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CJ2A with a CJ3A Starter

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jgodfrey View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jgodfrey Quote  Post ReplyReply Direct Link To This Post Topic: CJ2A with a CJ3A Starter
    Posted: 03 Sep. 2021 at 10:44am
I have an issue, and it has been staring me in the face for months and I didn't even know it.  While I have had this Jeep for 45 years, and it always had a foot starter, I had no idea that it was not the correct version.

When I disassembled for my rebuild I noticed the solenoid on the firewall, but it was not connected.  When I traced wires it went to a push button to the left of the steering wheel.  Two pictures of this below.





So when I started the rebuild process I had not yet researched the starter.  I simply had it rebuilt.  When I assembled and got everything ready for the body I fired up the engine and the starter worked perfectly.

But here's my issue, and I am sure you can spot it, but here is the starter as it sits now.



It's a CJ3A starter.

So, I bite the bullet and work out a swap for a rebuilt 2A starter.  I bring it home, go to install it, and again, I am sure you know what I discovered...  I 124 tooth ring gear.  The 2A starter is for a 97 tooth ring gear.

I have two real issues here.  First, the new body coming does not have a hole in the firewall where the 3A starter linkage would come through.  So in order to get this starter to work I would have to cut a hole in the brand new body, when what I really want is the floor button starter with a solenoid.

The second problem is of course the ring gear.  If I want to change this it means pulling the engine, hauling it to the shop that rebuilt it, and having them take this ring gear off an install a 97 tooth version.

I am totally torn.  I literally have this Jeep ready to lower the body on it, and discover this show stopper.

I can't find any good pictures of where the 3A linkage would actually come through the firewall, but I assume it is where bubba punched a hole in my old body to make it work.  It is too far to the right to be easy to reach, but the hole in the floor required to make this starter work is very discouraging.

And just FYI - the engine would need to go to the rebuilder because I don't have an acetylene torch to heat up the ring gear.

Any thoughts would be appreciated.


Edited by jgodfrey - 03 Sep. 2021 at 10:51am
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mbullism View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote mbullism Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 10:52am
So a couple quick thoughts... I took my ring gear off with a propane torch (though I may have thrown a Mapp gas bottle on it)... going back on the oven wasn't hot enough so it hit the weber while the flywheel soaked in the chest freezer.  It was uneventfully easy.



Whether or not the swap is necessary depends on the pink stuff between your ears, lol.  "Never enough time to do it right, always enough time to do it over" depends on your personal definition of right.  (Id've already had the engine pulled Wink )

ETA:  When I refurbed my dizzy I installed a piece 180 out, so that "#1" was 11 oclock instead of 5.  The easy solution would have been to just advance the wire positions... it's now at 5 o'clock Thumbs Up  (I lay awake for less than this LOLErmm )


Edited by mbullism - 03 Sep. 2021 at 11:18am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote athawk11 Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 11:20am
Those of us with a 3A could help you position the hole through the firewall and make it look original...for a CJ3A.  Of course this would require you get your old starter back.  Wink
 

 





Edited by athawk11 - 03 Sep. 2021 at 11:22am
1- 1946 CJ2A   
2- 1949 CJ3A
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Michaeltru Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 11:22am
Possible to swap bendix from 3a to 2A starter?  
Mike in AZ
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Post Options Post Options   Thanks (0) Thanks(0)   Quote athawk11 Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 11:30am
One other thought.  You might be able to find a 9 tooth drive gear, for your current starter, that would mesh with your 124 tooth ring gear.
1- 1946 CJ2A   
2- 1949 CJ3A
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jgodfrey View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jgodfrey Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 11:30am
Originally posted by Michaeltru Michaeltru wrote:

Possible to swap bendix from 3a to 2A starter?  

That was my thought too, but according to Carl Walck, he's never seen anyone do it.  That would be the easy way though.  I just would have no idea what that would take, or who could do it.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jgodfrey Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 11:35am
Originally posted by athawk11 athawk11 wrote:

Those of us with a 3A could help you position the hole through the firewall and make it look original...for a CJ3A.  Of course this would require you get your old starter back.  Wink
 

 
I certainly don't hate that idea.  But the new body already has a hole for the floor switch that would go to the solenoid.

I assume it's a matter of locating where the wood block would be mounted, and getting the 3 holes in the right spot.



You can see in this picture where the old starter linkage came through.  However, this was a straight rod with no bend in it.  So it looks like they just cut a hole to accomodate that rod, instead of the bent one on a 3A.  So it came through below where the floor switch the solenoid would have been.





Edited by jgodfrey - 03 Sep. 2021 at 11:43am
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Bruce W View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Bruce W Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 12:03pm
  You realize, of course, that the solenoid is not original, and you’ll have to poke two holes in your new body to mount it, too. Originally all of the current to the starter went directly through the foot switch to the starter. 
BW 
It is NOT a Jeep Willys! It is a Willys jeep.

Happy Trails! Good-bye, Good Luck, and May the Good Lord Take a Likin' to You!

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Oldpappy Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 12:07pm
At least you have the body off and can get to things. 

Were it mine I would have adapted to use the working starter already mounted, but since you are determined to have the CJ2A setup described your best option, unless someone confirms you can change the starter gear, is to change the ring gear. No need to haul anything to the machine shop. It is really pretty easy to do at home. As already described above you don't even need any fancy equipment. I like the idea of heating the ring in a Weber grill as the whole piece would be heated at the same temp, and you can position it close to the "work bench" ( I use a large chunk of an oak tree which I have cut flat on top). 

The important thing is having things set up to handle the heated ring and get it onto the cold flywheel quickly, before it starts to cool and shrink.

 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Bruce W Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 12:15pm
  My bbq grill is not a Weber but a Sunbeam. It’s not round but rectangular. Will it still work? Big smileLOL
BW 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mbullism Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 12:22pm
Originally posted by Oldpappy Oldpappy wrote:

...I like the idea of heating the ring in a Weber grill as the whole piece would be heated at the same temp....

My recollection is that I tried (and failed LOL) to put the new gear on with the small torch.  My oven tops out at 500F, and a half hour soak wouldn't quite get it done.  The Weber with the lid down pinned the gage at 550+ (so maybe 600F) and the ring basically fell on.   fwiw.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jgodfrey Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 12:30pm
Originally posted by Bruce W Bruce W wrote:

  You realize, of course, that the solenoid is not original, and you’ll have to poke two holes in your new body to mount it, too. Originally all of the current to the starter went directly through the foot switch to the starter. 
BW 

Ok - help me out here.  I thought I understood the configuration, but the way you describe it has me wondering.

My understanding is that you either have this type of starter (3A with lever actuated engagement to the ring gear), or you had a solenoid.  I have seen it mounted to the firewall, as in my pictures above, and I have seen it mounted to the starter itself, like below.  If all the current goes from the foot switch to the starter I assume there would be a solenoid mounted there.



The solenoid I bought is curved so it can be monted to the starter, but can also be flatened to mount to the firewall.


Let me know if I have that right.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Oldpappy Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 1:04pm
The solenoid is just a momentary switch, the foot starter on early Jeeps does the same thing as a solenoid. Having both is redundant.

Most of these old Jeeps have been converted to 12v systems, a newer ignition switch with the wire going to a solenoid instead of to the foot switch so the vehicle can be started with just the key.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jgodfrey Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 1:15pm
So, I don't need a solenoid if I have a floor switch?  The solenoid that was in it went to a button on the dash and that appears to be original.  It was disconnected when the 3A starter went in.

Help me understand the mechanics behind this.  The 3A starter uses a lever to move the bendix into position on the ring gear.  So doe the 2A starter, with no lever, push that into the ring gear without a solenoid?

I guess am not really sure why you would ever need a solenoid if you have a key that just has a run position - which is all I have ever seen in this Jeep.  You would turn the key and hit the floor starter.

If I don't need a solenoid I can return it.  I have a new floor switch, but depending on which direction I go with the current starter I may or may not need it.

I am really thinking of pulling the engine and swaping that ring gear.  It would also allow me to change the motor mounts, which I should have done anyway.

I am looking into swaping the drive gear on the starter, but since no one has seen that done, I am not sure it will work.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote WeeWilly Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 1:36pm
 It might help to think of the solenoid as a electronic activated switch and the foot switch on a cj2a as a manual activated switch. They both accomplish the same thing.  If you use a key starter switch or a dash push button starter switch you will have to use a solenoid to handle the the high amp surge at start up.

   Jim
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jgodfrey Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 1:43pm
Ok.  So pending a couple things (the ability to swap the gear on the starter to match my ring gear, or my desire to pull the engine and swap the ringer gear itself to match the starter) I only need the foot switch.

I think I got it now.  I guess the solenoid mounted to my firewall and the button on the dash were the option chosen by the buyer, instead of the foot switch.  But when that starter died, instead of getting the correct replacement, they went with what was likely available and just punched a hole in the floor to accomodate it.

Then they never took out the button or the solenoid.  They were still wired together when I disassembled the Jeep, but obviously had no where to go.

Great help from all of you - as usual.  Thanks

I will post once I figure out if I can swap that gear, etc.  It might be useful incormation for others.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Bruce W Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 1:57pm
  Originally, on CJ2-A’s, there was no solenoid and no dash push-button. The foot button switch was the only thing between the battery and the starter. It has very large contacts in it to handle the large amount of amperage that it controls. Your solenoid and dash button are a Bubba “upgrade”, very common. I don’t think that Willys (actually Kaiser) used a solenoid until the change to 12 volts. Check the wiring diagram in the service manual. You DO have a service manual, don’t you?

The drive gear is moved into mesh with the ring gear by inertia. When the starter motor starts up, the drive gear wants to remain stationary. A “screw” in the starter drive moves the gear toward the ring gear. A remote-mounted solenoid relies on the same principle. 

If you have a good quality foot switch, no solenoid is needed, no dash button, a simple two-position switch. Less wiring to give trouble. However, foot switches, like a lot of other parts these days, can be of poor quality and cause trouble. 

I’m sure that the CJ2-A and CJ3A drives attach to the shaft differently and will not interchange. 
BW 
It is NOT a Jeep Willys! It is a Willys jeep.

Happy Trails! Good-bye, Good Luck, and May the Good Lord Take a Likin' to You!

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Post Options Post Options   Thanks (1) Thanks(1)   Quote smfulle Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep. 2021 at 3:42pm
More fodder for the grist mill.
I  do not like a foot starter. When I am climbing on a steep wall and stall out, I do not have enough feet to work the clutch, brake, accelerator AND a foot starter switch. Just the clutch, brake and accelerator are tricky enough. A key switch with a start function that activates a solenoid is much handier and could save your life if you need to restart on a steep climb.
Your mileage may vary.

Here's an Instagram video of me installing my ring gear. Turn on the audio to hear me explain what I did.



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