Repairing 246 starter motor | FerrariChat

Repairing 246 starter motor

Discussion in '206/246' started by pshoejberg, Apr 16, 2014.

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  1. pshoejberg

    pshoejberg Formula 3 Silver Subscribed

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    The starter in my Dino 246 did not engage correctly. Every second time or so the key was turned I could hear a click from the solenoid but no subsequent turning of the starter motor. This could indicate problems with the solenoid switch, a bad wire or a worn down brush set. I briefly considered to buy a modern high torque starter or the Superformance aftermarket starter, but decided to give the original starter a chance. Before proceeding with the tear down I bought a new brush set, a new pinion bush and a new pinion assembly. I did not use the latter two spare parts because the original parts were in excellent condition. I also noticed that the original pinion assembly appeared to be in a better quality than the aftermarket replacement.

    This is the repair procedure in steps:

    1. Dismantle the starter motor. Keep good track of numbers and positions of various shims, washers and springs. Also note how the stator coils are connected to the brush set. I did not remove the stator coils from the housing to avoid having to align the coils on re-installation.

    I completely dismantled the pinion assembly for closer inspection, but this should not be necessary unless you observe wear indications. Removing the lock ring's for disassemble of the pinion system can be a slight challenge. I changed out the lock rings precautionary.

    2. Dismantle the solenoid. Use a high effect soldering iron and a de-soldering pump to unsolder the two coil wires and keep control of the cap orientation. Remove the lock ring carefully to release the plunger. Keep good track of the washer's and isolators. Note the severely burned contacts on the pictures.

    3. Clean all parts . Remove the paint if you plan to re-paint the starter assembly. I removed the paint with a chemical stripper and then gave the parts a very light dust of glass beans.

    4. Polish the contact surfaces and the commutator and clean all electrical stuff with a electrical cleaning detergent.

    5. Re-assemble the starter motor. Lightly grease bearings and pinion system. Have an assistant helping you when re-installing the lock ring and the lock ring retainer....this is not an easy job with only two hands!

    6. Re-assemble the solenoid. I lightly greased the plunger system with a molykote grease and greased the o-ring seals with a silicone based grease.

    7. Paint the two assemblies and make up the solenoid to the starter motor. Test the starter and, upon successful test, re-install the starter.

    Happy wrenching

    Regards Peter


    Dismantle starter:
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    Last edited by a moderator: Sep 7, 2017
    pshoejberg, Apr 16, 2014
    #1
  2. pshoejberg

    pshoejberg Formula 3 Silver Subscribed

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    Last edited by a moderator: Sep 7, 2017
    pshoejberg, Apr 16, 2014
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  3. Dino246gts

    Dino246gts Formula Junior Silver Subscribed

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    This may be a stupid question or I missed something in your description, but I've had the same kind of sound from a starter motor in other cars when the battery was bad. Did you check your battery?
     
    Dino246gts, Apr 16, 2014
    #3
  4. Motob

    Motob Formula 3 Professional Ferrari Technician

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    Nice job. You can see from appearance of the contacts inside the starter solenoid that it was probably the causing the problem. The one contact on the right side was black/burned and was making very little contact.
    Why didn't you paint the housing and cover the original black paint when you had it apart?
     
    Motob, Apr 17, 2014
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  5. pshoejberg

    pshoejberg Formula 3 Silver Subscribed

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    It's a very valid question and it's vice to look for the simple solutions first, since a flat battery will leave the same symptoms. I might not have explained the problem very clearly; The car always started but sometimes I had to turn the key several time to get the starter motor to run. Lots of power from a fresh battery bought 1 hrs after car purchase. I suspect the burned solenoid contact to be the culprit.

    Peter
     
    pshoejberg, Apr 17, 2014
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  6. TonyL

    TonyL F1 Rookie

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    Good job Peter, but I think you will regret ever bothering to repair it. I have a brand new original starter sitting on the shelf as I got totally fed up with the unit. Poor cranking & high current draw are the pitfalls

    I gave in and purchased a GR starter....what a revelation.
     
    TonyL, Apr 17, 2014
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  7. racerboy9

    racerboy9 F1 Rookie Silver Subscribed

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    I've never had an issue with the old MT42E starter as long as it was in good shape. That probably goes for most starters. I got a gear reduction starter for one of my Dinos just for fun but didn't really felt I needed it. My 24-valve comp Stratos cranks and fires up with no problems on the original Marelli.
     
    racerboy9, Apr 17, 2014
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  8. pshoejberg

    pshoejberg Formula 3 Silver Subscribed

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    Why didn't you paint the housing and cover the original black paint when you had it apart?[/QUOTE]

    Good question....basically because I'm awaiting a batch of components that's being blasted over Easter and I don't want to start mixing paint for just a starter motor. All surfaces are zinc treated so there is really no need for paint behind any edges (The paint is more or less for the sake of good looks) I plan to paint all the steel with a epoxy primer followed be a 2K flat black automotive paint. I will keep the cast aluminum in natural.

    Regards

    Peter
     
    pshoejberg, Apr 17, 2014
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  9. pshoejberg

    pshoejberg Formula 3 Silver Subscribed

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    You are most likely right and I have heard nothing else than good words about these starters. But it makes me feel good to have the original starter available and in good working order. That said it's a quite time consuming process to overhaul the starter but not that expensive. If you can re-use the solenoid and maybe also the pinion gear the only huge investment is the working time and I consider that as a free be and quite pleasure full entertainment (I know I need to get a life).

    Peter
     
    pshoejberg, Apr 17, 2014
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  10. Dino246gts

    Dino246gts Formula Junior Silver Subscribed

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    Peter, thanks for the answer. Now I get it.
    Nice job.
     
    Dino246gts, Apr 17, 2014
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  11. TonyL

    TonyL F1 Rookie

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    The rewarding part is that you learn about your car and that enriches your knowledge.
     
    TonyL, Apr 17, 2014
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  12. dgt

    dgt Formula 3 Owner Silver Subscribed

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    dgt, Apr 17, 2014
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  13. synchro

    synchro F1 Veteran

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    Excellent work by a true Dino lover.
    Thank you for sharing the details and your passion!
     
    synchro, Apr 19, 2014
    #13

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