The Stovebolt Site Forums The Shop Area Driveline 12v starter 6v ring gear

OK, previous owner swapped a 56' 235 in to my 49' 3600. No problem except it's now a 12v starter and with the original ring gear for a 6v starter. I'm going to have to deal with it soon as the ring gear is getting shredded as I'm sure the starter bendix is too. Where's the best source and correct ring gear needed? to match the 12v starter?

http://devestechnet.com/Home/Flywheel

That explains the issue you are having. The starter's gears are not easily interchangeable between 6 and 12 volts. If you have a 6 volt starter, you have 139 tooth flywheel, if you have a 12 volt starter, 168 teeth on the flywheel. Flywheel ring gears are reversible as explained in the document above. Starter parts are not interchangeable unless you are a machinist. (not sure about just turning the gear around.) It's amazing you are getting it to engage at all. Then you are destroying your flywheel over time.

I had a very similar problem, the PO had installed a 12v starter designed for the 168 tooth (6V) ring gear. I solved the problem by installing a Napa part number 244-9657, 6V remanufactured starter with the 9 teeth, 1 3/16" OD gear, ($96), removed the 6V solenoid and installing a BWD S92 ( Delco D289A) 12V solenoid ($49). The 6V starter will work with the 12V system just fine, it'll spin nice and fast. I had to re-work the copper strap. Many bolters have said that you don't need to change the 6V solenoid and it will work for a very long time. Others have said the 12V causes the solenoid to "slam" forward with a potential for damage to the starter or flywheel. Me, I just changed it out to be on the safe / sure side. Questions, PM me.

Thanks for the info. I will check into that starter. Mines still a stomp starter so now I'm wondering if it is a 6v starter after all....? Time to count ring gear and starter gear teeth to double check what's going on........ She's up on jacks for a new pan gasket so now's the time.

12V started in 1955, the 235's had stomp starters until 1959, so it could be 6 or 12V

Bill

If there is nothing wrong with the ring gear on the flywheel, I would get a starter that matches it. The 6 volt starter is actually better for the 12v application because it turns faster.

I do not know if ring gears are available or not. That is a big job to be avoided if you can. Pulling the trans, clutch, etc isn't my idea of a good time.

Story Alert! I was working with a very good friend and older gentlemen, John Erb. He is renowned for his knowledge of these trucks in the Central US. He died several years back, but before then, he was Jim Carters GO-TO guy for all AD era parts. He was THE man if there ever was one.

So we get a call from Jim Carters employee responsible for obtaining parts that Jim needed saying he was short on Flywheels. John said.. "are you sure? I just gave you 5 of them" and the kid says "yup needem". So, John and I know all the yards in Ok, KS, NE and MO and we are ready to start our 2 day journey. For two days we pulled flywheels out of trucks in muddy salvage yards with no (or flat) tires buried in the mud. We had a floor jack and some plywood and some rims to push under to support the vehicle.

Understand.. to get a flywheel, you have to pull the trans, clutch, driveshaft, some open driveline, some torque tube. We got to it and got 10 of them out in the two days and of course a trailer full of valuable other parts for Jim. Jim is THE MASTER and a very good friend. He pays fairly, and on time, and he sincerely loves what he does. Whenever John and I were in KC to deliver the goods, Jim took us out to lunch. I have nothing but admiration for the man and his operation. But at the time? DAMMIT!! FLYWHEELS? REALLY??

If you do end up needing a starter, the last time I checked, Napa also had remanufactured 6V stomp starters too, part number 244-9651 , $62..........also a part number NAE 73500 but no price listed....I'd suggest that's the cheapest and easiest way to go for your situation if you need a starter.

Well it appears I made an assumption when I saw the wear on the ring gear. I have a 168 tooth ring gear and a 9 tooth starter so what I must be seeing is 60+years of wear on the ring gear. It engages and starts just fine so I will just run with it for now. At least I know where I stand with it going forward!

I think that both the 6v and the 12v starters had 9 teeth.

I think the pitch/size (?) of the teeth differed.

Would someone please correct/confirm this?

Thanks,

The numbers(of teeth) are the same. The diameter of the "bendix" gear is different(same for the shaft diameter) So the "pitch" of the teeth is different. The outside diameter of the 12 Volt gear ring(on the flywheel) is larger. The location of the starter is the same for 6 Volt and 12 Volt bellhousings. The starter gear is smaller in diameter to make up the difference. The trick is to match the starter to the flywheel. Both the 6 Volt starter and the 12 Volt starter work on 12 Volts. Only the 6 Volt starter will work on a 6 Volt system. If you have a 6 Volt truck, you need a 6 Volt flywheel and starter. If your truck is 12 Volts, then a 6 Volt flywheel and a 6 Volt starter will work. Of course the 12 Volt flywheel and a 12 Volt starter will work as well. Since the flywheel is a PITA to change, I just match the starter to it. And all is good. But I am running a 12 Volt system so I can use what matches.

If it helps - my 6V starter has a 9 tooth gear that measures roughly 1.188" and the shaft it rides on is .563".

Well shucks, I'm going to have to pull the starter again and measure the pinion!

Both starters have a 9 tooth gear- - - -the difference is in the diameter of the pinion gear and the diameter of the armature shaft. The 6V shaft is noticeably larger than the 12V, so the starter drives do not interchange.
Jerry

I haven't pulled the starter again to measure the pinion but I'm thinking what I assumed all along to be a 12v starter is actually a 6v. Since the conversion and engine swap was done by a PO it has been a reverse engineering process. I do know for sure I have a 168 tooth ring gear which means I need a 12v starter. The wear pattern I'm seeing on the ring gear definately is what I would expect if a larger 6v pinion was engaging it. It's grinding the front surface and teeth of the ring gear down and not in what I would call normal wear and tear from years of use. Does anybody have a NAPA part # for a 12v that they know for sure would work. I would like to keep the stomp start but will go to a solenoid starter if I have to. It's a 56'235. I live in a rural area and we have a NAPA store and would prefer to buy over the counter.

Hy bztguy, the o.e.m. p/n is 1107634 that translates to Napa p/n WIL91013684 the reserve online price is $147.60, hope that helps.