What are the symptoms of a U-Joint going bad?

Discussion in '80-Series Tech' started by HuletCruiser, Apr 13, 2007.

  1. HuletCruiser

    HuletCruiser

    Joined:
    Jul 21, 2006
    Messages:
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    Location:
    Traverse City, Michigan
    Hello folks,

    Im still brainstroming a condition with my curiser.

    While coasting on smooth pavement, there is a "gearing" feeling in the drivetrain. It also is most noticable when gently braking to a stop. You don't feel it on any accelleration though.

    I put the cruiser in "N" and blocked the wheels freeing the drive alxes and neither the front or rear seem to have any noticable "play." Not sure if this would be a way to tell of a U-joint is going bad.

    Fluid in the diffs and transfer case were all changed last summer. This new condition is about 2 months old. Mind you, its not a horrible condition, I just feel something is a rye. I still drive it daily with out any fear of a brake down.

    Thanks for any experiences that you have had that may explain what might be going on with my cruiser!

    Jason Hulet
    Traverse City, MI
     
  2. C6H12O6

    C6H12O6

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    Location:
    Beaverton, Oregon
    I'm sure people will sound off here, but I think most people have either a vibration at various speeds, a clunking noise when shifting from R to D, or a metal-on-metal screeching noise at low speeds.

    A "gearing" noise might be some mis-alignment in a ring and pinion. It seems that with normal maintenance, Tcase problems are relatively rare. Have you checked the diff fluid? Gone through any water since your last fluid change? I would start there. You may have blown a seal somewhere in the front end and have some fluid issues since the change. Not unheard of. When was the last front axle service done?

    Checked the condition of your diff & tcase breathers? I know some people have had issues where a plugged up breather has led to some funky stuff in the diffs.
     
  3. jonheld

    jonheld

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    Simplest dignostic is to remove 1 driveshaft at a time, lock the center diff and go for a test ride. That will isolate the noise to driveshaft vs anything else and tell you which one is at fault.

    While the driveshafts are out, manually work each uni through it's range of motion on each axis. You're looking for a "notch" in the movement. If you find a notch then you can rebuild that uni or a not so gentle whack with a hammer on the bearing caps and a good shot of grease may make all your dreams come true.

    You also want to check for rotational play in the slip yolk of each shaft. Too much play can lead to a "buzz" when there is no load on the driveline such as when coasting.
     
  4. beno

    beno 33030-60450 Moderator Supporting Vendor

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    If the sound is coming when you are decelerating with your foot off of the skinny pedal, and you are getting a "rumble strip" type sound, then there is a good chance your front or rear output bearings in your transfer case are "going."

    You could easily drive for thousands of miles in this type of situation (ask me how I know....:rolleyes: ).

    I'd do what Jon recommended--take each shaft out and run around a bit at high-way speeds and slower speeds and see if you hear the sound with one shaft out and one shaft in.

    Regardless, if you have a bunch of miles on your cruiser, I would recommend a nice PM of rebuilt drive shafts--new OEM joints and balanced at a reputable driveline shop.

    If you are still getting the noise, then transfer case would be my next area of concern. Unfortunately, if it is your front output bearing, plan on dropping your xfer case to get to the front extension housing.

    Good luck.
    -onur
     
  5. HuletCruiser

    HuletCruiser

    Joined:
    Jul 21, 2006
    Messages:
    19
    Location:
    Traverse City, Michigan
    Thank you, for your answers...

    Thank you for all the replies.

    I noticed today a slight "ticking" when at low speeds coasting. It seemed to either go away at higher speeds or I just couldn't hear it. I do have a "rumble" when coming to a stop coasting and also when applying brakes normaly. I did a total rebuild of the front end last fall - birfield knuckles. I also checked the diff fluid in the front diff and changed the fluid in the transfer case, which was also done last summer. My drive shafts seem solid. Rumble & low speed "tick" seem to be coming from the front end.

    Vehicle has Lockers and has 140,000 miles on it. Year 1997. TLC.

    Also, it doesn't seem any better or worse when the wheel is turned either direction vs straight. Drives fine and the rumble is more of a feel then a noise. The "tick" is a noise though.

    Was wishing for a nice shot U-joint but this sounds more involved.

    I had comments saying to remove the front axle and drive around to see if the noise was gone. Im not sure how this is done. I did take the drive shafts out of each side during the birfield rebuild but how do I drive the TLC without the front axle! :eek:

    Thanks all, if all else fail, I'll have to take it in... I have a bad feeling about this one....:eek:

    Jason
    Traverse City, MI
    1997 TLC, Locked, Black
     
  6. HuletCruiser

    HuletCruiser

    Joined:
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    Location:
    Traverse City, Michigan
    ok, understood...

    Ok, while re-reading the posts, I see... remove one of the drive shafts NOT axles! Sorry... I got ya. Thanks!

    Jason:rolleyes:
     

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