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Reverse or drive clunk

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by fireinthehole, Sep 6, 2003.

    I searched the posts but didnt get the answer I was looking for. Whe I put my Sub into gear, either reverse or drive there is a loud clunk. It doesnt sound normal. Is this usually caused from worn u-joints?

    This is on a 3/4 Sub with th400, 14b sf 4wd

    Mat
     
  1. sled_dog

    sled_dog 1 ton status

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    I had it caused by insanely bad u joints, and spider gears. I replaced my u joint and it got better but still noticed it, welded my spiders in the 10 bolt now its not there anymore.
     
  2. MTBLAZER89

    MTBLAZER89 3/4 ton status GMOTM Winner

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    Wait till ya get a Detroit.... /forums/images/graemlins/grin.gif Ya just get used to it.
     
  3. mudhog

    mudhog THEGAME Staff Member Super Moderator

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    yes it sounds like ujoints. to test it put blocks behind the wheels put it in neutral and then twist the drivline by hand back and forth and you should be able to tell if it the front or back ujoint on the driveline
     
  4. sdavid

    sdavid 1/2 ton status

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    Worn transmission/t-case mount will do it too. If you can get under your Burb and move your trans around pretty easily with your hands or a small pry bar, it is probably worn.
     
  5. Jonny-K5

    Jonny-K5 1/2 ton status

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    i have the same clunk, new ujoints. when i had it aligned the guys there said it was too much backlash in the ring and pinion. probly the same thing.
     
  6. Jonny-K5

    Jonny-K5 1/2 ton status

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    i have the same clunk, new ujoints. when i had it aligned the guys there said it was too much backlash in the ring and pinion. probly the same thing.have a buddy hold the brakes and go from D to R a few times while your looking at the rear shaft. you should see the shaft move back and forth a considerable amount if its in the diff.
     
  7. Hustler

    Hustler 1/2 ton status

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    I would say you have one of three problems. Maybe a combination of the three. Either Trans mount worn, U-Joint, or ring & Pinion.
     
  8. Batmanjr

    Batmanjr 1/2 ton status

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    There are many laces inside your pumpkin which can wear and allow for slack... There is no way an alignment guy can tell you it's all backlash unless he actually took your cover off and held the ring gear in place! In order for the ring gear to be held still the spiders must be tight and the splines on the axle shafts as well.... I agree with the detriot comment...! Mine has about a half turn of play! You do get used to it! If you get under there and it turns out to be all in your diff, and you still have a 10 bolt.... Don't bother with fixing it, just replace it with a 14FF and upgrade! If it's already a 14FF, you can do them yourself and tell the gear guy that you want to keep the $500 labor charge! /forums/images/graemlins/thumb.gif
     
  9. Jonny-K5

    Jonny-K5 1/2 ton status

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    he wasnt "just " an alignment guy, more of a driveline guy, and he just said thats what it probly was. i know it is coming from the axle. i have a trutrac, ya think it could be from that? dont mean to hijack.
     

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