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Hot Rods Chasing T5 Vibration

Discussion in 'The Hokey Ass Message Board' started by wstory, Oct 5, 2018.

  1. Great news. Merry Christmas to you as well.
     
  2. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,910

    dirty old man
    Member Emeritus

    Must have been that gearset you had replaced, I agree. And that's got to make your Christmas a little merrier now that it's resolved. So yes, MERRY CHRISTMAS!!!!!!!!!!
     
  3. wstory
    Joined: Jul 4, 2008
    Posts: 1,715

    wstory
    Member
    from So Calif

    Welllll,....I'm back! Vibration is back orrrrr,....maybe because I improved so many parameters, I thought I'd fixed it. WRONG! It's been 8 months and 4K miles since the last post and I have destroyed everything from the crank flange back. driveshaft.jpg IMG_1392.JPG IMG_1393.JPG IMG_1401.JPG IMG_1402.JPG IMG_1403.JPG
    The U-joint skipped outta the pinion yoke (probably my fault after so many in & outs). The driveshaft whipping about levered off the driveshaft loop and tore the rear mount loose. The resulting violence broke the trans case.
    What I noticed each time the T5 was out was, the input shaft seemed a little sloppy (side to side). The builder said, not unusual and not a problem. Reference that note.
    I now have a new remanufactured (by a name shop) trans. The input shaft seems much more precise. A new pinion yoke, trans mount and T/O bearing are on the bench. A new driveshaft will be built when everything is back together.
    HOWEVERrrrrr! In the process of checking anything that may have been the source of the vibe, I discovered that the pressure plate was out of balance by one ounce!....a lot, I'd say! The pressure plate has been in the car for over 120K miles with no perceptible vibration. But here's what's relevant I believe.
    My take is, the original trans (before T5) being a heavier truck unit dampened the imbalance to the point it was not perceptible. The replacement T5, being a lighter duty unit (and with a sloppy input shaft) allowed the imbalance vibration to be "experienced".
    So, I'm pretty confident I've discovered the source of the vibration first experience about a year and 10K miles ago. The pisser is,...I had to destroy the whole drivetrain to find it.:eek:
     
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  4. big duece
    Joined: Jul 28, 2008
    Posts: 6,830

    big duece
    Member
    from kansas

    That looks like a NWC unit. The World Class units have a bearing support on the countershaft for 5th gear, but its stamped steel. The couple units I rebuilt I installed the billet countershaft support, and only get it from 5speeds.com all the others are of lesser quality. Only the WC units are drilled for this kit, NWC are not.
    https://www.5speeds.com/t5.htm
    Is it possible that gear box was thrashed hard before you using it?
     
  5. big duece
    Joined: Jul 28, 2008
    Posts: 6,830

    big duece
    Member
    from kansas

    Input shaft when proper preload set up still can have a wee bit of side to side movement. There should be NO end movement on input shaft. There is a shim pack under the input shaft bearing, and .001 to .002 preload on the front bearing works well.
     
  6. wstory
    Joined: Jul 4, 2008
    Posts: 1,715

    wstory
    Member
    from So Calif

     
  7. big duece
    Joined: Jul 28, 2008
    Posts: 6,830

    big duece
    Member
    from kansas

    I seen the cracked case, ouch. I wondered in its previous life, had it been driven hard the countershaft bearing bore can get distorted.
     
  8. enjenjo
    Joined: Mar 2, 2001
    Posts: 2,689

    enjenjo
    Member
    from swanton oh

    I think you should replace the rear end yoke too, they very often bend when you lose a driveshaft like that.
     
    dirty old man likes this.
  9. krylon32
    Joined: Jan 29, 2006
    Posts: 9,397

    krylon32
    ALLIANCE MEMBER
    from Nebraska
    1. Central Nebraska H.A.M.B.

    We're also chasing the same vibration on my deuce 3 window. That's what we were doing last fall when the shop working on the car forgot to push the safety latch and the drivers door flew open at 80+ MPH. Finally got the car repaired this summer and started all over again. Replaced the driveshaft with a new balanced one, balanced the tires, checked the rear axles for run out checked the center section, and finally took it to a suspension wizard with a dino and he thought he had it figured with pinion angle. So far the vibration continues? I've built 100's of chassis with the same motor, trans and rear end angle with no vibration problems. The vibration comes in when you shift it to 5th gear at about 55 and goes away just over 60. You can feel no vibration coming thru the shift lever. The tires are 10 years old so I'm replacing those. I grasping for straws at this point.
     
  10. wstory
    Joined: Jul 4, 2008
    Posts: 1,715

    wstory
    Member
    from So Calif

    Silly me!!!!!!!
    For those who have not given up on this tragedy, "It's always something!", right. I think I was lucky early on,.... before I installed the T5. Before the T5, there were a number of things that were not right, but the combo worked. As I started messing with the setup, many of those things that previously worked , did not in the new setup. I have done everything as documented in previous post(s). Each yielded some improvement but did not yield the vibration free ride I felt should be attainable.
    A week ago Thursday, I raised the engine/trans 3/4", flattening the drive shaft angel more and, ....viola!!!! 90% of the vibe gone. On perfectly smooth pavement and a constant 65-70 mph, I can still experience a very light vibration,....if I really focus. Very acceptable, if necessary. However, not being inclined to leave well enough alone, I am just now heading for the garage to adjust the pinion angle a bit,....seeking perfection (in an old rattle trap Ford) :eek:
     
    VANDENPLAS likes this.
  11. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,910

    dirty old man
    Member Emeritus

    THX for reporting this progress, Bill. Please come back again and tell us your findings, changes, and results on the pinion angle efforts up coming.
     
  12. Sounds like your heading in the right direction.
     
  13. wstory
    Joined: Jul 4, 2008
    Posts: 1,715

    wstory
    Member
    from So Calif

    I know I've said it before. Hope it's the last time on this subject. "I got it!"
    More tuning of the pinion angle got me where I wanted to be. Driveshaft shop said, "forget the by the book angles". They usta do that but often still had vibrations. Rotate the drive shaft so's the knuckles are vertical and stick your finger in the open space top and bottom. Allow a diff. of about 1/8" between the top and bottom,....(or the bottom and top depending whether you are at the trans or pinion end). Doesn't have to be perfect. I love my car again.
     
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  14. krylon32
    Joined: Jan 29, 2006
    Posts: 9,397

    krylon32
    ALLIANCE MEMBER
    from Nebraska
    1. Central Nebraska H.A.M.B.

    Good for you. I talked to the shop working on my 3 window and after all the changes and adjustments we still have the vibration that comes in at about 40 in 4th and really gets going when you shift into 5th over 50. We've checked the driveshaft, differential, axles, wheels, tires, changed the pinion angle. There's a vibration but it doesn't transfer up thru the shifter. Maybe it'll end being yard art?
     
  15. beater32
    Joined: Mar 23, 2008
    Posts: 368

    beater32
    Member

    I have pretty much the same issue. Fine when cruising but when I bury my foot around 50 to change up I get a vibration also. I have Poly mounts all round so was thinking of swapping out the trans one from rubber to start with.?

    Sent from my ZTE R84 using The H.A.M.B. mobile app
     
  16. wstory
    Joined: Jul 4, 2008
    Posts: 1,715

    wstory
    Member
    from So Calif

    krylon32, I did not see that you messed with the engine/trans angle. You know that the angle, trans to driveshaft and the angle driveshaft to pinion should be the same or very close,...right? Does the vibration only occur when under load,....like accelerating???? decelerating???? what about free wheeling????
    beater32, I changed my urethane trans mount to rubber (recommended by driveshaft shop) as a component of my journey several steps back. Don't know if that was a factor but I'm not putting the urethane back in just to see.
     
  17. krylon32
    Joined: Jan 29, 2006
    Posts: 9,397

    krylon32
    ALLIANCE MEMBER
    from Nebraska
    1. Central Nebraska H.A.M.B.

    I've built 100's of customer chassis with the same mounts and angles with manual and automatic trans with housing centered 9 inch rears and never had a complaint. I do have urethane mounts on both the motor and trans but they've never been a problem before. Sometimes I wonder if the motor might have something to do with it but it should vibrate in all the gears at a certain rpm if it was the motor?
     

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