OD.

blehmann · May 9, 2018

City Farmer said:
Happy to hear you got it back together and all is well. If the drive gears are the same and the ring gear OD is the same like Rick B said, there has to be a center difference between the diesel and gas starters. Thereç—´ no way youæ±*e meshing 2 gears with a different diametral pitch and having them last very long.

Maybe theres a tooth profile change to make it work but thereç—´ a difference somewhere. You cannot add more teeth to the ring gear and keep the same DP without additional material on the OD.

I think that it has to be the o.d. of the pinion. But I've been wrong before. I would like to see engineering information on the tooth pitch on both the diesel and gas pinions. That is what I was looking for but not finding. I actually found some data for the diesel pinion but not for the gas. It would be nice to know and about the only way I know to do it is pull the new starter and pull the pinion out and then put the micrometer on it. Maybe later. I'm enjoying having a tractor that starts for now!

blehmann · Mar 12, 2019

Just for fun, I was going through my photos this morning and ran across this. All in all, the repair took several hours but was not that difficult. I still have trouble getting the thing to fire and have found that voltage goes to nothing once the starter engages. It is probably something to do with how I have the switch wired in. I just jumper a hot wire to the coil to fire it up, then pull the jumper and go on about my business. I'll find a wiring diagram someday for the switch and get things hooked up right.