So this issue will require some detective work, sound knowledge, and hopefully a class action suit for people like me who have had this problem and lost > $15,000.
As many Sprinter owners know, there have been issues with harmonic balancers falling off and causing major issues and damage. I unfortunately experienced such a problem with a 2004 Sprinter that I bought used with ~94k miles on it. There is alot of background info, which may be relavent to the situation but I’ll try to explain as concise as possible:
At 104,599 miles, I had some transmission repair work done on my 2004 2500 sprinter (140in wheel base) by a certified sprinter mechanic at Christopher’s Dodge World in Golden, CO. In addition to the transmission repair, the mechanic attempted to replace a burnt out #2 glow plug. Upon trying to remove the glow plug, the glow plug broke off inside the head. They said it would cost about $3000 in labor to remove the head and retrieve the glow plug from the inside. I argued with them (and called the corporate headquarters) about doing the job for free, but I could only negotiate to have them do the job for 50% off. Later I learned that if the engine was warm when he attempted to remove the glow plug that it probably wouldn’t have broken off, but thats a separate issue and I can’t prove anything… moving on.
Several months later, after saving up $1500 and going almost the entire winter running off of 4 out of 5 glow plugs, I brought the van in at 107,242 miles to have the cylinder head removed to extract the broken glow plug. They did the repair, I paid them the money, and was off on merry way. As a side note, my coolant warning light started going off but the service provider explained that once the engine was warm the fluid would expand and the light would turn off (which doesn’t seem to make sense, since water is a non-compresible fluid… but what do I know?). That just seemed a little dodgy…
About two months later and at 109,099 miles, I heard a loud clacking sound from the engine and while attempting to coast the van to a safe place to get towed, the engine seized up. I had the broken van towed back to the dealership and the same mechanic that did the work earlier looked at the damage. Basically the engine lost timing because the crankshaft keyway broke, which of course caused the valve timing to be off thus smashing the valves, which in turn caused the camshaft to break in half as well. So the mystery, and why I need a 2nd opinion, is figuring out how and why the crankshaft keyway broke. The mechanic hypothesized that the bolt that attaches the harmonic balancer to the crankshaft (i.e., the crankshaft center bolt) had “somehow” gotten loose, which caused all the torque of the engine to rest on the keyway, which sheared off since it’s just a little sliver of metal used to line everything up.
Why did that particular bolt come loose, you ask? The mechanic claimed that when he pulled the head to remove the broken glow plug two months earlier, that he never touched the bolt because he kept the timing chain fixed on the crankshaft. Indeed, as other mechanics have mentioned, you can do this job without having to mess with the crankshaft center bolt (??). Nonetheless I have some secret video recordings (That I collected to document the whole case) that suggests that they might be lying. Regardless of if the dealership is at fault for negligence, there is an additional piece to the puzzle. Maybe other folks (particularly FedEx drivers) have experience with the crankshaft center bolt coming loose and causing major damage. I find it very strange that this particular crankshaft center bolt, which should be tightened to 240 lbs. ft., would come loose and not be addressed by Dodge as some kind of recall. However in 2006, Dodge sent out two service bulletins on Feb 25 and June 17, informing mechanics of a “Crankshaft Replacement Policy Change…” (Bulletin #09-003-06) and “New Crankshaft and Center Bolt Design” (Bulletin #09-006-06). The June 17th bulletin clearly illustrates the old and new crankshaft designs and after March 2006, all the Sprinters had the new design. Hmmm, so why would Dodge change the design? They must have recognized a problem with the old design, otherwise what was the rationale for the new design, right? Why not recall the vehicles? Why send out a service bulletin rather than telling owners that at anytime your crankshaft center bolt might come loose and then your engine is done? It appears to be a coverup on behalf of Dodge (owned by Daimler-Chrysler at the time of the accident, April 2011). When I asked the mechanic why he didn’t check the crankshaft center bolt for tightness, since it appeared that the health of the engine relied on the crankshaft center bolt being tight, he simply replied that it wasn’t part of the routine checks.
I have since argued this situation to Daimler-Chrysler (or at least what remains of them), posted the story on the Sprinter Forum, and even consulted with legal experts. To my dismay I have not gotten any straight answers or help, nor been called back by Click and Clack when I’ve left about 20 messages! 
Any help with this matter would be greatly appreciated. Sorry for the novel.
Thanks,
Dave
Thanks for the clarification on the meaning of the service bulletin. Probably nothing shady going on, but it does make one wonder given all the horror stories with that particular bolt coming loose.