General trans?

Discussion in 'The "Juice Box"' started by Donuts & Peelouts, Aug 15, 2017.

  1. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    you need mainly a way to clean it, I hook up a hose to the water heater and crank it all the way up, rinse everything then throw all but the case into the dishwasher. still have to hand brush the case.

    Ok .Factory development ended for the 2004r in 88. aftermarket continued but at a much higher cost.
    I would like to try out one of those six speed automatics.
     
  2. TexasT

    TexasT Texas, where are you from

    I went to a local trans place that has a cleaner oven. He told me , sure, bring it down and he would put it through for $25. But I didn't even do it . I just used the purple power stuff and brake clean.

    Torque converter tech has come a long way since the switch pitch. There are plenty of good units that will stall at 3k rpm and cruise with a pretty tight slip ratio. Most aren't cheap. I am lucky. We have a place near me that does converters.

    As above the simple route is a low three rear gear and the th400. The 455 makes plenty of low power to get the car moving. But if you want tire smoking a higher ratio rear like a 3.42 or 3.73 and one of the over drives with the lower first gear will shread tires and cruise at a decent rpm too. Your rear tire height has an affect on it too.
     
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  3. Donuts & Peelouts

    Donuts & Peelouts Life's 2 Short. Live like it.

    Thanks Texas T.

    What's the theory behind the tire height?..

    Lol sorry I know one thing is explained to me and I always got another question.
     
  4. TexasT

    TexasT Texas, where are you from

    The taller the tire the more ground it covers on each revolution. This is the one thing I learned In trigonometry in hs. It is the concept of angular velocity. With any circle there is a center, a radius, a diameter and a circumference. The diameter is essentially the tire height, and half of that is the radius. This concept is that the larger the radius the faster the point on the circumference moves when the circle is rotated.


    Any way, the taller the tire the more distance you can cover with each rotation, and if your engine can maintain the same rotational speed you can cover the measured distance quicker with a taller tire. A taller tire also give a larger contact area than the shorter one and usually gives better traction as well.

    Keep asking, it is how we learn. Ill give the answers I can swing, and there are plenty way smarter than me here that are happy to answer too.
     
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  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    The ratio of a circle's circumference to it's diameter is the constant, pi, 3.14159265359. One revolution of the tire covers a larger distance with increasing diameter. It also changes the axle ratio. You can figure out how much by dividing old tire diameter by new tire diameter. Since our Skylark/GS car were originally equipped with tires that were about 26.6" tall overall, any tire that is larger diameter wise will numerically decrease the axle ratio. I have 3.73 gears, but I use a P275/60R-15 rear tire which is 28" tall. 26.6/28 = .95. .95 X 3.73 = 3.54. Using a much larger tire is the poor man's overdrive. Yardley does this, he uses 33" tires on his 69 Riviera when he goes on long distance trips.
     
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  6. BRUCE ROE

    BRUCE ROE Well-Known Member

    A little research will reveal that a tire has a "rolling diameter/circumference" which
    is not the same as measurements of that perfect circle of a tire on a shelf. That is
    because tires in use are FLAT on one side, with an effective circumference tied to
    the belt inside that doesn't change as the tire wears. I first realized that after
    calibrating the odometer much better than original. This can be taken into account
    by careful on the road measurements. Attempts to just use calculated setups will
    not be as accurate.

    I see my tach at 2000 rpm at 60 mph; good for the engine and mileage.
    Its done with a 2.41:1 axle, which doesn't prevent burning some rubber. Bruce Roe
     
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  7. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    I used my gps and from a stop , i go , and then stop when gps says one mile. then I look at my tripometer that I previously reset, and if it also says one mile. Then I know im in the ball park. Then if its off you just change the spedo gear accordingly. Thats what I do for the dudes that have the 40 inch monster chrome wheeles.

    In overdrive with my 700r4 at 2000rpm im at 78 mph. No need to instal monster wheeles. Stock Buick rally wheeles 15in. 3.07rear gear.
     
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  8. Donuts & Peelouts

    Donuts & Peelouts Life's 2 Short. Live like it.

    Thanks Guys I got it.
    Well I'm so glad Math was my strongest subject.

    One more thing is the super turbine 400 (Switch pitch) the same tranny as the th400 with more desirable options. Do they have the same bellhousing? I ask because I found one for 150.
    I'm leaning toward the th400 if a manual transmission doesn't fall in to local add for cheap but I'm not betting on it.
    I just want to get the Buick running on its own power.
    Still kind of up in the air because I can get this 700r4 for 35$ off some guy who doesn't know what he has.
     

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  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    The ST400 was Buick's name for the THM 400. Of course, the 65-67 ST 400 was a switch pitch. The 65 and 66 switch pitch would have a Nailhead bell housing. The 67 would be the BOP bell housing.
     
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  10. Donuts & Peelouts

    Donuts & Peelouts Life's 2 Short. Live like it.

    Dang it was 65-66.
     
  11. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    There might be an adapter plate you can use.
     
  12. wkillgs

    wkillgs Gold Level Contributor

    There was a ST400 in 1966 with the BOP bellhousing. It was used behind the 340 small block on the LeSabre 400.
    401-425 Nailhead bellhousing is easy to ID, has a round shape.
     
  13. Donuts & Peelouts

    Donuts & Peelouts Life's 2 Short. Live like it.

    Larry when looking for a 4l80e can I consider a 4x4 version.
     
  14. Donuts & Peelouts

    Donuts & Peelouts Life's 2 Short. Live like it.

    I looked up gear vendors they are cool but to expensive, any body do what they do but cheaper
     
  15. Donuts & Peelouts

    Donuts & Peelouts Life's 2 Short. Live like it.

    I seen this guy in YouTube running a 4l80e with no computer
     
  16. TexasT

    TexasT Texas, where are you from

    4l80e is a good trans. 4x4 one will require a tail housing , the 4x4 just has the splined shaft hanging out where it goes into the transfer case.
    those guys without a computer have a manual valve body . Works good but you have to shift it. I want my auto trans to be automatic. And it still needs an adapter plate to bolt it up to the Buick engine.
     
  17. Donuts & Peelouts

    Donuts & Peelouts Life's 2 Short. Live like it.

    Thanks Texas T. So does the manual valve body give you the ability to take the engines rpms higher and the ability to downshift from let's say 3rds to 2nd to give it some go.. so the 4x4 will work.

    As far as a computer route will I need the computer from the same vehicle or can a non 4x4 comp run the 4x4 4l80e?
     
  18. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Try looking for a used GV. They are nearly indestructible so you should be able to find a good one. Cheaper, no matter what route you go, it will end up costing you the same if you do it right. Used GV might be the cheapest way to go.
     
  19. Donuts & Peelouts

    Donuts & Peelouts Life's 2 Short. Live like it.

  20. TexasT

    TexasT Texas, where are you from

    http://www.phoenixtrans.com/wp-content/uploads/2014/07/compushift101.pdf

    this is an article on the compushift that phoenix trans recommends. I trust these guys and have done business with them for about 25 yrs. They do converters too. They did the lockup I use in the 2004r I run in my turbo regal.
    a manual vb is just that. It effectively turns the 4l80e into a manual trans with a torque converter instead of a clutch. You control when it shifts be it up or down.

    the 4x4 trans will work but you will need to source a tail housing to have it work in a non4x4 application. When hunting look for vans. Even the v6 had a 4l80e in some of the heavy duty vans . Just have to look underneath to see if it has one.
     
    Last edited: Aug 30, 2017
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