DIY Modern starter

[squidtone]

I converted my Jeep to 12 volt for budget reasons and I'm still using the old stock Autolite starter. It's the original CJ3A "kick" starter. It does work but it's definitely got a crusty bendix and I do get gear stripping. I'm sure running faster than designed isn't helping. I've investigated rewound Autolites as well as the modern aftermarket "hi torque" starters offered by several vendors. They are both rather high dollar. The modern starter intrigued me as it appears they are common Denso OffSet Gear Reduction (OSGR) starters with adapters for our old engines. Other Denso starters are relatively cheap and I can't reconcile why a simple adapter would triple (or even more) the cost. Since I like odd projects, I thought I'd try to adapt a Denso myself.
After researching loads of different Denso OSGR starters, it appeared to me that a Denso used for Harley Davidson Sportsters would be readily adaptable. It's got a 9 tooth pinion and the front housing looks easy to slap an adapter plate to it. They are also less than 60 bucks on Amazon.
I was all set to buy one but while perusing my local swap meet, I chanced upon a Power Master (3rd party "hot rod" 'Hi torque" starter manufacturer) #9504 starter meant for small block Fords. I bought it for 20 bucks. These starters are also of the Denso design. The biggest problem was it was an 11 tooth pinion. Not a big deal as they are replaceable. I scoured the internet and found a 9 tooth Denso pinion on Walmart.com of all places. It was $14 dollars to my door. I took the starter apart and swapped the pinion gear. I also got rid of the Ford adapter.

[squidtone]

I made a load of measurements and decided this Power Master unit was adaptable. The nice thing about the original Willys mount is that the drive axis of the starter is in line with the mounting bolts. It was simple to design the flange mounting holes and center hole position...they're all in line. I looked up the recommended spacing of the end of the pinion (at rest) from the ring gear and they recommend 0.100". With the front housing of this #9504 starter my adapter could be made from a 0.500" thick aluminum plate. One small glitch was the index ring which fits into the engine plate to precisely fit in place: To make the index feature would require a thicker plate. I didn't have anything thicker than 0.500" so I decided to use six 0.125" dowel pins arrayed in a circle to fit into the engine plate bore. It worked great.

[squidtone]

The Ford adapter on this starter was held on by a tapered ring so that it could be clocked at any rotation...I didn't need that so I made two counterbores in my adapter for the two existing M5 screws that pass through the front housing and go into the main starter body. I thought these would not be enough so I put two more closely spaced counterbores in my adapter and drilled and tapped two additional tapped holes into the front housing. In these pictures I have the "extra" M5 screws installed, and in the second picture you can see where I added the tapped holes in the front housing.

[squidtone]

Ludicrously enough, I need longer length M5 screws to accommodate my adapter so I can finish re-assembling the starter, but for the life of me, I cannot find M5 x 50mm screws locally, so I have to mail order them. Sheesh.
In the meantime, I installed the adapter (with only two screws for now) onto the front housing, then installed it onto my frozen L134 to check fit. It's convenient to install just the front housing because you can push the pinion with your fingers to mesh the pinion to the ring gear and check fit. The fit seems very good.
I forgot to mention that I'm very lucky enough to have acquired a crusty ancient CNC benchtop machine, and I made the adapter on that. The adapter is a simple affair however, so I don't think it would be that expensive to get made. I'll share the drawing if anyone wants it. The thing is, I still think it would be easier to get the Harley sportster version....it already has the 9T pinion.

So, I'm awaiting the longer M5 screws to finish assembling this starter and bolt it onto my Jeep. Now it could be that this will be a disaster, but maybe not! I'll report back soon!

[mtnman37879]

Great work and I'd like to get the drawings. mtnman37879@hotmail.com

[Mark W.]

I went a different way. I went with a Toyota 4.2L starter.

If you have the late 3A bellhousing (with the enclosed starter and then 6) 5/16" bolt holes as used on the M-38) and you use a 129 tooth ring gear. The only modification needed to use the Toyota Starter is to open up the upper Bolt hole a little with either a rt tail file or like I did to just drill it out larger.

Cost for the Starter was $74.00 adapting it took less then 15 min.



As I was going with the optional 9.25" clutch and the Flywheels that work with that clutch all have 129 teeth that part was easy.

[squidtone]

Yes Mark good point I didn't mention that for folks who might not be aware...late CJ3A and CJ3B have the 129 tooth ring gear and can use the toyota starter. I had hoped to do that, but of course I have the earlier '3A style bellhousing.
Yours sure looks factory. Nice.

[squidtone]

MNTMN, I sent you a pdf with the wrong original P/N....instead of #9404, it should be #9504. I'll try to send the corrected pdf soon....I also corrected the number in the above posts.

As for my progress, I found some M5 machine screws of a 50mm length at Lowes(!) as my local hardware stores didn't have anything over 35mm. I got the starter bolted together and fitted it to the engine....it looks like it will fit okay, so I have to try it on my "good" engine as the test engine is locked up solid.
I purchased a NAPA ST6 starter switch too..The NAPA guys knew what it was and where it was shelved (no checking computer or books)...got it in less than a minute.
I'd like to keep a foot type starter (even though it will now be a CJ2A type electrical switch.
I will have to enlarge the hole in the firewall to fit the ST6 switch...it's giant, seemingly. Updates soon I hope.

[SteveKfl]

FYI... That looks identical to my Denso LMS250, part#16828, for 76-92 Land Cruiser V6, and it fit right in with no mods for my 129 tooth flywheel of the DJ/CJ3B.  It cost me New $69 shipped.   About a third of the weight to handle while installing too.

[squidtone]

Hmmmm,
I'm suspecting that there is some misinformation (or at least gaps in information) regarding fitting a Toyota starter to 124 tooth flywheel equipped Willys engines.
The big discrepency seems to be which Toyota starter people are talking about when they say it will fit the 129 tooth Willys and NOT the 124 tooth WIllys.
From what I can see, Mark's Toyota starter is the Hitachi direct drive type starter which is quite similar to the classic Delco starters...A big motor with a solenoid on top. THey've got enclosed snouts that support the far side of the pinion shaft.
The enclosed snout will fit the later 129 WIllys engine, but NOT the earlier 124 tooth Willys engine. That makes sense to me. The 124 tooth Willys can only fit open snout starters.
But some years of Toyota starters do use the open snout Denso offset gear reduction starter. I looked up a starter for a 1986 4.2 staight six Toyota Land Cruiser and it is indeed a Denso offset gear reduction starter with open snout. That design should fit the 124 tooth Willys no problem. That particular Toyota starter also has the correct pinion stickout (0.79") relative to the mounting surface which will work with the 124 tooth Willys engine.
The only other two potential sticklers that I don't have measurements on is the Toyota open snout index size....will it fit into the 124 tooth engine plate hole? The 124 tooth engine plate starter hole is 3.125" in diameter. I haven't been able to find how big the Denso Toyota index feature is.
Next is the flange mounting holes bolt spacing....If the 129 tooth and 124 tooth mounting flange spacing is the same, then it stands to reason that the Toyota flange bolt holes spacing should fit the 124 just like the 129 tooth with just a little hole shaping....
If anyone has info on the Toyota Denso index bore size, and if the 124 and 129 starter flange spacing is the same, these would help confirm my hypothesis...

[SteveKfl]

I'm not sure what "gaps" you are referring to.  Per my research notes Feb 2013, starter is mounted and in storage now, my DJ starter location measured 4.25" with 1/2" mounting holes.  I test fitted back then, the spacer plate "locator hole diameter" perfectly the same fit as the original starter.  Now my notes also indicate, that the LC part #16224 from 65-82 would fit the 124 tooth ring gear.  (My part# used 16828 was for the 4.2L six if that is a difference.)  I don't have either of those to verify that  fitment.  My notes also indicate that the 124 tooth ring gear was said to be 12 3/8" diameter, while the 129 tooth gear is 12.9942".  It seems the "spacer plate" locates the starter to the ring gear per the bellhousing in use.  I hope that may close any "gaps" my comment may have provided, and/or will help with the comparisons of the 12V starters. 

[SteveKfl]

Sorry, I'm tired and forgot to mention two things.  I have pics but can't post them, but if someone that can post wants me to email the pics to them, let me know.  The other thing is that I know of someone that bought a 46 CJ2A with a reduction starter on it, no idea of the details with it, but it works.  Now, when referencing "indexing", I have seen some models with "multiple mount locations" for various fitments.  The CJ2A has the solenoid "indexed" right up against the block, which I would think 'heat wise' is not a good thing.  His is also still a 6V system, I think has a 96 tooth ring gear, so there are options out there, it is trying to find them that hurts... and/or takes time and patience.  Good Luck!

[squidtone]

Thanks for taking a look at your notes.
There are "custom" offset gear starters available for all versions of the Willys engines...but they are typically very pricey! Hence the search for off the shelf "close enough" starters.
My addition to what you state (From what I have found out myself since my last post) regards the differences with the 124 tooth and 129 tooth Willys engines:
The 124 tooth uses a 3.125" register size for the starter and 4.500" hole to hole flange spacing.
The 129 tooth uses a 3.250" register size for the starter and 4.250" hole to hole flange spacing.

(The specs above are from only one source....I am trying to confirm with more sources)

So, those two differences will not allow the Toyota starter to work with the 124 tooth engine; one would have to mill the register diameter of the Toyota starter nose to the 3.125" diameter, and also slot the flange holes.
But, I can say the tooth pitch for both the 124 flywheel and 129 flywheel are the same, and, the at-rest spacing of the pinion gear to mounting flange for the Toyota starter, 124 tooth starter, and 129 tooth starter are the same.

So, ultimately, I would say the solutions available for us 124 tooth flywheel owners are to modify something (Like I'm doing with this Powermaster unit), or buy one of the custom ones available already.
I have emerged from my wandering into the weeds and I hope to try my starter in the next few days!

[squidtone]

I'm happy to report the Denso conversion starter works.
Hookup was easy: For testing purposes, I just took the easiest route for all my connections just to make sure it all works. I had already installed a Ford type solenoid into my Jeep so I didn't need the solenoid function of the Power Master Denso unit, so I installed a jumper wire to connect the solenoid and battery post of the starter; it now functions as if there was no solenoid in the Denso. I intend to put in a CJ2A floor starter switch, but for now, it's easiest to use my ignition switch to activate the starter, (the universal aftermarket switch I have has a "start" position unlike the original two position CJ3A ignition key switch which was long gone). So, I already had a starter wire going from my ignition switch to the Ford solenoid "S" lead. The "S" lead activates the solenoid and sends 12 volts to the Denso.
I had to install the battery cable onto the starter before installing it to the engine as the 12 volt post is, unfortunately,on the engine side of the starter housing. Not enough room to install the cable with the starter in place. Not a big deal (but a good reason to go with the Harley starter!)
The starter is waaay lighter than the autolite, and shorter too.

[squidtone]

The battery cable I had was too short for this starter so I did a temporary "bubba" mod by screwing on a piece of copper sheet to extend the cable....
Note the "loose" wire hanging off the solenoid....it's the "I" ("I' for ignition lead wire) that goes to the coil to give a full 12 volts during starting mode (bypassing the ballast resistor). I unhooked it because the junk Echlin solenoid malfunctioned and the "I" terminal no longer switches on and off with the solenoid...it's got a a full 12 volts at all times. Sheesh junky stuff. I may take it apart to see what happened....
The engine starts fine however despite the coil being deprived of a few volts during start....
But anyway, I tested the starter by unhooking the coil and running the starter to see how it sounded. It sounds great! Perfect meshing and no stripping or clashing. I connected the coil and it starts up perfectly. Even with my low operation time, it's strange being able to start it without moving my foot way over on an angle to press the starter rod.
So that's it....thanks.
Dave