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Turbo 400 BullGear??

Discussion in 'Jeepster Commando and Commando Tech' started by DanStew, Apr 18, 2006.

  1. DanStew

    DanStew Preowned Merkin salesman Staff Member

    y buddy is thinknig bout putting a dana 18 in his commando to go along with his offset rear waggie axle. well we are trying to find out what the spline count is for a commando turbo 400. Anyone know where to get a bullgear for this swap?
     
    DanStew, Apr 18, 2006
    #1
  2. jpflat2a

    jpflat2a what's that noise?

    Dan, I might be able to help with that.
    The parts book shows 2 different gears:
    940472 18-8-40 15 internal teeth
    946785 18-8-43
    problem is book won't tell me the difference between the two; I show I have each gear, actually have 3 of the 2nd number listed above.
    Problem is D20 was used in Commando, not the 18; these would be for the 20.
    I'm not knowledgable enough to take it from there, sorry
     
    jpflat2a, Apr 18, 2006
    #2
  3. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    timgr, Apr 19, 2006
    #3
  4. DanStew

    DanStew Preowned Merkin salesman Staff Member

    Is the 400 output shaft 6 spline or differnt??
     
    DanStew, Apr 19, 2006
    #4
  5. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    15 spline. Look at the table please.
     
    timgr, Apr 19, 2006
    #5
  6. DanStew

    DanStew Preowned Merkin salesman Staff Member

    There is only one bullgear that is 23 spline. What do the manufacuters use for a swap to a dana 18? I know they have adapted dana 18 to the 400, is it a special gear only available at Advanced adapters?
     
    DanStew, Apr 19, 2006
    #6
  7. nickmil

    nickmil In mothballs.

    No, a special adapter with a standard 6 spline output to fit any of the 6 spline bull gears.Nickmil

    Edit: You can still put a Dana 18 large hole behind the stock adapter but have to put the 20 gears in the 18. Gives you a low range of 2.03-1 instead of the 18's 2.46-1 low range though. Nickmil
     
    nickmil, Apr 20, 2006
    #7
  8. DanStew

    DanStew Preowned Merkin salesman Staff Member

    My buddy already has the setup. What his problem is is not so much gearing, but he has an offset rear end and needs a center. I wish he had it geared already. And matching gears. Since i have a centered waggie rear end and that is what he is looking for. i wouldnt mind going back to a dana 18 since i still have my old one on the shelf. but i have 3.51 and his rear axle is 3.73. I thoguht about swapping gears, but then that means i have to set it up and i dont have time right now to do that :(
     
    DanStew, Apr 20, 2006
    #8
  9. greenjeepster

    greenjeepster New Member

    It is my understanding that the TH400 that is in the jeepster commandos cannot be switched from the weak dana 20 to the dana 18. The only way to do it is to get a Ford dana 20 case and put the dana 18 guts in that.
     
    greenjeepster, Apr 20, 2006
    #9
  10. nickmil

    nickmil In mothballs.

    Umm, the dana 20 is stronger than an 18 as the 20 powerflow does not go through all the gears all the time, only in low range or 4 wheel drive. You can't use a Ford dana 20 case with the stock TH 400 Jeep adapter as the bolt pattern is completely different, besides the fact the front output shaft is on the driver's side instead of the passenger side which would necessitate a new front axle to match. Nickmil
     
    nickmil, Apr 21, 2006
    #10
  11. greenjeepster

    greenjeepster New Member

    I don't know anything about the T-case accept what my commando parts guy has told me and that is that if you have the automatic transmission that you are pretty much stuck with the dana 20 T-case. I has later told that the ford 20 with the dana 18 guts would slap together and bolt in, but I guess that source is probably not real reliable.
     
    greenjeepster, Apr 24, 2006
    #11