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Aqua Puttana 11-16-2016 04:21 PM

Harmonic Balancer Information
1 Attachment(s)
Harmonic Balancer Condensed (somewhat) Information

Search: Repair replace remove install T1N OM647 OM612 vibration damper pulley sheave dampner

There has been discussion as to whether the Harmonic Balancer HB should be changed on a schedule.
My opinion.
There are pitfalls and traps for DIY HB proper replacement.

If the operator(s) is aware and listening for odd noises from an engine then periodic replacement is not what I would suggest. If the ring loosens and makes noise, then removal of the failed ring allows full operation until repairs can be effected.

If the truck is operated by less than mechanically inclined, engine aware operators (aka: the clueless whose idea of maintenance is adding fuel) then periodic replacements may have substantial benefit.

Thanks goes to all contributors. :thumbup::thumbup:

If you are on the road and discovered the loose ring, the ring can be removed to allow driving many hundreds of miles without issue. REMOVE THE RING. Pressing on with a loose ring has danger of further damage. Removing the ring gets you home.


Originally Posted by Aqua Puttana (Post 495727)
If you need to press on there may be a response to a loss of rubber bond on the harmonic balancer. The ring can be removed and the Sprinter driven with the ring missing.

At least it worked for Alexk243. I personally would keep my speeds/rpm down a bit. I have no data.


Originally Posted by alexk243 (Post 495257)
So the outside ring on the harmonic balancer is loose and spinning freely... Appears the bolt is tight... How much time do I have? I am 500 miles from home.

Sent from my HTC One using Tapatalk


Originally Posted by Aqua Puttana (Post 495265)
How high is up?

The proper answer is that it needs to be repaired. If it comes loose it can do a bunch of damage.

One possibility. If the ring will pass over the serpentine belt pulley. Remove the serpentine belt, remove the separated ring, and re-install the belt.

That should get rid of the balancer failing.

Were I to try that I would keep my speeds down to 55 mph to keep engine rpm's down. That said, there may be rpm ranges where more vibration is noticed than in others. If discovered I would avoid those ranges.

There must be many people who have run the T1N with a partially failed harmonic balancer which wasn't doing the job.

To be clear. I have never tried what I suggest above. I have no idea what the risks of trying it may be.

Good luck.



Originally Posted by alexk243 (Post 495482)
So I have no reception and Wi-Fi but I guess I reached the same conclusion that you guys did. I drove 50 miles on it to an awesome diesel mechanic shop and they took the belt off and removed the ring. They also made sure the harmonic balancer was on there tight. After that (10 mins or so haha) I headed back and made the last 500 miles or so safely. Noticed a lot higher vibration as I approached 70 mph so stayed well below that.

You can see the ring removed on the floor of the shop by the driver door.


Thanks for the quick responses guys. Sorry I could only check it when I was at a place with Wi-Fi

Now my next question is what harmonic balancer is recommend for replacement? I am fine paying more so this does not happen again. Any thoughts?

As always, clicking the blue arrow icon within any quote box will take you to the original post/thread.


Originally Posted by Aqua Puttana (Post 582024)
All you need is a proper tensioner tool or just a 17mm 12 point box end wrench to release the tensioner, remove the belt, and remove the loose ring. The tensioner has a cast in 12 point fitting.

If DIY isn't possible any decent small shop can do it. Refer them to the link that I provided above. That will allow you to get back home without any major expense. The repair can be scheduled once home.


Here's an artistic rendering of the belt routing by a talented local artist.

Attachment 89491]

The general information for repair starts here.

General comments.
There are at least a few failure modes. The rubber mounted balance ring can separate or become loose. The spokes of the Harmonic Balancer HB can crack/fail. The retaining bolt can fail. The bolt failing generally results in crank nose or key related issues.

Periodic inspection of the HB may reveal rubber separation or spoke cracks before critical failure. It is generally accepted that the double belt HB for rear air conditioning is more prone to failure.

A separated/detached ring on the Harmonic Balancer HB can be removed to allow using the Sprinter until the proper repair can be effected. Members have driven many hundreds of miles after removing a separated ring. I personally would keep the speeds/rpm down a bit. I have no idea of the consequences of operating without the ring, but would be willing to risk it as oppoesed to being stuck.

There have been some problems with aftermarket HB's. The general recommendation is to stay with OEM or at least OEM supplier brand.

The bolt and washer must be replaced. Do not re-use either of them. Many repairing/replacing the HB don't change the seal. At about 15 bucks for the part it is not a bad idea to do so while everything is apart.
Torque Spec = 240 FOOT/POUNDS (325Nm) plus 90 degrees assuming a grade M10.9 bolt.

Part Numbers
(Verify before ordering.)

PULLEY-CRANKSHAFT - Some possible selections.
Dodge 5103998AB
DODGE 05103972AB, 5103972AB
MERCEDES-BENZ 611 030 03 03, 611 030 17 03, 612 030 00 03, 647 030 01 03

Bolt =
The 2004 bolt aka screw was originally listed as (Dodge) 05073696AA or MB N000000001884 (?)

Washer =
The 2004 washer under the head is (Dodge) 05080005AA or MB A6049900040

Seal = Dodge 05073675AB (?) or MB A0239978447
or National/ Timkin seal 710289

Key = The new key design part # 05170759AA (will sometimes fit a damaged nose end).
Note: Apparently the key design was changed for 2006 models. I don't know the exact crossover dates. It is probably listed somewhere by VIN number.

There are many good pictures in this thread.

T1N Harmonic Balancer Failure

A small collection of some of the available information in no particular order.
As always the original post/thread can be accessed by clicking the blue arrow icon within any quote box.

I'll start with this.

Originally Posted by Aqua Puttana (Post 495265)

Originally Posted by alexk243 (Post 495257)
... How much time do I have? I am 500 miles from home.

Sent from my HTC One using Tapatalk

How high is up?

The proper answer is that it needs to be repaired. If it comes loose it can do a bunch of damage.

One possibility. The ring will pass over the serpentine belt pulley. Remove the serpentine belt, remove the separated ring, and re-install the belt.

That should get rid of the balancer failing.

Were I to try that I would keep my speeds down to 55 mph to keep engine rpm's down. That said, there may be rpm ranges where more vibration is noticed than in others. If discovered I would avoid those ranges.

There must be many people who have run the T1N with a partially failed harmonic balancer which wasn't doing the job.

To be clear. I have never tried what I suggest above. I have no idea what the risks of trying it may be.

Good luck.



Originally Posted by gggGary (Post 467532)
Guess it's not really emphasized in this thread but there are 2 maybe 3? harmonic balancer failure modes;
The garden variety rubber separating failure discussed here, typically gives some warning vibration and noise. Often the smooth outer weight exits with little ancillary damage?
The Broken spokes failure. Is this closely related to rear air, or maybe high electrical loads? Now the belt and sharp broken part can do some hurt as loose parts thrash about.
Key/keyway failure, the rarest but most damaging failure, typically requiring crankshaft replacement.

That sound about right? [Yes.]


Originally Posted by abittenbinder (Post 407266)
I have seen more than a few harmonic balancer bolt failures in Sprinters over the years.

The bolt in your '04 is the 10.9 grade version bolt. In most of those failures the pulley bolt had been improperly torqued or reused during a repair or rear A/C crank pulley retrofit.

The correct torque procedure is a 2 stage operation using a NEW bolt. First the 240 ft/lbs, then an additional 90 degrees of rotation.

This brings the new bolt to it's yield point and theoretically results in an infinite fatigue life.

Ignoring the second stage during tightening could cause a short fatigue life, reusing a old bolt could result in a shorter life as well.

You should be able to grind a small slit in the remaining [broken] bolt shank face using a Dremel tool and back out the shank [stub] with a screw driver.

Doktor A


Originally Posted by Midwestdrifter (Post 467614)
I would like to point out that keyway failure is almost always a secondary affect caused by a broken or under torqued pulley bolt.

Make sure you follow the tightening regime exactly! "Good and tight is good enough" is bad!


Originally Posted by lindenengineering (Post 502680)
Don't forget the stepped cone abutment washer that goes on the balancer pulley arr!

The steeped undercut provides a vital clamp load on the pulley and it becomes work hard over time.

You can't take short cuts and risks with this attachment.


Originally Posted by lindenengineering (Post 481951)
The key failure is caused by the damper coming loose on the crankshaft nose or stub!

Being a highly torsionally stressed area the key cannot be a substantial item otherwise it too would be a stress raiser causing potential crank failures!

Hence it is merely a locator device for the damper itself on the shaft !

The secret if you want to call it that is the very high torque applied to the retaining bolt and stepped cone washer which in effect is creating a crush style clamping condition.
Obviously then, the repair modis operandi is to recreate the factory crush condition by using a new bolt and washer plus of course a factory damper which has the correct shore hardness element.


Originally Posted by bc339 (Post 405504)
Two sources for getting a flywheel lock -

The official MB tool goes for around $135.00

KTC flywheel lock for $20.00 - http://www.amazon.com/Mercedes-Benz-.../dp/B0089PY4XM



Originally Posted by Midwestdrifter (Post 499173)
On the very bottom of the bell housing there is an opening where you insert the [flywheel] lock. The lock itself engages with two bolts which are currently installed in the bell housing they are almost vertical. [The lock also engages the flywheel starter teeth which keeps the flywheel in position while the HB bolt is torqued in.] Back the bolts out and install the lock onto them. The hole itself is where the starter would go if you had a manual transmission sprinter so there should be a small opening where you can stick your fingers in and feel the teeth on the outside of the flexplate. if you look at the lock it has a series of small teeth which engage in the teeth on the outside of the flexplate. it's a bit of a brain stretch but you should be able to figure out how it aligns based on those.

The photos on this Amazon listing give you a rough idea of how the lock installs.


Aftermarket HB.


Originally Posted by WAYNERODD (Post 256488)
I have bought & installed several of these. The aftermarket part is a complete failure! All of them failed (outer ring came off) in less than 6 months.


Originally Posted by Merwins (Post 402842)
Well! lesson learned the hard way, my 2006 with 240,000 just let go of it's 2nd harmonic balancer, the 1st was at 235,000 and unbeknownst to me at the time I went to my local CARQUEST auto parts and ordered the replacement, now I know about the made in China junk, it lasted less than 6000 miles before coming apart while stopping at the mailbox at the bottom of our driveway after doing around 100 miles plus yesterday, talk about good timing! I made it home. I'm not happy about having to take it apart again but thank goodness the guys at Europartssd.com here in SD have all the needed parts in stock! I my opinion, in order to correctly torque the bolt you can't do it without removing the radiator, intercooler, etc... to gain easy access to the front of the balancer and bolt, neither the 3/4" drive monster torque wrench or breaker bar will fit between the radiator shroud and front of the pulley so it all comes apart...again.

My 2nd one came apart after only 5000 or so miles, Dorman made in China junk. I didn't know any better at the time, but don't get anything but the factory replacement. The original one lasted 230,000 plus and made the funny noise and took a while to figure it out, never separated, the replacement Dorman one made noise for about 30 seconds before coming apart and taking out the serpentine belt! Europartssd.com had all the factory parts in stock here in town! I know what I'm doing today! again!


Originally Posted by PATECO (Post 471977)
So the Doorman balancer I bought and installed in October self destructed yesterday. The balance ring went flying out the bottom of the engine bay taking the belt with it while I was driving to work. Managed to drive two blocks home and park it, without further issue.

Where would you suggest getting an OEM Balancer. I don't want to have to do this again next year.


Originally Posted by NateV (Post 502679)
Go to http://europarts-sd.com will have everything you need.
Best prices, excellent service, OEM parts. They specialize in Sprinters.
They ship Fedex so you'll have your parts in the next day or two.

Access to change out the parts.


Originally Posted by lindenengineering (Post 497859)
You don't need to remove the rad'!
In fact you don't even need to remove the fan and cowl either if its the rack or over a pit!

But if you are having "bash" for the first time, then remove the fan & cowl and there is plenty of room to change it out.

Put a piece of carton or packing box cut off over the inner radiator matrix to protect the fins.
Professional mechanic time is 1.5 hours
See how you get on and all the best !:thumbup:


Originally Posted by Aqua Puttana (Post 497913)
If you decide to swing it [the radiator] out there is an outline here.




Originally Posted by lindenengineering (Post 496081)
Plus you will need a torque wrench with excess of 240 lbf ft capacity plus a long knuckle bar!
To angle tighten it. AND a 27 mm [1 1/16"] deep socket!


That's enough from me for now. Do a search or click on the blue arrow icons for additional information.

:cheers: vic

Aqua Puttana 11-16-2016 06:59 PM

Re: Harmonic Balancer Information


Originally Posted by talkinghorse43 (Post 36186)
Several instances of this a couple years ago were discussed on the yahoo sprintervan forum. I'd go there and search & read.

Also from the '03 service manual:

(1) Disconnect negative battery cable.
(2) Remove accessory drive belt (Refer to 7 -
(3) Install retaining lock for crankshaft/ring gear
(Fig. 43).
(4) Remove crankshaft center bolt and washer
(Fig. 43).
NOTE: If hub of belt pulley/vibration damper is
tight, use puller # 8940 to remove. DO NOT tilt
puller when in use. Grooves of the puller must
mesh fully into the slots of the belt pulley.
(5) Remove the belt pulley/vibration damper (Fig.
1 - SPECIAL TOOL #8932
NOTE: If grooves can be felt in the belt pulley/vibration
damper during inspection, the pulley/damper
must be replaced.
(6) Inspect hub at belt pulley/vibration damper for
wear grooves.
(7) Replace front crankshaft seal.
NOTE: Align parallel key, fix in place with grease.
Turn to ensure the slot is aligned with parallel key
in crankshaft.
NOTE: Front crankshaft seal must be replaced
before installing the belt pulley/vibration damper.
(1) Position the belt pulley/vibration damper.
(2) Install crankshaft center bolt and washer.
Tighten bolt in two stages. M8.8 bolt to 200Nm (148
lbs. ft.) then 90, M10.9 bolt to 325Nm (240 lbs. ft.)
then 90.
(3) Remove the retaining lock for the crankshaft/
ring gear (Fig. 43).
NOTE: Inspect accessory drive belt for wear.
Replace as necessary.
(4) Install accessory drive belt (Refer to 7 - COOLING/
(5) Reconnect negative battery cable.
(6) Start vehicle and inspect for leaks."



Originally Posted by http://www.thomsonrail.com
On the head of each bolt are two numbers separated by a decimal point, the
full list includes ten grades from 3.6 to 14.9 but in plant and machinery only
grades 8.8, 9.8, 10.9 and 12.9 are normally found. The bolt head should also
have a code - normally two or three letters - indicating the manufacturer.
Usually the markings are on the top of the bolt head but sometimes they are
on the side.
The first number gives the breaking strength of the steel in the bolt. In round
terms it is in 10’s of kg per square millimeter of the bolt.
For example, a grade 12.9 bolt will not snap until every square millimetre of
the bolt cross section is carrying a load of at least 120 kg. Similarly a grade 8.8
bolt will not snap until it is carrying a load of 80kg per square millimetre.
A bolt will begin to stretch before it finally breaks, the second number on the
head of the bolt indicates how much of the breaking strength the bolt can
stand before it starts to stretch.



Originally Posted by skill3 (Post 258163)
I just finished the HB install yesterday. I just removed the fan with clutch and the serpentine belt. The HB bolt was really hard to break loose, but I had a younger, stronger helper do that. Even though I had the correct HB puller, the HB slid right off. The seal popped out easily. I installed the new seal, I wish I had the proper installation tool, but it went flat and flush. The fun part comes when you torque the HB center bolt. That's 240 FOOT/POUNDS plus 90 degrees. Luckily I had access to a 3/4" torque wrench that was 36" long and the stronger helper. I did have the proper flywheel locking tool which is a must. For anyone that needs the HB puller and flywheel lock tool, I'm trying to figure out a loan system for forum members. Let me know what you think. Send me a PM.


Originally Posted by plumber1 (Post 263679)
I changed the balancer and front crank seal on my 04 3500 today. The rubber had completely failed and the outer ring was getting ready to come loose and make a big expensive mess of the front of my engine. I found that 3- 1 1/4" flat washers ($2.00 each) and the old (or new) balancer bolt make nice seal installers, and they dont cost way too much money as most of the special tools to work on these incredible vehicles do. It is not self centering so you have to guide the washers onto the snout of the crank but works nicely and easily after that. The bolt should turn easily and the seal should press in easily. DO NOT FORCE IT AND MAKE SURE THE seal starts in the hole in the front cover and the first two washers are not pinched against the end of the crank prior to using the bolt and washer to press the seal in place. I used a large flat screw driver with the flat part of the blade resting (not scraping to cause damage) against the crank snout, a small block of wood as a fulcrum to protect the front cover and oil pan lip, pried gently on both sides of the crank (180 degrees) from each spot and one time a little harder and the seal popped right out. The puller I used to pull the balancer I have had for years. Something like it should be available at your local auto parts store. It has 3 legs and a pushrod looking piece that bottoms out in the bolt hole on the puller and crank. The removable legs it has were a big help to get it in place quickly. I am not going to say what i used to hold the crank but it was not the MB or miller tool which would have been easier to use and probably safer than my method. I am attaching photos of the puller i used for the balancer and seal remover and installer. Auto Zone had the front seal in stock at their hub store near me. I used the National/ Timkin seal 710289 ($9 and change) and got a Dorman balancer from Napa next day for $230. I had to go to a local dodge dealer to get the new bolt, it was $12.99 (next day) where freightliner wanted $18.99(next day). I used a torque wrench to gain the initial torque spec [240 foot pounds] and a breaker bar with a 3' or so piece of pipe to get my 90 degree final. Hope this helps someone out there. I hate paying out the nose for tools and parts just because they are "$pecial".:crazy: I also enjoy the challenge of making tools to do jobs that require them. Here are some pics that may help


Originally Posted by Missouri Blue (Post 291200)
Let's say that you bought a Sprinter with rear A/C and two compressors. Let's also say that the rear A/C wasn't working, but you wanted to repair it so it would be working when you took a month long trip with family in tow this summer. For kicks, let's also say that you thought (based on the savvy advice of the forum and Dr. A) that this would be a good time to replace the harmonic balancer as a preventative measure. Sure your not the preventive type, "If it ain't broken don't fix it" you've always said, but a harmonic balancer failure far away from home because you've been running that rear A/C while pulling a trailer doesn't sound like fun.

This is what I thought.

I bought the balancer ($188 plus $45 shipping) from Ebay UK.
Off-brand fly wheel locking tool ($30) worked flawlessly
Bolt, washer, and seal (@$30) Berry Dodge

All was going well until I tried to remove the balancer. The bolt came out, no problem, but the balancer would not budge... not at all. Thankfully, I was with a friend who welds. He made a low-profile puller that would attach around the pulley for the aux. a/c. With a lot of torque and tapping from behind the balancer began to move... slowly. When it came off there was no key. No key on the end of the crankshaft no key in the pulley... No key. When I looked back in the hole I could see that the key had been sheered off at one time. The date stamp on the pulley was 09/09/08. The previous owners must have suffered a failure resulting in a sheered off key. The repairer glued/JB welded the new pulley on!

At this point I was stumped. I did not want to glue the new pulley on. We found some half-moon key stock and began to file. We filed and fitted, and filed some more. Finally our little half-moon fit in the open slot and the new pulley went on. Before torquing to spec I back the bolt out and checked to make sure our home-made key had not moved... it hadn't. Torqued the pulley to spec. 242 ft./lbs. and another 90 degrees, put everything back together and started it up (after a broken fuel line, but that's another frustrating story).

I was expecting a relatively easy job, but the unknown previous failure really messed things up. The end of the crankshaft is not perfect, but not to the point of needing to be replaced. If you find yourself in this situation the new key design part # 05170759AA would fit in the keyway left available by the sheering off of the old design key.

At the end of the day (well, two) I have a new Harmonic Balancer installed, rear SCS frigette A/C working well, and a rebuilt HP pump from Dr. A installed, (oh yeah, a new fuel line that I wish wasn't new as well).

NickConrad 05-19-2018 06:59 PM

Re: Harmonic Balancer Information
Hello everybody, I just wanted to to thank all of you guys for the extremely helpful information on HB so far. The outer ring on the HB of my 2006 just separated. I found the links to the OEM parts from Europarts-sd but I had a couple of questions about which bolts i needed as well as which seals I should buy. I see that there are two types of bolts one for late 2006. What is the best way to figure out which part to order? I tried looking on the bolt itself for the marking but I can't really get in there to see. I've tried looking up my VIN Number a few places but couldn't get to one that would tell me mfg date. I'm thinking about just buying both just incase. So about the seals, do I need the rear seal as well or just the front? Any help with this would be amazing I really want to start driving my sprinter again soon. Thanks guys.

I have a 2006 3500 Sprinter with the one AC

Midwestdrifter 05-20-2018 12:32 AM

Re: Harmonic Balancer Information
I am not sure on the bolts (the difference is that one comes with a washer separate?, and maybe the torque value varies?)

There is only one seal to replace here. Referred to as the front main seal, or front crankshaft seal. The rear seal is between the engine and transmission, and is not part of this job obviously.

NickConrad 05-22-2018 01:16 AM

Re: Harmonic Balancer Information
Thanks Midwestdrifter, I'm glad I didn't buy both seals! I'm going to just start taking things apart until I can get in there to look for the bolt number.

lindenengineering 05-27-2018 05:03 PM

Re: Harmonic Balancer Information
Don't forget to use a new cone step washer! There is a reason for that!

NickConrad 05-29-2018 09:55 PM

Re: Harmonic Balancer Information
Good looking out. There wasn't a lot of information about the parts out there and the parts were even harder to track down. Thanks to everyone who has posted about this one. I quickly realized this job had to be done exactly right or suffer catastrophic consequences. :cheers:

scotto 08-05-2018 05:44 AM

Re: Harmonic Balancer Information
want to add my experience. i narrowly avoided crankshaft replacement. i bought my sprinter with 165,000mi on it. around 172,000, i started to hear a noise from the engine while on the highway when the rpm got to 3000. if i backed off a little it would go away. i spent some trying to figure this out and eventually it made itself obvious. the serpentine belt came off and there was oil everywhere. what happened was the balancer was loose and the front main oil seal failed as a result and also threw the belt off at the same time.

once i got it apart i figured out why. i put a standard length 1/2" ratchet on the balancer bolt and it unthreaded with almost no effort. it clearly wasnt torqued to spec. i found out that the balancer had been replaced by someone who didnt know the proper procedure and just tightened it "good enough". the keyway was damaged, that was the noise i was hearing on the highway, the balancer was vibrating on the crankshaft. the woodruf key wasnt broken, but was worn. i replaced the woodruff key and filled the worn area on the keyway with epoxy to reform the keyway to its original size and shape so the new key would sit in there like it should. the epoxy is fine for this repair because the keyway is not holding the balancer in place. it is only locating it on the crankshaft. the high torque of the bolt keeps the balancer from spinning on the shaft. many miles after this and all is good

just wanted to add this so maybe you will know if you have a similar symptom and you dont know who worked on your van in the past that this is something to check. this isnt the first or last thing i have found that has been incorrectly repaired on this van.

Njclimber 12-29-2018 11:19 PM

Re: Harmonic Balancer Information
1 Attachment(s)
What is the difference between the old style bolt (10.9) and the new style (1150)?

Njclimber 01-01-2019 12:40 AM

Re: Harmonic Balancer Information
Answered in another thread:

Class 10.9 is an Alloy steel that has been quench and tempered.

The 1150 means the bolt has a 1150 megapascal ultimate strength. This is non standard (between 10.9-12.9). The new bolt is stronger to reduce fatigue failure, and provide higher holding torque. This is needed for the newer crank gear design with single keyway.

Q: Just random thought: I understand both bolts are different strengths so wouldn't they have different torque specs?

A: The same torque will result in different stretch between the two bolts. I am not sure of the specific reasoning for the replacement.

Q: What if I use the 10.9 bolt?

A: I am about 90% sure it would be fine to use the 10.9 bolt, but that last 10% involves the bolt breaking after 75k miles...

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