Harmonic balancer failure | Ford Explorer - Ford Ranger Forums - Serious Explorations

  • Register Today It's free! This box and some ads will disappear once registered!

Harmonic balancer failure

2000StreetRod

Staff member
Moderator
Elite Explorer
Joined
May 26, 2009
Messages
10,598
Reaction score
269
City, State
Greenville, SC
Year, Model & Trim Level
00 Sport FI, 03 Ltd V8
Recently some Sport Trac members have reported experiencing harmonic balancer failures that have resulted in repairs ranging from minor to moderate repair costs. In one case the repair was limited to replacement of the failed balancer and reinstallation of the serpentine belt. In another case the balancer, crankshaft position sensor and serpentine belt had to be replaced in addition to a towing bill due to being stranded on the highway.

The harmonic balancer failure has not been limited to Sport Tracs. It has also occurred on 1st generation Explorers.

I have not read anything in Ford's documentation about the expected life of the harmonic balancer nor the warning signs of its impending failure. I suspect that the serpentine belt slipping off track may be an indicator.

I think it would be helpful to members if those who have experienced a harmonic balancer failure would share their experience with emphasis on the age and mileage of the engine and any warning symptoms realized in retrospect. Did you notice that the belt tensioner was moving in and out due to the balancer rotating off center? Was there a sound coming from the area of the balancer due to it rubbing against the crankshaft position sensor? Please post any photos you may have of a failed or damaged balancer.

Thank you in advance for sharing!
 


Join the Elite Explorers for $20 per year. Gets rid of the ads! New $5 per month "try out" option.

Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private conversations, and more. Join Today. Your support is greatly appreciated.




2000StreetRod

Staff member
Moderator
Elite Explorer
Joined
May 26, 2009
Messages
10,598
Reaction score
269
City, State
Greenville, SC
Year, Model & Trim Level
00 Sport FI, 03 Ltd V8
One type of failure

Below is a photo I found in a thread after doing a search. It shows the balancer inner and outer parts have separated and the outer part has slipped toward the rear. Apparently the serpentine belt had come off and the owner had reinstalled the belt to run on the inner section of the balancer not noticing the grooved section had slipped to the rear.
HarmBalancer.jpg

As soon as it quits raining I'm going to see if my inner and outer sections are still aligned. Below is a photo Aldive posted in the thread showing his still good stock balancer before it was replaced with an underdrive damper.
GoodDamper.jpg
 




Joined
September 2, 2009
Messages
45
Reaction score
0
City, State
london
Year, Model & Trim Level
97 4.0 SOHC 99 4.0 SOHC
you may be able to inspect for play in the rubber by using a spanner on the bottom. I have seen a few where the rubber had perished and cracked and possibly may have led to this sort of failure if left on the vehicle.
 




cdvorcek

New Member
Joined
December 10, 2008
Messages
2
Reaction score
0
Year, Model & Trim Level
2001 Sport Trac
Below is a photo I found in a thread after doing a search. It shows the balancer inner and outer parts have separated and the outer part has slipped toward the rear. Apparently the serpentine belt had come off and the owner had reinstalled the belt to run on the inner section of the balancer not noticing the grooved section had slipped to the rear.
View attachment 57891
As soon as it quits raining I'm going to see if my inner and outer sections are still aligned. Below is a photo Aldive posted in the thread showing his still good stock balancer before it was replaced with an underdrive damper.
View attachment 57892
 




cdvorcek

New Member
Joined
December 10, 2008
Messages
2
Reaction score
0
Year, Model & Trim Level
2001 Sport Trac
I have a 2005 Sport Trac that experienced a harmonic balancer failure. Your pictures are right on target. The first thing that happened is the balancer burnt a hole through the Air Conditioner manifold hose. I believe this to be a design flaw. The AC manifold hose should never have been installed in such close proximity to the crankshaft pulley. Secondly, the crankshaft pulley slid back farenough to eat the crankshaft sensor. Cost for a new crankshaft pulley/harmonic balancer, new crankshaft sensor, new AC manifold hose, new serpentine belt, evac and re-charge of the AC system was $980.00. The only saving grace is that it did not totally separate. That could have possibly taken the rediator and AC condensor as well.
 




stang354

New Member
Joined
August 3, 2010
Messages
4
Reaction score
0
City, State
Massapequa, NY
Year, Model & Trim Level
2004 XLT 4.0
I know its an old thread but my balancer looks just like the one above! It look like the belt is suppose to be riding on the rubber because perfect ribs are worn on it! Thanks for this thread! New balancer is on the way.

Only symptom was a belt squeak that just started yesterday. God only knows how long this has been like this. I noticed that one of the ribs on the original belt had seperated from the rest of the belt in a 12 inch section. This led to more inspection and noticing tiny pieces of rubber stuck to the frame and surrounding hoses. Now that I see the picture of the main pulley walking off of the rubber I see that its not suppose to look that way lol! My 04 XLT 4.0 has 82K on it.
 








stang354

New Member
Joined
August 3, 2010
Messages
4
Reaction score
0
City, State
Massapequa, NY
Year, Model & Trim Level
2004 XLT 4.0
The balancer retaining bolt is a torque-to-yield bolt on the SOHC V6 and should not be used. I don't know about the other engines.

Hmm..anyone have a part number of the bolt?
 




stang354

New Member
Joined
August 3, 2010
Messages
4
Reaction score
0
City, State
Massapequa, NY
Year, Model & Trim Level
2004 XLT 4.0
Got the bolt..now before I go at it, is it revrese thread or standard?
 








ranger7ltr

Elite Explorer
Joined
November 17, 2001
Messages
1,308
Reaction score
18
City, State
Great State of Texas
Year, Model & Trim Level
1999 Sport
TTY balancer bolts...

The balancer retaining bolt is a torque-to-yield bolt on the SOHC V6 and should not be used. I don't know about the other engines.

To clarify the harmonic balancer bolt on ALL Ford 4.0 liter v6 engines is torque-to-yield and should be replaced when removed...

The 5.0 lter V8 Ford engine does not use a torque to yield bolt for the harmonic balancer...
 




ibjammin

New Member
Joined
August 18, 2010
Messages
1
Reaction score
0
City, State
Hartselle, AL
Year, Model & Trim Level
2010 Sport Trac
Harmonic Balancer on 2010

I bought a New Sport Trac in March 2010, and immediately started having problems.

400 mi had the front right rotor turned.
500 mi had the drive shaft replaced. (vibrations)
550 mi had the front right tire replaced (vibrations)
Last week at 5,300 mi had the harmonic balancer replaced...started making a squealing sound upon starting.

Scouring the WEB I see that there is quite a large problem with the harmonic balancer. Ford seems not to want to admit that there is a problem, but I have the local Maintenance manager admitting on hidden camera that it is a known (large) problem, and that the new part may have the same problem as the old part!

Thinking of trying to start a class action suit against Ford.
I am a disabled Vet with three life threatening illnesses and I need a dependable vehicle to transport me to, and from the VA hospital numerous times per year...I did not get dependable from Ford.

ibjammin
 




nhmercracer

New Member
Joined
October 19, 2008
Messages
8
Reaction score
1
City, State
Boston. MA
Year, Model & Trim Level
2005
Copied from another thread to document.

The balancer in my 2005 failed the other day. It started with the usual squeak. I, like many others here, replaced the belt, and the squeak went away for a short time. The chirping returned, but louder. The noise seemed to be rpm related, so I assumed the alternator bearings had failed. I observed the tensioner bouncing, as others have. I removed the new belt, and turned the alternator by hand. It seemed to squeak when turned in one direction. I should have observed the noise was present when turning the pulley in the wrong (counter-clockwise) direction. I researched the parts, and was prepared to R and R the alternator. While on a short errand to procure some parts, I started the Ex, and upon turning the steering wheel, got a charging system error, which promptly went away.

I had my g/f turn the wheel, with the lights and A/C on. The entire belt system would completely stop for 1/2 second immediately as the wheel was turned.

When we returned home, I removed the belt again. Every pulley seemed OK. However, when I attempted to thread the belt back around the bottom of the crank pulley, the outer ring, where the belt rides, turned without turning the engine!

I have the failed balancer/pulley.

Called Dorman. I was told the 4.0 pulley P/N: 594-111 which they have listed, will not work on the later SOHC.

Finally called the local dealer. There is a new style pulley from Ford. P/N: 8L2Z-6B321-A retails for $198.91.

I picked it up, and ordered a replacement bolt. I removed the defective balancer using the process others have perfected here on ExplorerForums.

This work included the starter bump/breaker bar method for bolt removal. I disconnected the coil pack wiring connector, as well as removed the crank position sensor, to prevent starting, and damage to the sensor. I covered the radiator to protect it as well. Works excellent!!

I'll get it finished when the new bolt arrives on Monday.

Pictures for now:



New part on the right. There is a huge change, the outer hub is now fully vulcanized to the inner hub.



The exciter ring is totally different.



Another view.



Close up of the failed bonded joint.



I'll update when I am finished.

Sean
 




nhmercracer

New Member
Joined
October 19, 2008
Messages
8
Reaction score
1
City, State
Boston. MA
Year, Model & Trim Level
2005
2000's reply to my post.

Sean, thank you for posting the information and photos. Apparently Ford has recognized that there is a reliability issue with the 3rd generation SOHC V6 balancers. I started a thread some time ago in an attempt to document the deficiency: Harmonic balancer failure

I'm curious about the first photo (front view) you posted of the new balancer. There appears to be an non-symmetrical, unfinished metallic piece on the left side of the inner section. It appears rather crude compared to the rest of the assembly.

I checked the part number on the Ford database and it shows the balancer as a replacement for all of the SOHC V6 engines from 1997 thru 2010 and the Sport Trac from 2007 thru 2020.
 




nhmercracer

New Member
Joined
October 19, 2008
Messages
8
Reaction score
1
City, State
Boston. MA
Year, Model & Trim Level
2005
A better picture of the replacement.

I think it is just my picture making it look like that. Here is a better view.




The worst thing is I get charged full retail at the Ford dealer. :(
 




ahodges

Elite Explorer
Joined
August 31, 2009
Messages
1,364
Reaction score
53
City, State
Millbury, OH
Year, Model & Trim Level
1996 XLT - 347 S/C
I have a 96 4.0 OHV and also had to replace the harmonic balancer. My truck had 122,000 miles on it at this point. My symptoms were that the tensioner was oscillating as if one of the pulleys had a wobble to it.. I inspected the balancer and the rubber was dry rotted. I went to the dealer to order a new one and the replacement was the balancer you see above.

When you use the new design balancer, the crank shaft position sensor also has to be replaced due to the redesigned exciter ring.

Once I replaced it the tensioner pulley stopped oscillating.

I believe that the harmonic balancer is the same for all of the 4.0 explorer engines since they all use the same block and stroke..

By the way.. Don't pay the $198.00 for that balancer.. If nothing else you can get it through a vendor on here for only 10% above cost and that comes out to somewhere around $120..
 




nhmercracer

New Member
Joined
October 19, 2008
Messages
8
Reaction score
1
City, State
Boston. MA
Year, Model & Trim Level
2005
I could not wait as I needed the vehicle running asap. I reused the original CPS with no issues. The truck has been running daily for almost a week.
 




ahodges

Elite Explorer
Joined
August 31, 2009
Messages
1,364
Reaction score
53
City, State
Millbury, OH
Year, Model & Trim Level
1996 XLT - 347 S/C
I could not wait as I needed the vehicle running asap. I reused the original CPS with no issues. The truck has been running daily for almost a week.

Hmmm.. well then the dealer's computer lies when they say you need a new and improved CPS.. oh well..
 




nhmercracer

New Member
Joined
October 19, 2008
Messages
8
Reaction score
1
City, State
Boston. MA
Year, Model & Trim Level
2005
My Ex is a 2005, perhaps it is a different (or newer) unit than the one originally installed on your Ex?
 


Join the Elite Explorers for $20 per year. Gets rid of the ads! New $5 per month "try out" option.

Elite Explorer members see no advertisements, no banner ads, no double underlined links, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create and save more private conversations, and more. Join Today. Your support is greatly appreciated.




ahodges

Elite Explorer
Joined
August 31, 2009
Messages
1,364
Reaction score
53
City, State
Millbury, OH
Year, Model & Trim Level
1996 XLT - 347 S/C
My Ex is a 2005, perhaps it is a different (or newer) unit than the one originally installed on your Ex?

That is very possible seeing how there is a 9 year difference.. Im not too concerned about it. I still have the old one as a back up maybe, ya never know! lol
 




Top