A lot of Willys Jeep enthusiasts have problems getting their Jeep to start. This could be for many different reasons. But unfortunately, more often than not I see people misdiagnose their Willys Jeep starting problems. These people will sometimes try to fix problems that aren’t there. Well, it ends today Jeep Community. We’re going to address and hopefully fix all of your Willys Jeep starting problems.

Carl Walck, Willys Jeep starter drive

The most common problem that I see with Willys Jeep starting problems is that starting components are mismatched. It happens all the time. Especially if your Willys has been pieced from several different places or you have a Jeep in a Basket. For example, you might have a CJ2A but your engine and drive-train components might have come from a CJ3A. If you’re shopping for willys jeep parts and buy starting components for a CJ2A, you will almost certainly have problems with your CJ2A starter because they match the model of your vehicle, but not the engine.

TIP: when you change you Willys Jeep Starter – always change your bell housing bushing at the same time.

Adding to this problem, many starters don’t have number tags or other identifying marks so you usually have to figure out which ones you have visually.

I will make sense of the combination of critical starting components for your Willys Jeep: the starter, bell housing, flywheel and ring gear.


CJ3A, Wagon, Jeepster & Truck (1946-51)

  • or vehicles with the L&F head 4 cylinder engine
  • Autolite starter MZ4162 or MZ4137 (both are mostly the same, MZ4162 is slightly longer)
  • 124 tooth ring gear
  • bell housing is easy to identify – it has a manual linkage set-up on the top

CJ3B, CJ5, CJ6 (1952+)

  • or vehicles with F head engine
  • Autolite or Prestolite starter MDU7004 (most common), MDU7003, MDM6004 (required no bell housing bushings, integrated into nose cone)
  • 129 tooth ring gear
  • larger bell housing to accommodate larger ring gear

If you’ve ever wondered why your Willys Jeep Bell Housing has extra holes – watch this:

We hope this resolves your problems with your Willys Jeep Starter. This post should help you make sense out of these common Willys Jeep Starter Problems. It is imperative that you always know, as well as you can – all of your Willys Jeep Starting components . If you don’t you could run into unnecessary issues. But if you do, we are here to help if you need it.

Happy restoring!

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  • Bill Reiss

    Great info, Carl! As an owner of 3 Willy’s…. a 2A, 3A, & 3B it is nice to see the differences explained like this.

    This early 2A that I bought has the original starter and generator in it, but they were converted to 12 volts (huge disappointment, I know). I hope someone can convert these BACK to 6 volts for me in the future!

    Bill Reiss

  • Jay Lyon

    The Web site is fantastic! It is a pleasure doing business with a company that finally understands what it is to restore an old Jeep instead of just selling parts that “might fit”.

  • Mikealex

    Thanks for the great info. I was not aware of all the differences in the starters between the different models. Keep up the good work and keep the info flowing.

  • Fid

    One thing that can also cause hard starting is many 6 volt vehicles have had their battery cables changed over the years. Many modern cables are made for 12 volt systems and use a 2 gauge cable as opposed the the thicker 1 gauge or 0 gauge originally used in the 6 volt systems. If your Jeep has the newer cables it can definitely effect how the starter turns over. Correct gauge cables can make the difference.

  • CW4 Jerome Steber

    I have been a customer of Carl’s since the early 1980s when not may folks were into restoring Willys MBs. He has been a tremendous source of information and guidance over the years. In addition to his vast knowledge, he is an honest businessman who will not steer you wrong just too make a profit. MY congradualtions to Carl for his excellent website and recommend anyone who is restoring an antique Jeep to do business with this fine cany.

  • Ike Elliott

    I have an old model L6-226 4wd Pickup Truck Willys Jeep that I am trying to get to start.  I replaced the starter, spark plugs, and battery but it still will not turnover.  Do you have any suggestions?

  • Terry Hammon

    Thanks Carl.  This info will certainly be helpful as I begin resto on my 1949 Jeepster L Head 4 cylinder.  One question:  The jeepster is still 6 volt but has an 8 volt battery.  I have heard of this practice but wonder about possible damage and shortness of bulb life as a result. What is you opinion? Terry

  • Ken J

    I have a 1952 M38 Military Jeep with a 24 volt system on it.  The batteries are new but the starter motor when engaged turns over very slow as compared to my other vintage jeeps which makes is harder to start.  Question:  Is that normal and is it possible to speed up the cranking speed?

    Ken J

  • Roymac

    I had plenty of starter problems on my MB. It was as if the starter was dragging when engaged,  “sluggish“. Replace the foot starter switch, some of the repro starters do not “conduct“ the current as well as they should. POOR CONTACT.

  • jeepster in the woods

    Re. my “new” ’49 Jeepster,  At this point I don’t know if I have a starter, battery, solenoid or foot starter linkage problem.  I step on the switch “pedal” and nothing…This was intermittent but  now seems permanent.  Should I get some response when pressing on the solenoid button manually?  (with a screwdriver).  The previous owner, once said the linkage is old. He explained how to step on the switch and it seemed to work.  At this point I am not sure where to start. 
    Thanks for the 12volt vs 6 volt info.  I am currently working on that decision.  Leaning toward keeping 6 volt but like the idea of charging phones, running cd sounds etc.  thanks for any help you may provide.  I will install the new wire harness as soon as I figure out the starting problem. 

  • Zack B

    I have a 1952 m38 with the push rod center floorboard. Is there a conversion kit I can use a key starter or ideas to re fabricate this mechanism. Anything is helpful

  • Peter

    Hello, I have a Cj3b, when cold start: no problems, when the motor is warmed up and I want to start, he doesn’t want. Then I have to wait till the motor is cold and then I can start. Is there anywhone who have an idea of my problem? Thanks

    • carl

      Here are some ideas.

      Timing advanced too far.
      Bad coil
      Bad spark plugs and or wires. Spark plug wires need to have wire in them not carbon wire like on newer cars.
      Is carburetor out of gas or is gas leaking down into manifold from carburetor and flooding it out, gas then disapates till cooled off then will start?

    • http://www.willysjeepguide.com/ Carl Walck

      Might be

      Timing advanced too far.

      Bad coil

      Bad spark plugs and or wires. Spark plug wires need to have wire in them not carbon wire like on newer cars.

      Is carburetor out of gas or is gas leaking down into manifold from carburetor and flooding it out, gas then disapates till cooled off then will start?

  • Tubac

    Hi Carl,

    I have a 1950 Jeepster with the F head 4. From your video , I see I have an Autolite MCH 6207 starter. I was having starter problems, so I had the starter rebuilt and bought new fat battery cables and a solenoid from you. That seemed to solve the problem for awhile but now it’s back and the car won’t start. When I turn the key the ammeter dives all the way to the negative side and…nothing. For awhile, it would crank after I tapped the starter hard with a tire iron. Now, after trying it for a couple days, nothing. The battery tests at 6.5 with a meter and the ignition switch is new. I took out the starter and had the shop test it again.They said it tested good. How would I troubleshoot this?
    (Btw, very good videos here!)