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  1. #1
    LTXTech Sponsor


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    Gail C. Cahall
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    Default Some information about 5 pinion planetaries

    I get asked quite often why we don't use 5 pinion 4L65E planetaries. Actually there are a few reasons that I will try to explain. The largest percentage of the time that a planetary fails is because the needle bearing set under the sun gear fails first. When that bearing fails, it sheds needles through the pinions, causing it to self destruct. Both 4 and 5 pinion planets use the same style bearing. I've never seen a 4 pinion planetary fail in a way that a 5 pinion wouldn't have failed the same way. Now, we add in the other factor. 5 pinion planetaries are much heavier than 4 pinions. This is rotationg weight. The more weight you have to spin, the more horsepower it takes to turn something. It may not be dramatic, but a few extra horsepower is a few extra horsepower. The other thing in cost. A REAL GM 5 pinion rear planetary costs upwards of $400. Many shops will advertise "5 pinion planetaries". The first question should always be, "Are they REAL GM planetaries". There are companies making cheap knock offs that I've seen fail is as little as 300 miles. I've seen the pinion exles fall out, and the housings themselves shatter.
    So, in a nutshell, a 5 pinion offers little, if any strength improvement, they cost a couple horsepower, they're heavier, and unless they're REAL GM planetaries, they're actually weaker. CPT does however offer 5 pinion REAL GM planetaries as an option if the customer is dead set on them.

    Frank
    Gail C. Cahall
    CAHALL PERFORMANCE TRANSMISSIONS

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  3. #2
    LTX Shootout Coordinator


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    Frank i am really liking the advice you are giving keep it up
    A4, BOLT ONS, TIMMY BUILT TRANS, 4000 STALL S60 410 GEARS,STREET STOCK ALL THE WAY ,AUTO MOITION TUNE, FULL INTEIRIOR, AC,A REAL DAILY DRIVER 12.58 1.65 60FT 108.78 MPH @ 2500FT DA

  4. #3
    Long Live the Opti


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    Sean
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    Default

    Good info as always Frank!

  5. #4
    The Wrench


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    Chile
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    Made this a stickie. Very good info Frank. A good way to eduacate our fellow members.
    ASE L1 Master Certified Tech's 9C1 T56. Yeah she's got a big butt. But watch her move it.

    R.I.P. Z8

  6. #5
    InActive Member


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    Default

    Quote Originally Posted by Cahall View Post
    I get asked quite often why we don't use 5 pinion 4L65E planetaries. Actually there are a few reasons that I will try to explain. The largest percentage of the time that a planetary fails is because the needle bearing set under the sun gear fails first. When that bearing fails, it sheds needles through the pinions, causing it to self destruct. Both 4 and 5 pinion planets use the same style bearing. I've never seen a 4 pinion planetary fail in a way that a 5 pinion wouldn't have failed the same way. Now, we add in the other factor. 5 pinion planetaries are much heavier than 4 pinions. This is rotationg weight. The more weight you have to spin, the more horsepower it takes to turn something. It may not be dramatic, but a few extra horsepower is a few extra horsepower. The other thing in cost. A REAL GM 5 pinion rear planetary costs upwards of $400. Many shops will advertise "5 pinion planetaries". The first question should always be, "Are they REAL GM planetaries". There are companies making cheap knock offs that I've seen fail is as little as 300 miles. I've seen the pinion exles fall out, and the housings themselves shatter.
    So, in a nutshell, a 5 pinion offers little, if any strength improvement, they cost a couple horsepower, they're heavier, and unless they're REAL GM planetaries, they're actually weaker. CPT does however offer 5 pinion REAL GM planetaries as an option if the customer is dead set on them.

    Frank
    thank you for this info, I hate hype, you keep this up (being so dang honest) I might let you build my trans LOL.

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