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Thread: Changing the crankshaft pulley - looking for guidance

  1. #21
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    If you are doing this just to keep it from rubbing on the fan belt why can't you just use a flat file or even a dremel tool to grind down
    the dented in portion?

  2. #22
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    Quote Originally Posted by cdrusn View Post
    If you are doing this just to keep it from rubbing on the fan belt why can't you just use a flat file or even a dremel tool to grind down
    the dented in portion?
    I might have to try and go out to the garage and take some different pictures to show you. It's a challenge to photograph well because of the lighting and also because it depends on where the engine rotation happens to stop. The portion that's pushed in slightly is only on the alternator belt part of the pulley. And it's maybe less than an inch long, so what, like 30 degrees perhaps total out of the 360 degrees that make up the entire circumference.

    It's not really something that you'd grind down as it isn't a burr or little nub. It's that when one side of that V groove is pushed in slightly, the belt does not sit down in that groove anymore for that small section. As the pulley rotates round and round, much of the time that little 30 degree section isn't touching the belt. But every revolution, it tends to bump the belt out a little bit because it won't sit down in the groove nice and flat like it does on the rest of the pulley portions. So it wobbles. And since there is also some rougher parts of that surface now because it's been like that for so long, it has knicked the belt a couple times and started a fray. And I also think the wobble is adding extra wear on the bearings inside the alternator.

    Here's a pic I had from last season.

    IMG_2136.jpg

    Notice just to the right of where the belt is covering you can see the top edge of the pulley groove pushed in towards the centre. It's dark and hard to see, like I said, it's difficult to photograph. I think it could be fixed with David's suggestion of reshaping it using a small piece of rod that would fit in the groove and let you bang that edge back out a little at a time until you got it where you want it.

    What I might do is take the alternator belt off and perhaps the muffler and bracket and better photograph and assess what I have to work with. I'll post those pictures here when I do.


    Sept. 81, auto, black interior

  3. #23
    Senior Member DMC-81's Avatar
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    Quote Originally Posted by Jonathan View Post
    I might have to try and go out to the garage and take some different pictures to show you. It's a challenge to photograph well because of the lighting and also because it depends on where the engine rotation happens to stop. The portion that's pushed in slightly is only on the alternator belt part of the pulley. And it's maybe less than an inch long, so what, like 30 degrees perhaps total out of the 360 degrees that make up the entire circumference.

    It's not really something that you'd grind down as it isn't a burr or little nub. It's that when one side of that V groove is pushed in slightly, the belt does not sit down in that groove anymore for that small section. As the pulley rotates round and round, much of the time that little 30 degree section isn't touching the belt. But every revolution, it tends to bump the belt out a little bit because it won't sit down in the groove nice and flat like it does on the rest of the pulley portions. So it wobbles. And since there is also some rougher parts of that surface now because it's been like that for so long, it has knicked the belt a couple times and started a fray. And I also think the wobble is adding extra wear on the bearings inside the alternator.

    Here's a pic I had from last season.

    IMG_2136.jpg

    Notice just to the right of where the belt is covering you can see the top edge of the pulley groove pushed in towards the centre. It's dark and hard to see, like I said, it's difficult to photograph. I think it could be fixed with David's suggestion of reshaping it using a small piece of rod that would fit in the groove and let you bang that edge back out a little at a time until you got it where you want it.

    What I might do is take the alternator belt off and perhaps the muffler and bracket and better photograph and assess what I have to work with. I'll post those pictures here when I do.
    Jonathan,

    To expand on David's T's suggestion, can you try to bend out the pushed in section with a vise? You can protect the pulley with one paint stirrer or soft flat metal stock on each side of the vise jaws. You may have to devise a jig set-up because of the small V area. If so, you would want to start with the normal area to get a feel for what the appropriate angle is, and rotate the pulley in your jig towards the damaged area and beyond. Gently tighten the vise each time (e.g. like tighten, release, rotate an inch, and then repeat). Always look at your work in the process mid-stream to ensure you are on the right track and not bending too much. Just be patient. I prefer this method versus hitting the part with a hammer which does an uneven job and adds hammer marks (in my experience).

    I had to do a similar operation on an NLA drive axle flange component that was previously wallowed out by letting the axles hang. On this part, I used circular supports/protectors (PVC pipe) that were a similar diameter as the part. It turned out just as good as new.

    Here are pics:
    Damaged:


    Repaired:
    Dana

    1981 DeLorean DMC-12 (5 Speed, Gas Flap, Black Interior, Windshield Antenna, Dark Gray)
    Restored as "mostly correct, but with flaws corrected". Pictures and comments of my restoration are in the albums section on my profile.
    1985 Chevrolet Corvette, Z51, 4+3 manual
    2006 Dodge Magnum R/T (D/D)
    2010 Camaro SS (Transformers Edition)

  4. #24
    Administrator Ron's Avatar
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    Something else you might try-
    Cover an undamaged portion of the groove with Saran Wrap and pack it with Sonic Weld to get the right shape, leaving an ample amount protruding to strike with a small hammer...

  5. #25
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    We can circle back and try some of the dent repair ideas afterwards as I went ahead and bought a new replacement pulley. And a new nut, and seal, and belt, and alternator. Been a while since I bought anything for the car so this is good. Should be here in a couple of days.

    I think I have a good handle on getting the nut loosened, but what I want to hear from one of you is what tools or procedures are needed for getting the nut back to the torque it needs to be? I have the torque wrench, that's the easy part. I wasn't sure what needs to be done to "lock" the engine in place while you tighten it? I have an automatic transmission on a stock engine with pretty much everything else on the car stock too.


    Sept. 81, auto, black interior

  6. #26
    Senior Member DMC-81's Avatar
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    Quote Originally Posted by Jonathan View Post
    We can circle back and try some of the dent repair ideas afterwards as I went ahead and bought a new replacement pulley. And a new nut, and seal, and belt, and alternator. Been a while since I bought anything for the car so this is good. Should be here in a couple of days.

    I think I have a good handle on getting the nut loosened, but what I want to hear from one of you is what tools or procedures are needed for getting the nut back to the torque it needs to be? I have the torque wrench, that's the easy part. I wasn't sure what needs to be done to "lock" the engine in place while you tighten it? I have an automatic transmission on a stock engine with pretty much everything else on the car stock too.
    Excellent. A new pulley is even better. I'll defer to others whether putting the transmission in Park is enough/advisable.
    Dana

    1981 DeLorean DMC-12 (5 Speed, Gas Flap, Black Interior, Windshield Antenna, Dark Gray)
    Restored as "mostly correct, but with flaws corrected". Pictures and comments of my restoration are in the albums section on my profile.
    1985 Chevrolet Corvette, Z51, 4+3 manual
    2006 Dodge Magnum R/T (D/D)
    2010 Camaro SS (Transformers Edition)

  7. #27
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    My VIN:    03238 Grey & Black Hybrid - Auto - work in progress Former owner 10902 - Universal 93 Raffle Car

    Quote Originally Posted by Jonathan View Post
    Thankfully there's been no leaking from there on my car. It drips on the other end of the engine, between the engine and trans, but not at that crankshaft pulley.
    Before you resign yourself to repairing the main seal in the future - take a long close look at that leak at the other end of the engine - I thought I had a leaking main seal, but it was higher up leaking past the main seal, thankfully.

    Get the car up on ramps and get way back under there and clean everything down there back to as clean as possible - get all the grime and oil off and pristine if you can. if you have a few suspect areas you can try overlapping a thin strap of paper towel with painter tape below watch suspect area to catch leaks immediate at the source. Run the engine briefly, and check, and for progressively longer and hotter until the leak reveals itself. The camshaft closing plates, valve cover gaskets, and blanking plates on the head may leak and look like a rear main seal. Soooooo much easier to fix!


    Fingers crossed for you.

    Tom

  8. #28
    Administrator Ron's Avatar
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    Quote Originally Posted by DMC-81 View Post
    Excellent. A new pulley is even better. I'll defer to others whether putting the transmission in Park is enough/advisable.
    +1


    ...Park will not help hold it at all -- Jamb up the torque converter/flexplate through the bell housing/starter hole.

  9. #29
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    Quote Originally Posted by Ron View Post
    +1


    ...Park will not help hold it at all -- Jamb up the torque converter/flexplate through the bell housing/starter hole.
    Ok.... any details on how to accomplish this? Assuming not using Spaceballs jam?


    Sept. 81, auto, black interior

  10. #30
    Administrator Ron's Avatar
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    lol.
    I'd disconnect the battery, jack up the rear -- place jack stands, remove the starter. Get a very large screwdriver and place it in the flexplate. Make sure you get a good bite so that you don't damage the teeth etc. Tighten until the engine turns and binds aqainst the the screwdriver. Add Loctite to threads. Double check that you have a good bite and tighten to 135 ft.lb. (183 Nm)

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