Harmonic balancer

mrcolin2u

2005 Sprinter
I've been reading threads about the HB failing and I'm concerned if this is something I need to do on my 2005 sprinter as preventative maintenance.
The pulley seemed fine when I changed the serpentine belt last year and as of now with 90,000 miles the engine sounds fine.
Is this a job my fellow T1N drivers here think is an absolute must ?

Cheers
Colin
 

ECU

Well-known member
when it becomes a problem, replace it. Mine went at 300,000, ten years ago.
 

alexk243

KulAdventure
It is not particular easy to fix on the road, but if it does go bad while driving you will notice and you will have some driving time left before failure if you remove the outer rind (if loose) and torque down the HB.

Its not cheap and the job takes a bit of work and special tools so like ECU said above you can wait till it becomes a problem or if you are really worried about it you can just replace it. Depends how far you travel away from a shop/garage and how inconvenient having the van down for a bit is.
 

Nautamaran

2004 140” HRC 2500 (Crewed)
My 2004 held well past 190,000 miles. Ring removal took ten minutes: belt off, pry off ring, belt on. You can go quite a while with the ring missing.
A less common occurrence is that the crank bolt loosens and the whole pulley moves. If there are signs of this then park the van - it will destroy the keyway if you continue driving for any distance. (most will just find the failed rubber and loose ring)
I replaced the HB/crank pulley last weekend. Took me 3-1/2 hours, and was an excuse to buy a BIG torque wrench, a low profile seal puller, and a flywheel lock. There is enough room to get this done from below without taking the radiator apart.

-dave
 
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Visian

2006 T1N 3500 158" wb
Mine just failed at 170K miles. I started hearing a ringing/rattling sound and saw that the metal flywheel/ring had separated from the rubber isolator and slipped backwards... ratting against the crankcase. Following advice here, I un-tensioned the serpentine belt and was able to slip the ring out.

Truck is currently being repaired... the tech had an issue with how tight the bolt on the end of the crank is. He broke his flywheel blocking tool and had to buy another. Ideally you would find a tech with the official MB tool, which you cannot buy... but my tech said his new tool worked fine.

To answer your question, I would not replace the balancer until it failed. You can drive it a while without the flywheel ring (I have this on the most expert of advice). Take it to a qualified shop with the right tools, especially a 250 lb/ft torque wrench.

I replaced the original water pump and fan clutch while it was apart, along with the idler pulleys and serpentine belt.
 

JDixon

New member
My 2004 held well past 190,000 miles. Ring removal took ten minutes: belt off, pry off ring, belt on. You can go quite a while with the ring missing.
A less common occurrence is that the crank bolt loosens and the whole pulley moves. If there are signs of this then park the van - it will destroy the keyway if you continue driving for any distance. (most will just find the failed rubber and loose ring)
I replaced the HB/crank pulley last weekend. Took me 3-1/2 hours, and was an excuse to buy a BIG torque wrench, a low profile seal puller, and a flywheel lock. There is enough room to get this done from below without taking the radiator apart.

-dave
Are you able to get fan off without taking radiator off?
 

Nautamaran

2004 140” HRC 2500 (Crewed)
Are you able to get fan off without taking radiator off?
Yes, though you need the tool to counter-hold the clutch pulley, and need to remove the plastic cowl to access the centre bolt.

That said, I did the whole job from under the van without taking the fan off - I had just enough room in front of the pulley for my regular depth 27mm socket and 250 ft.lb torque wrench head (I don’t have rear a/c, just the single serpentine belt pulley).
Pulling the seal with the fan in the way requires a low profile tool: I used a Lisle 58430, and you won’t have room for a cheater pipe from underneath, so have something planned to brace against to get the last 1/4 turn of bolt.
 

Aqua Puttana

Poly - Thread Finder
...
Pulling the seal with the fan in the way requires a low profile tool: I used a Lisle 58430, and you won’t have room for a cheater pipe from underneath, so have something planned to brace against to get the last 1/4 turn of bolt.
Maybe the factory tire jack, or even a floor jack under the ratchet or breaker bar handle? At that point the specification is degrees, not torque.

vic
 

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