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4.0 Harmonic Balancer - know when it's going bad & how to fix

Discussion in 'Stock 2002 - 2005 Explorers' started by Cobra Jet, December 29, 2010.

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    1. Cobra Jet

      Cobra Jet Member

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      MODS, please "sticky" this thread...

      I have searched this site and have included the pertinent 4.0 harmonic balancer threads into this one, to make it easier for future reference and to help those who are seeking the proper information regarding the 4.0 balancer issues.


      This is a very problematic issue w/ the 4.0 Explorers (as well as the 4.0 Sport Tracs).

      The first signs of a 4.0 balancer starting to fail - distinct "chirping or squealing" of which resembles a serpentine belt squeal. At idle, the noise will resemble a "chirp", however, when driving, the noise will progressively get louder as RPM's increase and will turn into a loud pitched squealing, slowing down again when coming to a stop. The noise will be coming directly from the balancer if positioned under the vehicle while listening at idle. IF the serpentine belt is removed, the balancer will not squeal or chirp, it will only do it w/ the belt on and under tension. If all other front end accessory pulleys do not make ANY noises when manually spun (w/ engine & belt OFF), the harmonic balancer is the problem.

      Besides the obvious chirping/squealing, other ways to detect a failing 4.0 harmonic balancer:

      1) watch the serpentine belt & belt tensioner @ idle - if the belt is not following a smooth path while running and the belt tensioner is sporadically "jumping or bobbing", it's a bad balancer

      2) if while watching the serpentine belt @ idle and looking down at the balancer, if you see ANY slight wobbling of the balancer, any run-out or that it's not tracking straight, it's a bad balancer

      3) with the serpentine belt off, if you tug on the front of the balancer pulley and the OUTER ribbed pulley moves even slightly, can be wobbled back and forth (side to side) or in some instances will pull/slide forward (towards radiator) or can be pushed backwards (towards engine), it's a bad balancer

      4) if the bonded rubber elastomeric center that secures the outer ribbed crank pulley to the center of the balancer is either protruding (not flush w/ the face of the metal pulley) OR there are visible signs of dry rotting/cracking/deterioration, it's a bad balancer

      5) IF the serpentine belt is NOT on the RIBBED section of the crank/balancer pulley and is in FRONT of it on what appears to be a smooth rubber surface, then the balancer has already separated and you should not be driving the vehicle.

      Too many of us have had to replace this part - luckily some of us did not have extensive repair bills, while unfortunately other failures have resulted in more damages & extensive repair bills.

      There is a revised 4.0 balancer (crank pulley) through Ford that is better and not like the original design.
      The revised 4.0 harmonic balancer Ford part # is: 8L2Z-6B321-A


      IF you take your vehicle to a Ford Dealer (or other shops) - do NOT let them tell you it's just a bad belt or other misc. pulley causing the chirp or squeal, especially after you have confirmed via steps 1-5 above that the source of your problem IS the balancer. You do not want to continue to drive a vehicle w/ a bad harmonic balancer as you will and can only cause more damages to other surrounding components or even worse, end up with possible engine damages - fix a bad balancer ASAP.

      PICS & DISCUSSION OF FAILED BALANCER: http://www.explorerforum.com/forums/showthread.php?t=296853

      MORE PICS & DISCUSSION OF FAILED BALANCER: http://www.explorerforum.com/forums/showthread.php?t=267709

      HOW TO R&R THE BALANCER: http://www.explorerforum.com/forums/showpost.php?p=2509603&postcount=4

      MISC. BALANCER DISCUSSION: http://www.explorerforum.com/forums/showthread.php?t=299522&highlight=harmonic+balancer

      MISC. BALANCER DISCUSSION: http://www.explorerforum.com/forums/showthread.php?p=2589015#post2589015

      ~~~~

      If others have more to add to this thread, feel free to do so. It's important that other/all 4.0 Explorer and Sport Trac owners are aware of this common problem.
       
      Last edited: December 30, 2010
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    3. swetrid

      swetrid Well-Known Member

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      04-05 years have a weight/ring inside the pulley that becomes loose, you can feel it loose when you reach inside in the pulley itself and cant be seen.
       
    4. RKelly2233

      RKelly2233 Active Member

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      thanks cobra... ill be getting that done next week to get rid of that damn chirp.
       
    5. scott_holland

      scott_holland New Member

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      just wanted to know I have a loud knocking sound on my 2004 explorer so we thought it may have droped a valve so we took the valve covers off but it all looked ok...one of the valves wasnt closed so he went to turn the motor by hand and when he put his finger inside of the balancer i heard the knocking sound.We think that is the same sound.So I just wanted to know if this is possably my problem and if it has happen to anyone else....
       
    6. pyrofallout

      pyrofallout New Member

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      Thank you for putting all this info together! Just wanted to chime in here. My 04 Ford Ranger 4.0L started chirping/squealing early last week. Was able to look at it on Saturday and found that the outer section of my harmonic balancer had separated from the rubber ring and slid back against the engine. The belt caught on the rubber and started wearing into it. At first I figured it to be tensioners going bad but I am glad I got this looked at soon enough and was lucky, from other horror stories I am seeing, the damage could have been pretty bad. $350 for a new balancer and labor to do the swap and all is well again.
       
    7. Sparky94

      Sparky94 Active Member

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      my explorer is making a fart/grind type noise coming from that area of the engine and the belt bobs, could that be it? this is on the ohv 4.0.
       
    8. jgdski

      jgdski New Member

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      So, the dealer where I bought my car new in 05 changed my belt about 1 year ago... About 1-2 weeks ago my belt started squeaking... It was worse when I pressed on the gas and went away at idle... I didn't read anything on the web at the time so I brought it back to the dealers shop and they said the belt had to be replaced. I had the belt replaced, and 110000 mile service, for $240. I drove to and from work two days and last night when I started the car the battery light came on, followed by the "service charging station" warning light. I soon discovered my power steering was gone too... I looked under the hood and discovered I had no belt. I had the car towed this morning to the dealers shop and I expected them to replace the belt and give me something for my troubles... To my surprise they called and said the harmonic balancer was the problem and they would give me free labor to install new one for $330. I told them it seems strange I never had a belt problem before and 2 days after they change the belt there is suddenly this problem...??? Does this make sense to anyone? Any comments? (I doubt anyone will see this before tomorrow morning but if you do, and you know something about this, your input is appreciated.)
       
    9. matt0248

      matt0248 Active Member

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      your balancer was the problem all along, they will cause a squeaking noise that sounds just like a slipping belt, but it is the dampener from the section where the belt rides. sepearating.
       
    10. Exproblems

      Exproblems Well-Known Member

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      >>>>>>>>>>>

      Either the mechanic is a scum bag and tampered with your vehicle trying to cause you other mechanical problems causing your new belt to break off, thus getting more repair $$$$$ work out of you, , or he is a complete idiot and installed the new belt wrong and never tested it by starting the engine to see how it is tracking on the pulleys. He may not have seated the new belt on the Harmonic Balancer pulley correctly and it snapped when you drove it later because it was off it's track. This may explain why he is offering you free labor to change the Harmonic Balancer, because he screwed up the first time and he's trying to cover his a$$. If I were you, take the vehicle to a different mechanic and don't tell them what the other guy charged you. Get a new quote and see if your Harmonic Balancer is really bad. This mechanic you went to sounds awful shady to me and his prices are outrageous.
      FYI, I just checked out a price for an OE Harmonic Balancer from Advance Auto Parts, they want $160.00 for it and you can get $40 off that price ordering it online using an online coupon for their store. You could possibly find one cheaper online at some other parts outlet. So as far as your mechanic telling you he is going to do the labor for free on the Harmonic Balancer job, he is full of $hit! That price he gave you of $330 includes his labor charge. The guy is a crook.
       
      Last edited: October 6, 2011
    11. jgdski

      jgdski New Member

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      Thank you VERY much for your time and your response. Yesterday the dealership service manager manager called and he told me the sensor and balancer needed to be replaced. He said the parts were $250 and he said he would charge me $125... After the sticker shock of $330 the previous day it seemed like I was getting quite a deal... I accepted the $125 offer but I will take your advice and stop bringing my car to the dealership for service... THANKS!!!
       
    12. Exproblems

      Exproblems Well-Known Member

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      >>>>>>>>>>>
      >>>>>>>>>

      The service manager at this dealership is now offering you a lower price ($125 for parts and labor) for the Harmonic Balancer repair that he previously quoted you at $330? Sounds like he is "guilty" of something. Is this a Ford dealership or a smaller, privately owned dealership/car lot? I'd still stay away from this guy and take it to some other repair shop, because he way over charged you for the first serpentine belt installation ($240 is ridiculous for a belt install) and since you never had a problem with the Harmonic Balancer prior to taking your vehicle to him, he is the one who probably damaged your Harmonic Balancer to begin with after he installed the serpentine belt on wrong, causing damage to it. I wouldn't let this guy get within 2 feet of my vehicle.
       
    13. Fighting5thSVT

      Fighting5thSVT New Member

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      Well, I too have succumbed to the notorious failure that is this balancer. This is ridiculous. I have no idea how long the pulley has been like this or how it even ran at all. I am just glad I found it before it totally let loose while driving....

      [​IMG][/IMG]
      [​IMG][/IMG]
      [​IMG][/IMG]
      [​IMG][/IMG]

      Grooves for the belt are nearly 100% smoothed:mad:
       
    14. capnrandy

      capnrandy New Member

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      Removing the balancer crankshaft pulley

      2002 Explorer with 4.0L ~105kmiles. Chirping noise, or belt squeek that is driving me crazy. Replaced all the idler pulley and tensioner pulley… replaced the alternator. Noise goes away when I run the truck without a belt. After some research… I think it must be the crank pulley/harmonic balancer – even though it looks fine? I’m going to go ahead and replace it. Can anyone tell me if I can pull the balancer/pulley without removing the fan and radiator? Looks pretty tight to get the thing pulled out? Thanks for the help.
       
    15. swetrid

      swetrid Well-Known Member

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      On 2002 year we have had some problems with water pump pulley wearing and causing noise. You could try pulley and new belt.
       
    16. capnrandy

      capnrandy New Member

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      water pump

      when i had the belt off i turned the waterpump and it seemed smooth? You think it might be the water pump? or just the pulley? it looks fine, and the belt is new. maybe i didnt look at the pulley that close. i'll pull the belt back off and take a look. if that is the issue would it be obvious when looking at it?
       
    17. capnrandy

      capnrandy New Member

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      crankshaft pulley

      I looked at the water pump pulley, and it really looks fine. I dont think that is the issue. Fan clutch looks fine. I see some cracking or dry rot on the rubber between the harmonic balancer and the crankshaft pulley - so still think that is the issue. Anyone know if it can be pulled off without removing the fan and the radiator?
       
    18. Artbaileyjr

      Artbaileyjr New Member

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      I'm going to replace the balancer on my '02 4.0L in the near future. I have read through several threads related to the balancer. It all looks pretty straight forward; Not unlike any other Ford product. What I seem to recall is a post somewhere, where a special tool is used to start the balancer onto the crank to pull it on far enough to pick up enough threads to bottom it out with the bolt.

      Is it possible to work the balancer on by hand, far enough to use the (new) bolt or will I be doing some tool creation using the original (apparently, non-reusable, torque to yield) bolt along with some cutting and welding?

      Anybody have any tricks (or advice) that they would like to share, so I can have my ducks in a row before I start?

      Much appreciated.
      Art
       
    19. scdix50

      scdix50 Elite Explorer

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      There is about an 1/8 inch difference on the length of snoult and where the bolt engages the threads of crankshaft. When you are pulling the old balancer you will run out of threads on bolt. I used a light hammer to finish sliding the old balancer off. When I was installing my new balancer I just kept tapping and checking to see if I could start the old bolt back into the crank threads. REMEMBER!!!! you can not let the crankshaft to rotate backward. I used crankshaft locking tool from my cam timing tool set to lock balancer while loosening the balancer bolt.. I used a chain wrench to hold balancer when torqueing the bolt.
       
    20. Artbaileyjr

      Artbaileyjr New Member

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      I will heed your advice. I usually use a balancer holding tool of my own design (it uses the puller bolt holes) when removing/installing the bolt. I'll make sure that it is locked in a stationary position during installation.

      So.... to sumarize.... It's really no different than doing a garden variety 5.0L (for example), other than you can not allow the crank to rotate backward.

      I ordinarily dress the end of the crank, and an inch or so of the bore of the balancer with fine sandpaper and a light coat of oil to allow it to start onto the crank without undue pounding with a BFH. Sounds like the same routine.

      I appreciate the input. Sounds like a piece of cake. :D
      Regards,
      Art
       
    21. treats54

      treats54 New Member

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      I have replaced the alternator, idler pulley and tensioner pulley in an effort to stop the ridiculous chirp i am hearing on my '04 X. I have checked the crank pulley for any wobble or looseness by hand and nothing moves. When I pulled the belt off, it had a slight stickiness to the crank pulley (I had sprayed belt dressing on it a few weeks prior). The chirp is only there in colder weather and when using the fan for heat or A/C when stopped. The crank pulley does show some signs of wear. Could it be that I just need to replace the pulley?
       
    22. bmagsanay

      bmagsanay New Member

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      Water Pump Pulley "Play"?

      My serpentine belt "let go" while driving my 2001 Sport Trac 4.0L. I replaced the belt and tensioner pulley assembly, but chirp and another sound (clacking?) remain. I noticed the belt will not stay in the grooves of the crank pulley. The harmonic balancer/pulley assembly looks ok and I don't detect any play or looseness in the pulley.

      However, the water pump/fan pulley DOES have play when I move a fan blade back and forth, between engine and radiator. Should this pulley have play like that?
      Thanks for any feedback.
       
    23. trump

      trump New Member

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      I have a whining noise or a humming noise on my 05 4.0 only on acceleration that I can't hear at idle. Coulld the balancer be causing the whine or the hum?
       
      Last edited: April 29, 2012
    24. RickOTR

      RickOTR Active Member

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      This is all very interesting. I've had a faint rattling sound under my truck for a while now that I cannot solve. It sounds like a baby rattle by the balancer, but I cannot be 100% sure that's what it is. Could it be the 4x4 balance shaft chain riding against that tensioner...
       
    25. Teejay4490

      Teejay4490 Active Member

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      Sooooo... I just had my harmonic balancer, the bolt and basically the whole assembly replaced...

      ITS STILL CHIRPING!!

      Is the new one bad or what? My previous one chirped for 2 years lol.
       
    26. jstorm001

      jstorm001 Member

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      I used belt dressing on my belt beginning of the year it was the worst thing I ever used It made my belt chirp & squeal and caused Slippage on the pulleys I had to replace the belt and clean all that crap off the pulleys still chirped but within a month or two stopped .It claimed it helped the belt last longer & helped pulleys with less wear and tear only reason I used it ! Worst mistake ever!!!
       

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