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parts needed to switch to auto trans

Discussion in 'Jeepster Commando and Commando Tech' started by BSW, Nov 3, 2006.

  1. Nov 3, 2006
    BSW

    BSW New Member

    Seattle, WA
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    Can anyone list what parts would be needed to switch from the 3-speed to a TH400?

    I plan on using a buick transmission without the adapter.



    I case anyone's interested, here's a few pics of the Commmando in pieces.

    Slowly grinding away the rust scale on the frame, will pull the engine next week and send it off to be rebuilt.
     
  2. Nov 3, 2006
    Pack Rat

    Pack Rat Old Timer

    I live in a...
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    Re: parts needed to switdh to auto trans

    If you were to have access to a complete partster with the auto setup that'd be the way to go. If not then you will need;
    Tranny/transfercase adapter
    Adapter for the tranny mount
    Longer shifter for the TC
    Floor mounted tranny shifter-stock or aftermarket
    Front and rear driveshafts
    Either a rad with a tranny cooler or external mount cooler
    Wire harness and switch assembly for the tranny kickdown or you could just manually downshift.
    Vacuum line for the modulator valve
    Longer speedo cable
    Good thing is the cross member is the same and the threaded holes, which are farther back for mounting it are already there. Probably filled with dumdum. You may or may not have to run a tap through them to clean them up. I've only done one that had to have the threads cleaned.
    That's about all I can think of right now but I've only had my first cup of coffee so I might have forgotten something.
    One quick question on the tranny you're using, how long is the output shaft? If you're not sure post a picture.
     
  3. Nov 3, 2006
    BSW

    BSW New Member

    Seattle, WA
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    Re: parts needed to switdh to auto trans

    Thanks Pack Rat.

    I've had to let a few partsters go because I have nowhere to put them and so far, I have'nt found anyone who will let me buy the vehicle and leave it on their property while I pull the parts I need, so I'm most likely going to scrounge up the parts separately.

    Good thing about the Pacific NW is there are a lot of Commandos up here. Back home in Florida, they're much more rare.

    Don't have the transmisison yet, but I have one available to me for free. It's sitting in a '72 Buick GS basket-case resting on the frame in a field. I'm told its a TH400 rather than a 350, though I don't really care.

    BTW, Don't know much about automatics. Does the flywheel stay the same?

    BSW
     
  4. Nov 3, 2006
    Pack Rat

    Pack Rat Old Timer

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    Re: parts needed to switdh to auto trans

    You'll need a flexplate specific to a 225. Seen a few on Ebay once in a while. Haven't been under an old Buick for a few years but I believe they had the short tail stock/output shaft which is what you'll need. A BOP 350 would work but you'd need a different tranny/TC adapter.
     
  5. Nov 4, 2006
    BSW

    BSW New Member

    Seattle, WA
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    Re: parts needed to switdh to auto trans

    Would this save me any steps in locating parts (such as the flex plate)?

    It's a Buick 231 with a TH350 out of a car.
     
  6. Nov 4, 2006
    Pack Rat

    Pack Rat Old Timer

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    Re: parts needed to switdh to auto trans

    It would save a bit, however you'd need a different adapter if you wanted to use the D20 transfer case. 350 tailstocks are four bolt, 400's are six. I believe Advance has them.
     
  7. Nov 4, 2006
    Patrick

    Patrick Super Moderator Staff Member Sponsor

    Los Alamos, NM
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    Re: parts needed to switdh to auto trans

    The Dauntless is externally balanced, and the 231 is not. You'll need a 225 OF specific flex plate..
     
  8. Nov 4, 2006
    Pack Rat

    Pack Rat Old Timer

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    Re: parts needed to switdh to auto trans

    If you were getting it for the tranny and the flywheel then Patrick is correct. The 231's, even though a little higher displacement, don't have the same horsepower or low end torque that the 225 has but parts are a little easier to locate, especially performance parts if it's an even fire. Plus they tend to idle a little smoother.
     
  9. Nov 4, 2006
    BSW

    BSW New Member

    Seattle, WA
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    Re: parts needed to switdh to auto trans

    I definitely will keep the 225, but I am having second thoughts about the TH400. I planned on that because that's what the Commandos came with. However, I've had plenty of GM cars with V8s and TH350s with no problems, I know they're strong. Also, I've heard the TH350 robbs less power than the 400.
     
  10. Nov 5, 2006
    nyejos11

    nyejos11 Member

    Emmaus, PA
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    I have a CJ5 with 225 and a TH400 probably swaped in from a command. What do you want to know?

    Josh
     
  11. Nov 5, 2006
    timgr

    timgr Jeepin' Nerd Sponsor 2019 Sponsor

    Medford Mass USA
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    The TH350 might be slightly more efficient, but I think you can find the nailhead TH400 with the right tailshaft and Dana 20 adapter with the BOP adapter ring for less than the commercial TH350 adapter. The payback on the more efficient transmission might take a long time to realize, if ever, depending on the number of miles you plan to log.

    Try your local Jeep/4WD forums, or the Wagoneer/J-truck forums.

    You'll also need the Jeepster front drive shaft with the center bearing (pillow block? pillow bearing?).
     
  12. Nov 5, 2006
    greenjeepster

    greenjeepster New Member

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    Not all 231s are internally ballanced. The early ones where odd fire externally ballanced just like the 225s. My 71 has a 231 in it pushing the th400. I don't think you can use any th400 out of any car though. You need one from a jeep as the jeep th400s are geared lower than the 400s that where put in everything else.
     
  13. Nov 6, 2006
    BSW

    BSW New Member

    Seattle, WA
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    I have no big preference betweeen the TH350 or 400. I understand that the 350 (stock) will give slightly better accelaration because it's more efficient. My biggest concern is having to scrounge-up as few parts as necessary, so I want to stick with a BOP transmission if I can. I would also like to get as many parts as I can from on source.

    There's a guy on Craigslist selling a '64-'67 Buick 300 V8 with a "Super Turbine 300" 2-speed automatic. He says it's good for a Jeep conversion as it hooks up to the 225.

    I did a little checking, and this tranimission was used in GTOs and was the predecessor to the TH350/400. Probably is strong enough. And rebuild kits are available.

    That it hooks up, I don't doubt, but I wonder if it's any good as a Jeep transmission with only two speeds?

    Anyone know about this transmission?

    Here's the link: http://portland.craigslist.org/clc/pts/230274087.html
     
  14. Nov 14, 2006
    BSW

    BSW New Member

    Seattle, WA
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    I've read the TH400 weighs 15lbs more and uses 45 HP to operate versus 30 for the TH350. In other words, if I use the TH350, I gain about 15 HP and shed 15 lbs over the TH400.

    Being that I'm keeping the 225 V6, the TH350 is more than strong enough, but is the 15 HP performance difference noticable?

    I recently drove a Commando with a fresh engine rebuild and the TH400. It was a dog. I've only ever driven manual Commandos before, but the difference was huge.

    BW
     
  15. Nov 14, 2006
    w3srl

    w3srl Jeepless in Pittsburgh Staff Member Sponsor

    Pittsburgh, PA
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    Stay away from the "super Turbine" and the "Jetaway" 2-speed transmissions. There ar elots of folks who mistakenly think that they are simply a Powerglide with a BOP bolt pattern, but they are not. Parts are scarce and $$$ when you can find them. A two-speed also isn't going to have the lower 1st gear that a TH350 or TH 400 will.

    Since you're going to a LOT of trouble to do the conversion in the first place, why not do it right the first time?
     

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