My '79 F-250 4x4 has a 400 with an NP435 4 speed.
Since I bought it 5 years ago, I've gone through a couple of starters. I have replaced them and the fender mounted relay/solenoid/whatever it is a couple of times as well as the voltage reg.
it seems like after a few months, the starter just spins when I turn the key and I'll pull the starter to find one or several teeth worn down. This truck will often sit for several months at a time as I just use it for hauling mulch or landscaping waste.
Today I went to start it and it spun scratchily. Second time I turned the key, it went "chunk" and then whined. Since then, I can't get it to spin. I hear the relay clunk but the starter won't turn the engine. Battery is fully charged.
Not sure what to try from here. I suspect a clearance problem with the starter, but it seems like I need to turn the engine to get it off the stuck spot. Where it's parked, it can go back but not forward. I was thinking of putting it in reverse and seeing if I can move it a few feet with a tractor just to move the engine off that spot and then see if it will start normally.
Any better ideas?
And suggestions for how to solve the problem long term as well? There are currently no spacers or anything on the starter. It just bolts right into the bell housing. When I have the starter out, the part of the flywheel I can see looks fine. No chewed up or missing teeth on it.
Thanks,

Sean

 

You need to replace the flywheel sounds like to me. The teeth break off and create a bad spot. Then everything else gets chewed up until you finally replace the ring gear/flywheel.

Edit: I just read the rest of your post, Sounds like you haven't seen any broken teeth? If you need to turn the motor over by hand so that the starter will catch, I'm sure your missing teeth somewhere around that flywheel. Take a really good look at it, turning it over slowly with a large screwdriver or something.

 

No, I don't see missing/chewed up teeth on the flywheel. The starter sounds like it has "caught", but can't spin the motor. Which is what made me think it might be bound up, and if I could "move" it off that spot, it would probably turn.
I suppose it's possible the flywheel could be bent or something, but the engine when it runs doesn't have any perceptible "unbalanced" or out of round feeling to it.

 

I hear what your saying now...

I had an out-of-round VW fly wheel that would slowly chew up and spit out starters...and it was caused by someone drilling new flywheel mounting holes and trying to adapt it to the motor I had?? Dumb a$$es. Took me a while to figure that one out...

Make sure your buying the correct "new" starter (manual/auto), don't buy reman if you can help it. I believe they offer different starters for your rig, Im not sure though...

 

Thanks. I've been getting these at Auto Zone. I'm sure they're rebuilds, based on the price. I know that they ask if it's an auto or manual, but can't say for sure they're giving me the right thing.

 

when i used to have my 86 bronco, it ate autozone starters..i had 2 go bad in under a year.. they always sounded horrible..the first one ***** it's bearings/parts in my driveway, and the second one just seized up...went with a reman from Napa and the difference was day and night, it was quieter, got the engine started quicker, and as far as i know, it's still out there doing its job.

 

Good to know. I just went with the closest place. I think the nearest NAPA is another 15 minutes or so away, but if the starters last longer, it's worth it.

 

Take in your old starter to Napa and see if they can cross ref #'s and see what part you have for sure. Then compare your old starter with Napa's new and see if their are any difs.

 

I have started using NAPA for anything electrical. if you compare an off the shelf Napa starter solenoid to the better quality lifetime warranty one from Oreillys Advance etc., the napa one will weigh half again as much. we burnt out 3 oreilly solenoids in 1 year, are on our 4th year with a napa one. Had basically the same thing happen with starters...

 

Echlin is decent stuff. Been using them for years.

My guess is the flywheel or wrong starter. There are differences between the auto and manual ring gear that the starter engages. Like toof counts and starter nose depth.

If somethings out, then the parts a parts book give you might be the wrong part.

 

Edit: Yeesh, making double posts everywhere I go!

 

Worth repeating.

 

You can say that again!

 

There are still old time automotive electrical rebuild shops around that rebuild starters, alternators, and electric winches etc. .. The ones that are still in business are worth supporting and usually put out a superior product .. After all back in the day before 3g alternators to get a high output alternator you had to have one made/modified

 

I always hate when people post problems and then never follow up.
So, Saturday, I put the truck in 3rd gear and pulled it backward about 6 feet or so. When I hit the key this time, the starter wasn't stuck. Now, it spun freely, but never engaged.
I figured whatever in it causes the gear to move forward and engage the flywheel to start, and then disengage, must have crapped out. It must have died while it was engaged, and my moving the truck in gear cause it to wind its way back out. In any case, it was disengaged and wouldn't re-engage.
So, starter shot, whatever the technical reason for it.

This time, I drove a little farther, to my nearest NAPA. They had the starter, and I don't think it was any more expensive than the last one I bought about six months ago at Auto Zone. Was going to buy a fender relay as well, but they were out of it, and honestly, I had replaced it maybe last time or the time before, and juice was clearly getting to the battery.
One of the things I love about working on this truck is I can roll right under without jacking it up, and a starter install is a five minute job, if I'm taking my time.
Hopped in, crossed my fingers, hit the key, engine cranked enthusiastically, and vroom!

Now, the next test is to see if I can get more than six months out of this starter.