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turndriverside
03-20-2013, 06:15 PM
Hey Guys,

Before I begin, I should state that I am a complete newbie when it comes to Sprinters.

Over the weekend, the harmonic balancer came off on my 2006 Sprinter, and ruined the crankshaft, from what my mechanic tells me. Is there any hope of replacing just the crank shaft alone, or would I be better off getting a rebuilt engine?

Any help would be appreciated.

Thank you,

Sebastian

autostaretx
03-20-2013, 09:28 PM
The quickest and best answer is to call Dr Andy Bittenbinder at 412-366-6165 (near Pittsburgh)
He'll be able to give you the best advice on the choices available to you...

good luck
--dick

lindenengineering
03-20-2013, 11:15 PM
Hey Guys,

Before I begin, I should state that I am a complete newbie when it comes to Sprinters.

Over the weekend, the harmonic balancer came off on my 2006 Sprinter, and ruined the crankshaft, from what my mechanic tells me. Is there any hope of replacing just the crank shaft alone, or would I be better off getting a rebuilt engine?

Any help would be appreciated.

Thank you,

Sebastian

Sebastian
assuming the rest of the engine is good there is no reason why you shouldn't replace the crank including bearings in isolation simply by inverting the engine and following the approriate proceedures.

I have done it many times on various engines including the Sprinter.
Just leaves me to ponder how did the front pulley AND the harmonic balancer centre bit all fall off!
I have come across the outer element ring coming adrift a few times so that it sounds like Santa Clause is a coming to town, but the whole lot!:thinking:
The crank bolt is torqued up to something about 220lbft then a further 1/4 turn to take it to stretch. It has to go some to fall off!
Makes me grunt when winding it up in the frame!
Dennis

talkinghorse43
03-21-2013, 01:39 AM
Just leaves me to ponder how did the front pulley AND the harmonic balancer centre bit all fall off!

Haven't heard exactly why this happens, but more than a few have been reported on this forum (usually on '04-6s with rear A/C and 2 compressors). I can imagine it could happen if excessive force were exerted on the serpentine belt through a frozen tensioner arm - or through excessive tension on the second compressor's drive belt. Since the balancer's connection to the crank is not in the same plane as either belt's path on the balancer's pulleys, excessive force on the belts could act on this lever arm to tilt the balancer. If that tilting force exceeds the residual clamping force of the bolt, then the bolt will stretch further and loosen. A loose bolt will eventually result in a failure. Also, several harmonic balancer failures have been reported where the spokes of the balancer have failed - these were with the single compressor balancer.

On the other hand, the good Doktor replaced my harmonic balancer because I thought I saw cracks in mine, but when I had it on the bench and cut it apart on many planes, no cracks were found. However, I did notice that the surface the crank bolt washer bears on was painted. Seems to me paint could creep with time and temperature and result in a loose bolt.

skydiver007
03-21-2013, 11:49 AM
Mine separated from the rubber and sounded like Santa. Andy (Doktor A) had her fixed and running in a day. Mine broke loose but there was just a bead of rubber holding it from shredding the belt. Crank was fine and he said the balancer rubbed most of a timing mark off, but otherwise no damage.

I drove all the way from NC to Pa to work and heard the noise, but I could not find what was causing it until I was in a parking lot and got under it and saw the rind just flopping around.

I got lucky.

Boater
03-21-2013, 03:05 PM
I have read other stories here of HB coming off - some people have taken a gamble on just replacing the HB even though the end of the crankshaft is damaged - I think you are right on to change the crankshaft.

Sprinter engine is no different to any other in that respect, maybe better tolerances than some and maybe more electronics to unpug and re-plug than a more traditional diesel but it still uses plain bearings with replaceable shells that any engine builder would recognise :D:

Aqua Puttana
03-21-2013, 03:22 PM
... - I think you are right on to change the crankshaft.

...
I disagree without evaluation. I think Dick's earlier suggestion to get Doktor A involved is good advice.

A crankshaft replacement is no small job. It is also not inexpensive. Any time you disassemble a good running engine engine and re-assemble it there is a risk that things may not go tegether quite right. If based upon his experience and examination Doktor A said that the crankshaft didn't need replacement, that would be good enough for me. Within reasonable distance, I'd think it is worth the cost of delivering the Sprinter to Andy or some other known professional for that evaluation.

Once Andy has the Sprinter my confidence would be high that it would be made right. There's been more than one thread here relating stories of major repairs going awry by less experienced mechanics.

My opinion and worth everything you'll never pay for it. I hope it all works out to be the less expensive option for the OP. vic

ECU
03-21-2013, 06:54 PM
I posted these pictures...
http://sprinter-source.com/forum/showpost.php?p=223074&postcount=182

At 530,000 miles this guy broke a crank bolt. The pistons look so good, they are going to leave the rings in place.

http://sprinter-source.com/forum/attachment.php?attachmentid=49976&d=1359605517
http://sprinter-source.com/forum/attachment.php?attachmentid=49978&d=1359605517

chads
03-22-2013, 12:59 PM
You may want to check out your altenator and your idler pulleys,tensioner etc.
If the alternator pulley dosn't freewheel in the backwards direction and got locked up.
At times of heavy decelleration the load exceeds the strength of the crank key, that is of questionable quality,and can shear the key and cause the nut to spin off etc.

Not sure if the A/C pump has the same setup but you may look into that too.
I would think a good PM item to do on oil changes.

From what I understand the earlier tins had a flimsy key that was just a piece of bent sheet metal as a key in the keyway slot. I rember scanning this somewhere along the line and checked the serial # on my engine and I am fortunate to have the newer model crank that has a better keyway setup. I'm thinking they changed somewhere in mid 2006.

If your ordering parts look up by block sn to get the right ones. Depending on how bad it looks you may be able to clean it up and put a new HB on.
Chad

Aqua Puttana
03-22-2013, 01:02 PM
... I'm thinking they changed somewhere in mid 2006.

If your ordering parts look up by block sn to get the right ones.
Chad
and I have a 2004.... :cry:

Time will tell. vic

Boater
03-26-2013, 03:15 PM
I disagree without evaluation. I think Dick's earlier suggestion to get Doktor A involved is good advice.



It is good advice, but I'm 99.5% sure that reading up on HB problems a while ago Doktor A was quite specific that if the end of the crankshaft in way of the HB and key is in any way damaged the crankshaft should be replaced, not repaired. Later, I may remember to search out the thread..... (I think the OP of that thread repaired it)

Of course I assume by the statement 'ruined the crankshaft', that damage in this area had been noted by inspection, rather than an assumption about possible hidden damage....