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Dan’s searching for a SM420 Tower

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Dan just picked up this SM420 pretty cheaply, but it has a remote shifter rather than a tower shifter.  Anyone have a SM420 Tower they don’t need?  If so, leave a comment below and I’ll make sure Dan get’s your message.

Dan notes this tranny came from a M-561 6×6 (note inscription on serial number).  Here’s a link to Olive Drab which describes them.




12 Comments on “Dan’s searching for a SM420 Tower

  1. Brian's 58 3b

    Hey Back in town, (sunday)
    I do have a tower with the back up switch in it. Remember the problem I had when I switched out the top cover and it poped out of 3rd you will have to get the right one I will look at it on monday

  2. deilers

    Thanks Brian .. I knew you had another tower, but I couldn’t remember if it was damaged or not.

    – Dave

  3. Dan

    Thanks guys. I read something about matching top covers and was a little worried about finding one.

  4. Brian's 58 3b

    I do still have it. It is from a 1967 according to Novak. I would think this would be the best fit because the Military versions came after 67. Need the small speedometer for my 3b Trade? Daves got my email

  5. Bob

    Sounds like you’ve found one if not let me know.I have one.What do you want for your remote topshift cover? Bob

  6. Dan

    I live in Deer Park Wa. How about $50 for the remote top cover? Just out of curiosity, what do you want to remote cover for?

  7. Bob

    Would you take $40?Looking at a alternative transmission for a FC Jeep but don’t know as far as practibility.Shifting linkage is the big question.I live in western Wa.north of Shelton. Bob

  8. Dan

    I heard back from Novak. They had some interesting things to say that I thought other people may find interesting or useful. I was a little concerned that my input shaft was too long since it measured 1/8″ longer than the listed SM420 specs.

    “Thanks for checking with us regarding your 420. Yes, you can relatively
    easily convert your Military style to a “Civilian” style by simply changing
    the top cover. Your input shaft is fine, there is no need to change this.
    The top cover change, you need to make sure there is not a discrepancy
    between the third gear in the transmission and the third gear fork on the
    top cover. The easiest way to do this is make sure the new cover has a 3
    “378…” stamped on the third gear fork. So long as you go by this rule,
    you will be safe.”

  9. Dan

    Thanks everyone. I was able to purchase a standard top cover and sell the remote cover to help offset the cost a bit. Parts are starting to come together.

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