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Hot Rods Overdrive transmission clunk?

Discussion in 'The Hokey Ass Message Board' started by Boden, Apr 28, 2020.

  1. Boden
    Joined: Oct 10, 2018
    Posts: 747

    Boden

    So I have installed my overdrive manual trans in my 53. I have not driven it yet due to a a few starter parts on back order. Anyways I was pushing the car out of the garage today and I was hearing a clunk. It is in neutral. The od is not hooked up yet. I am just going to run it as a 3 speed for now. But anyways I’m hearing a clunk. And I’m really worried there’s something wrong with the trans. So I jack it up and spin the driveshaft by hand and I can hear it’s coming from the tail-shaft. This is really freaking me out. What can this be?


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  2. FrozenMerc
    Joined: Sep 4, 2009
    Posts: 3,103

    FrozenMerc
    Member

    Couple of options to consider:

    Drive shaft yoke bottoming out in housing due to too long of driveshaft (assuming open driveline)
    Drive shaft yoke bearing in tail shaft worn and allowing the yoke to wobble
    Excessive back lash in the OD planetary gear set
    Bad U-Joint
    Incorrect Yoke / Tailsahft spline fitment

    Does the clunk occur once per revolution of the driveshaft, or just when the car is rocked back and forth?
     
  3. Boden
    Joined: Oct 10, 2018
    Posts: 747

    Boden

    It occurs every inch or so of rotation. And I don’t think the driveshaft is bottoming because I have had it pushed all the way in and it is not very close to all the way in when there is weight on the rear. And it is open driveline. And the other thing I was thinking it might be the overdrive cable position. The only thing is. I’m not sure which way is free wheeling. And which way is engaged



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  4. squirrel
    Joined: Sep 23, 2004
    Posts: 56,085

    squirrel
    Member

    pushed in is "on", pulled out is "off. So if the cable is pushed in, it will freewheel (until the overdrive solenoid kicks in)
     
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  5. nunattax
    Joined: Jan 10, 2011
    Posts: 3,066

    nunattax
    Member
    from IRELAND

    does not sound good for the trans are you in R or D.are u in gear . what model gearbox
     
    Last edited: Apr 28, 2020
  6. Boden
    Joined: Oct 10, 2018
    Posts: 747

    Boden

    I am in neutral. An now. When I turned the shaft that the cable bolts to since I don’t have a cable hooked up it will not let the car roll backwards. But I did notice the sound only happens when the car rolls bsckwards


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  7. jaracer
    Joined: Oct 4, 2008
    Posts: 2,446

    jaracer
    Member

    Sounds to me that you need to pull the trans and see what is wrong. Just locking out the overdrive, which is what I assume you mean by your last post, shouldn't have any effect on the car rolling backwards in neutral. All the lever does is lock up the OD planetary unit so you have direct drive. It sounds like maybe your 1st/rev sliding gear isn't actually in the neutral position.
     
  8. Boden
    Joined: Oct 10, 2018
    Posts: 747

    Boden

    Ooooooo. I do have an aftermarket shifter installed. I wonder if it’s not returning to neutral all the way


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  9. Boden
    Joined: Oct 10, 2018
    Posts: 747

    Boden

    Nope. I unhooked the shifter and the trans seemed all the way in neutral. But now the od cable shaft seems sloppy and as if it’s not connected to anything in the trans


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  10. Automotive Stud
    Joined: Sep 26, 2004
    Posts: 4,311

    Automotive Stud
    Member

    Push the overdrive lockout lever forward, towards the front of the car. That should lock out the overdrive and you shouldn't hear any noise. If it's back it's in the overdrive position, even in neutral you will hear the overdrive freewheel. That's why in overdrive you have to park these cars in reverse, so they don't roll backward. I don't think there's anything wrong with your transmission.
     
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  11. Boden
    Joined: Oct 10, 2018
    Posts: 747

    Boden

    I tried that. And at first it didn’t work. That’s why I made this post. But the. I figured to try it again. And this time it worked. I guess that I didn’t fully disengage it ewrlier


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  12. plym_46
    Joined: Sep 8, 2005
    Posts: 4,018

    plym_46
    Member
    from central NY

    You are not supposed to try to reverse with the lock lever in. This is the default position. Reversing can do something to the sun gear bearing and it the ramped paths they run in. Till it's sorted out the lock out in its forward position and wire it or zip tie it to hold that position. Supposedly they are equiped with a reverse over ride that does this as reverse is solected. Mine doesn't work right so I always pull the cable out when I park the car in case I forget and need reverse to leave the garage or a parking space. There is a down loaded BW r10 0perators
    manual in downloads section of the p15-d24 website. I think you can open and read it as a guest. You need to be a member to print it from the forum. The od's were pretty much across the brands so they all work in a similar fashion. I believe 5th avenue garage has stuff on their site also.
    Here too

    https://www.enginebuildermag.com/20...QcYl3m85sVyYC2HThnJa0NI5Eih2uQZIwxhpeWNNHI0hM
     
    Last edited: Apr 30, 2020
  13. jaracer
    Joined: Oct 4, 2008
    Posts: 2,446

    jaracer
    Member

    So you have to pull the cable out in order to backup? I had two cars with OD transmissions, backed them up with the cable pushed in (OD engaged) many times. Because I was 16-17, I had the transmissions out of both cars multiple times, but it was always broken gears in the main transmission and being a lead foot.
     
  14. Automotive Stud
    Joined: Sep 26, 2004
    Posts: 4,311

    Automotive Stud
    Member

    It's a good habit to get into, but like plym said, there should be a rod inside of the transmission that takes care of it. These were in production cars, they tried to make them stupid proof. That said, stuffs old and worn and may not function like it was designed anymore.
     
  15. Mike51Merc
    Joined: Dec 5, 2008
    Posts: 3,855

    Mike51Merc
    Member

    Some handy terms for the four normal states of overdrive:
    Overdrive Enabled= system ready/able to operate; trans freewheels when coasting until OD Engaged by speed over 23 +/- mph.
    Overdrive Disabled= system unable to operate, trans locked in direct drive, no freewheeling.
    Overdrive Engaged= OD upshifted to .7 overdrive; controlled by governor switch feeding solenoid, no freewheeling.
    Overdrive Disengaged. Trans in direct drive.

    The cable pull lever Enables and Disables overdrive.
    The solenoid (together with other electric components) Engages and Disengages overdrive.

    You can drive in reverse with OD enabled, but not engaged.
    The car will freewheel with OD enabled, but not engaged.
    The car will not freewheel with OD disabled.

    With OD Enabled, car will freewheel backwards (with engine off) in forward gears, so use parking brake!
     
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  16. Boden
    Joined: Oct 10, 2018
    Posts: 747

    Boden

    Perfect. Thank you very much. These terms will help alot


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