1940 Starters -- Information needed.

Jon BJon B Posts: 7,165Administrator
edited July 26 in HUDSON
Can someone knowledgeable in 1940 starters please answer a question?

I need to replace my barely-working 1937 starter (MAB-4075), and have been offered a 1940 eight-cyl. starter (MAB-4103) by a friend, which I'd like to use.  The price is right.  [NOTE: I incorrectly called this out as a 4003, earlier.]

The 4103 seems to be a perfect fit, and most of these pre-War starters are interchangeable.  (Right now I have a borrowed 1941-7  #MAB-4100 in the car, for instance, and it works perfectly.) Yet according to the 1950 interchange manual, the 4003 won't interchange with any other year of Hudson.

Does anyone know why?

I am reluctant to just bolt it into my car to find if it works, because it it's not right, maybe I'll damage something!

(Also: it is missing a solenoid.  That too is supposedly a one-year-only, and I'm wondering why I can't just use the solenoid off my '37?)

I will be grateful for any advice. I'd really like to use the 1940 starter I've been given.  Maybe someone with a Hollander interchange manual can discover that the 1940 does interchange after all!


  • GeoffGeoff Posts: 3,935Senior Contributor
    Mechanically they are a bolt-in.  The difference is most likely the position of the solenoid.
  • bob wardbob ward Posts: 1,168Senior Contributor
    AFAIK from the early 30's to the end of the splashers (both varieties) the essential engine dimensions re mounting a starter didn't change.
    All the back plates are the same i.e. the starter position, the size of the starter hole and the bolt hole centres never changed.
    The flywheel diameters are constant as are the number of teeth, the distance from back plate to flywheel never changed, the size of the starter pinion and number of teeth (9) is constant.
    The myriad of different model numbers is largely to do with the makers keeping track of exactly what they made. Every time they moved or changed the type of solenoid or tweaked the bendix arrangement, varied the coils or brushes etc that created a new model number.

  • Jon BJon B Posts: 7,165Administrator
    Thanks, Geoff and Bob.  You're validating my reasoning on this matter.  The only major difference I can see between a lot of these starters, is the thickness of the mounting plates.  And in my '37 that is important, because the threaded mounting stud is embedded in the motor plate / bellhousing, and the threaded portion that protrudes (for mounting the starter) is very short.  So I'd need a starter with a thin plate (which the 4100 and the 4003 have).
  • bob wardbob ward Posts: 1,168Senior Contributor
    From memory the starter motor bolts are somehow sandwiched between the bell housing and the engine back plate. A PITA to fit longer bolts.
  • GeoffGeoff Posts: 3,935Senior Contributor
    Methinks you are making a mountain out of a molehill Jon. Bolt the darn thing and see if it works. 
  • Jon BJon B Posts: 7,165Administrator
    Yes, but it's my mountain and I'm making the most of it!
  • allanallan Posts: 202Member
    1940 used a different circuitry for the starter.  instead of offering 6v to the solenoid a ground was offered instead.  Perhaps this is why it is a 1 year stand-along starter.
  • GeoffGeoff Posts: 3,935Senior Contributor
    So a simple swap of the solenoid is all that is required.   Go for it Jon!
  • Jon BJon B Posts: 7,165Administrator
    So, as K. Dancy suggested in another discussion, it merely depends upon whether the solenoid requires that the starter button go to ground ("earth", excuse me!) when depressed, or supply 6 volts of power to the solenoid.  Correct?  Thus, all I have to do (to make the 1940 starter work) is to bolt my old 1937 solenoid onto it.

    Seems simple enough.  Why, even I could do that!
  • GeoffGeoff Posts: 3,935Senior Contributor
    The wheels of understanding grind on!
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