Can I run the car up to speed with the drive shaft off?

Discussion in '94-95 5.0 - Specific' started by CrystalWhite, Jun 16, 2015.

  1. CrystalWhite

    CrystalWhite New Member

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    Hey all. I am trying to find a driveline vibration and I just replaced my U-joints and found the front one to be going bad, but that didn't solve my problem (vibration actually got worse). It is a lot of work/expensive (7 hour drive 1 way) to get my drive shaft balanced if I need it done. For this reason I was wondering if I can run the car with it off to make sure the vibration isn't in the clutch assembly?
     
  2. lutter94

    lutter94 Well-Known Member

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    Can't you run it up in neutral to do the same thing? It would be virtually identical to what you're proposing....I don't think it would make a difference..
     
  3. CrystalWhite

    CrystalWhite New Member

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    Yeah you're right (I have been having a bit of a rough day haha). I also wasn't sure if there would be any difference if something was messed up with the output portion of the trans maybe.
     
  4. lutter94

    lutter94 Well-Known Member

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    I think it's possible you could lose fluid out the tail shaft. I would just put it back in and run it up in neutral...
     
  5. CrystalWhite

    CrystalWhite New Member

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    I just threw it back in and this time I rotated it 180 just to see if it made a difference. While not moving revving with the clutch pedal in or in neutral feels exactly the same and there is no vibration. The vibration is there while moving under load or just coasting.

    I am really confused why the vibration got worse when I installed new U-joints. They were moving freely with no binding or rough spots. I also made sure everything went back in the same direction as when I took it apart.
     
  6. lutter94

    lutter94 Well-Known Member

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    u joints are usually noticeably worse under load. Is it exactly the same no matter the load?
     
  7. CrystalWhite

    CrystalWhite New Member

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    Before I changed the U-joints, the vibration was at certain speed intervals and it didn't seem to make any noticeable difference if it was under load or not. The vibration would get really bad at above normal highway speed and just keep getting worse (I don't normally drive fast, but the couple times I did, I noticed it and it's violent) I am talking 90-100 mph. If it was up to that speed and I let off the throttle then the vibration becomes very violent.

    Since I have changed the U-joints, it vibrates more than it did previously and at lower speeds and more violent and the load does not seem to make a difference. I don't even want to drive it on the highway now because it feels like I am going to do some damage since it is vibrating so much. I know it has to be something with the drive shaft since it is the only thing I touched.
     
  8. lutter94

    lutter94 Well-Known Member

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    Sure its not a wheel bearing?
     
  9. CrystalWhite

    CrystalWhite New Member

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    Yeah they're good. There was no noise or play when I checked.
     
  10. lutter94

    lutter94 Well-Known Member

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    Can you run it on Jack stands in gear
     
  11. CrystalWhite

    CrystalWhite New Member

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    I am not comfortable running it up to highway speed on stands. I did do it running in first gear to check for bent axles and everything looks fine.
     
  12. Cpotts13

    Cpotts13 Well-Known Member

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    Are your wheela balanced..... Seriously.. Haha.

    Also, it would be a hell of a lot cheaper to buy a used driveshaft off of eBay. That's what I did when I had drive line vibrations. $30 shipped.
     
  13. lutter94

    lutter94 Well-Known Member

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    Could just be an unbalanced driveshaft.
     
  14. ElrodKTPQ_89

    ElrodKTPQ_89 Legend

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    Am I the only one thinking maybe it could be the balancer?
     
  15. CrystalWhite

    CrystalWhite New Member

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    I just pulled the DS back out again to double check the u-joint installation and everything seems fine. The slip yoke does have a small gouge in it big enough to catch my fingernail. Checked it with a straight edge and calipers and it doesn't appear bent or excessively worn. The car only has 40k miles on it, would you think it is too soon to suspect the tailshaft bushing? I don't see any play in the tailshaft at all.

    Since there is nowhere to get my DS balanced locally because I live in the sticks, I think I am going to pick up an aluminum DS from FRPP.
     
  16. CrystalWhite

    CrystalWhite New Member

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    That's always in the back of my mind, but I replaced it last year and I don't have the vibration unless I am moving.
     
  17. ReplicaR

    ReplicaR Well-Known Member

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    I've been fighting driveshaft vibration for years, especially after the torque arm installation, since that made it more obvious that it's there. I got the FRPP Aluminum driveshaft in the car now, and it's a pretty big difference on how much smoother it is over stock driveshaft, even if it was balanced. I also found out that driveshaft position on the rear end makes a difference. There are 4 ways you can bolt it back up, since there are 4 holes. Try unbolting the driveshaft, rotating it 90 degrees and bolting it up again. That's how I was able to reduce my vibration when I still had the factory driveshaft.
     
  18. hotmustang95

    hotmustang95 Active Member

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    Same here only with no TA. Drove me crazy for years. A new FRPP aluminum DS solved it. One of the best mods money can buy and its cheap.
     
  19. CrystalWhite

    CrystalWhite New Member

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    Got it ordered! Anyone have any clearance issues with the alum DS? I have heard some people saying it hits the ebrake bracket or something.
     
  20. ReplicaR

    ReplicaR Well-Known Member

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    I had it rubbing a little bit, but I ground away some of the bracket. Seems fine now.