Harmonic Balancer

bronco9588 · **Joined:** Sat Oct 29, 2011 8:17 pm **Posts:** 69

I am hearing a pretty bad rattle like a loose bolt, but the serpentine belt looks great and the tensioner is not moving.

Pretty sure I need a new harmonic balancer. The problem is that the part is discontinued. Anybody know where to source one? Preferably new.

WWDiesel · **Posted:** Mon May 18, 2020 4:02 pm

bronco9588 wrote:

I am hearing a pretty bad rattle like a loose bolt, but the serpentine belt looks great and the tensioner is not moving.
Pretty sure I need a new harmonic balancer. The problem is that the part is discontinued. Anybody know where to source one? Preferably new.

Keep in mind, a worn out engine mount on these vehicles can rattle like a bucket of loose bolts at idle. Been there done that!

A few sites like Summit and a few of the Mopar sites still list new balancers but I would call for availability before ordering just to be sure. :google:

or try one of these, they rebuild harmonic balancers. I believe a few on LOST have reported using them to rebuild their dampers.

http://damperdoctor.com/index.php?route=common/home

another one:
Harmonic Balancer Rebuilding/ Repair at Dale Manufacturing:> https://www.damperdoctor.com/

bronco9588 · **Joined:** Sat Oct 29, 2011 8:17 pm **Posts:** 69

Is there a good test to figure out if it is the motor mounts? Probably not a bad idea to replace. 215K on the vehicle. Motor mounts are probably original but definitely have 145k miles on them

bronco9588 · **Joined:** Sat Oct 29, 2011 8:17 pm **Posts:** 69

Thanks for the link to damper doctor!

I tried summit, but unable to find anything on their website that is compatible.

Car has 215K and probably has original damper and motor mounts. They have at least 150K on them. Any way to test the motor mounts vs the harmonic damper?

turblediesel · **Posted:** Mon May 18, 2020 8:45 pm

Take them off and shake them. They'll look fine but rattle. I changed mine at 70,000 miles. The one on the right rattled and the left one didn't.

WWDiesel · **Posted:** Mon May 18, 2020 10:06 pm

bronco9588 wrote:

Thanks for the link to damper doctor!
I tried summit, but unable to find anything on their website that is compatible.
Car has 215K and probably has original damper and motor mounts. They have at least 150K on them. Any way to test the motor mounts vs the harmonic damper?

Summit:> Mopar Replacement Crankshaft Pulley 5072669AA
I would certainly call them to confirm availability and fitment.
https://www.summitracing.com/parts/mop- ... ner=SREPD2

Quote:

Any way to test the motor mounts vs the harmonic damper?

Remove engine mount and shake, if it sounds like a coffee can full of loose bolts, it is bad. They are notorious for going bad with age...

or while engine is idling:
locate the rattle using a Mechanic's Automotive stethoscope. :wink:

bronco9588 · **Joined:** Sat Oct 29, 2011 8:17 pm **Posts:** 69

Well... my school of thougut is to start with replacing the mounts. We will see if this is the fix. I drive too many miles to not take care of the vehicle. Maybe she will purr a little nicer for me.

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

bronco9588 wrote:

Well... my school of thougut is to start with replacing the mounts. We will see if this is the fix. I drive too many miles to not take care of the vehicle. Maybe she will purr a little nicer for me.

At 215,000 miles with engine mounts of unknown age, I'd recommend replacing them (as well as the transmission mount while you're under there). Did mine at around 130,000 and all sorts of noises, rattles, and vibrations I seemingly couldn't track down went away.

bronco9588 · **Joined:** Sat Oct 29, 2011 8:17 pm **Posts:** 69

casm wrote:

bronco9588 wrote:

Well... my school of thougut is to start with replacing the mounts. We will see if this is the fix. I drive too many miles to not take care of the vehicle. Maybe she will purr a little nicer for me.

At 215,000 miles with engine mounts of unknown age, I'd recommend replacing them (as well as the transmission mount while you're under there). Did mine at around 130,000 and all sorts of noises, rattles, and vibrations I seemingly couldn't track down went away.

I bought the car with 73K. And yes, I purchased the tranny mount. Hopefully this wont take all of my memorial day weekend.

WWDiesel · **Posted:** Tue May 19, 2020 2:39 pm

casm wrote:

bronco9588 wrote:

Well... my school of thought is to start with replacing the mounts. We will see if this is the fix. I drive too many miles to not take care of the vehicle. Maybe she will purr a little nicer for me.

At 215,000 miles with engine mounts of unknown age, I'd recommend replacing them (as well as the transmission mount while you're under there). Did mine at around 130,000 and all sorts of noises, rattles, and vibrations I seemingly couldn't track down went away.

X2
Same for me, @ 138k I chased a rattling noise at idle for several weeks. Kept thinking it was belt related; replaced serpentine belt tensioner, alternator pulley, serpentine belt, and finely replaced all three mounts, engine & transmission. Noise was gone.
After removing left motor mount, you could shake it by hand and it sounded like a metal coffee can full of loose nuts & bolts. :shock:

bronco9588 · **Joined:** Sat Oct 29, 2011 8:17 pm **Posts:** 69

So I put in a couple hours on the jeep today. Some good news and some bad news.

1) The motor mounts have been swapped and the old ones shake like maracas. They definately needed to be replaced. The passenger side was fairly easy, but the driver side is a pain with the differential.

2) I ran the engine and the loose bolt sound is still present. I decided to pull the serpentine belt to rule out the tensioner, decoupler, air conditioner, power steering, and viscous heater. Sadly the sound was still present. At this point, I am thinking I have isolated the rattle to the vibration damper, or something internal.

3) I will be be sending the damper out for a rebuild.

4) I was thinking of pulling off the timing belt cover and checking tensions and torques since I am pretty much there.

5) Can I run the enginer for a couple minutes at idle with the damper off? I want to isolate the problem to the damper instead of chase around a bunch of problems. I don't know if this will tell me anything. I just don't know how "broken" the damper will look.

6) Anybody leave the fan shroud out? Its a pain to take in and out.

bronco9588 · **Joined:** Sat Oct 29, 2011 8:17 pm **Posts:** 69

So I pulled the balancer and the rubber was missing chunks and had a half dozen cracks. Pretty sure it was the source of the noise. I still plan to take a look at the timing belt while I am at it.

But thanks for pushing for new motor mounts. I might need to replace the car, but the motor mounts are good.

bronco9588 · **Joined:** Sat Oct 29, 2011 8:17 pm **Posts:** 69

So I pulled the balancer and the rubber was missing chunks and had a half dozen cracks. Pretty sure it was the source of the noise. I still plan to take a look at the timing belt while I am at it.

But thanks for pushing for new motor mounts. I might need to replace the car, but the motor mounts are good.

TKB4 · **Posted:** Sun May 24, 2020 1:43 pm

You can leave the shroud off but I would do the fan shroud mod and put it back on . Its easy to do basically just cut shroud just above the upper bolts (or you can do below the upper bolts if you want) You dont have to make a bracket to hold the top piece down if you dont want to. Before you remove fan etc the first time you can even do this in place with a vibratory cutter in less than 10 minutes. The you just leave lower portion of shroud in until fan out and 4 bolts to remove it if you want. It might tend to overheat if you tow anything without the shroud.

geordi · **Posted:** Sun May 24, 2020 7:18 pm

It will NOT overheat without the shroud - the shroud is too far away from the fan to be any kind of a duct, the fan moves a ton of air by itself anyway. Toss the bottom half of the shroud and don't look back.

If you want more cooling, think about the GM 11 blade fan and the Hayden clutch, but otherwise you are good to go. The top of the shroud is a safety cover to keep fingers out of the fan, nothing more.

TKB4 · **Posted:** Tue May 26, 2020 9:09 am

Agree, but I am one who uses one of mine with the fan removed, so I chose to leave it because the top is a good place to attach ac hoses etc to keep them from rubbing things and for me the bottom half doesn't get in the way. I only made a piece to hold the 2 halves together the first time since then just cut in place then put back in when finished TB job etc. I am also one (probably like Geordi ) that does Timing Belt job without removing the front cap. It goes a lot faster that way and just doesn't really add difficulty. Can do Timing belt job by itself in 5-6 hours with power or air ratchet the range is basically how long it takes to make sure timing pins are right and allowing to reposition belt a couple of times when getting CP3 timed with cams etc.

Congrats on tackling this problem yourself and working it through to completion. I am just now making time to replace an engine even though I have had it 6 months!!

bronco9588 · **Joined:** Sat Oct 29, 2011 8:17 pm **Posts:** 69

TKB4 wrote:

Agree, but I am one who uses one of mine with the fan removed, so I chose to leave it because the top is a good place to attach ac hoses etc to keep them from rubbing things and for me the bottom half doesn't get in the way. I only made a piece to hold the 2 halves together the first time since then just cut in place then put back in when finished TB job etc. I am also one (probably like Geordi ) that does Timing Belt job without removing the front cap. It goes a lot faster that way and just doesn't really add difficulty. Can do Timing belt job by itself in 5-6 hours with power or air ratchet the range is basically how long it takes to make sure timing pins are right and allowing to reposition belt a couple of times when getting CP3 timed with cams etc.

I removed most of the front of the car the first time I did the timing belt replacement. The second time took me about 6 hours and I didn't remove the inter cooler. Should I pull the timing cover while I am this far in? I'm 99% sure it is the balancer. BUT if it was a loose bolt inside the timing belt, I am sure that the engine would be toast by now.

TKB4 wrote:

Congrats on tackling this problem yourself and working it through to completion. I am just now making time to replace an engine even though I have had it 6 months!!

The life-cycle of this car is every 6 months something expensive breaks. I consider selling it. I then fix it and want to keep it for 100K miles more.

geordi wrote:

Toss the bottom half of the shroud and don't look back.

Sounds like a plan.

geordi · **Posted:** Tue May 26, 2020 12:49 pm

To isolate the harmonic balancer at this point -

Pull the fan since it is in your way. Get it and the shroud out if they aren't already. Now pull the serpentine belt,and you should be able to reach the balancer and unbolt it. (4) 10mm around the outside. If (when) the pulley doesn't want to come off, a BIG screwdriver against the left edge of the inner cover and wedged behind the pulley will pop it loose - Catch it to prevent it hitting the radiator and causing issues (leaks).

You can run the engine without the balancer on it for a while - I JUST worked on a CRD that had the balancer pulley WITHOUT THE WEIGHT on it running for about 30k miles! I wouldn't suggest that, but obviously it has happened.

So running it for a few minutes won't hurt anything. If it's still making the noise, then you have your answer. If not... Drive it around a bit to do the things where it usually makes the noises (speed bumps etc?) otherwise then that's probably the source. If the rubber is missing chunks, it is DEFINITELY the source.

bronco9588 · **Joined:** Sat Oct 29, 2011 8:17 pm **Posts:** 69

geordi wrote:

You can run the engine without the balancer on it for a while - I JUST worked on a CRD that had the balancer pulley WITHOUT THE WEIGHT on it running for about 30k miles! I wouldn't suggest that, but obviously it has happened.

She sounds great without the balancer. Damper comes back from Damper Doctor on Thursday. Thanks

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

bronco9588 wrote:

geordi wrote:

You can run the engine without the balancer on it for a while - I JUST worked on a CRD that had the balancer pulley WITHOUT THE WEIGHT on it running for about 30k miles! I wouldn't suggest that, but obviously it has happened.

She sounds great without the balancer. Damper comes back from Damper Doctor on Thursday. Thanks

Please let us know how it turns out. I'm thinking of preemptively sending ours to them, and would appreciate any insight you can give as to the quality of their work, etc.

Harmonic Balancer

Who is online