Yes, you can change the
chain by attaching the new one and fishing it around, but that does not get any sprockets or guides. The labor time to install a chain on an old MB 617 diesel is on the order of 40 hours! Yes, they do last a long time, typically 300k miles or so, but come on! 40 hours!??? A TDI, even at 60k intervals at even 5 hours apiece, you'd still spend less time!
I find people afraid of belts simply because they do not understand them and hear about some horror story. But most of these cars simply don't have timing belt problems so long as they are cared for correctly and serviced correctly. Granted neither myself nor any engineer cannot overcome what some idiot may do to a car. And trust me, even idiots can buy tools. I've seen it all too often. I have had to redo dozens of botched jobs on all sorts of cars, there are some real winners out there
It is no secret that there are more stresses on a diesel's timing belt versus the average gassers timing belt, but just because it is a belt does not automatically make it failure-prone. German engines with belt driven OHC seem to be less tolerant of neglect, whereas the Japanese engines are much more forgiving. And their scheduled changeout is a pretty long time as well.
At Lexus, most of our cars have a 90k interval, and even after that, the belts typically are still tight and have no visible wear on them at all. But a German engine, even Volkswagen's own 2.0L gasser, after 60k miles has obvious wear patterns, is substantially stressed, and sometimes can look quite frightening.
Bottom line is, the timing belt has its advantages and disadvantages. I feel, since I don't see much problems inside the envelope of scheduled PM, the advantages far outweigh the converse. And a TDI, even an ALH, is not
that difficult of a job to do by anyone worth his salt. Try hanging a belt on a four-cam double VVT-i Toyota V8! Then bend over for the whopping $1500 repair bill!
My Jetta is nearly 14 years old, it was born in December of 1990. It will be getting its 6th timing belt soon. It costs me about $100 in parts (yes, the old IDI diesels are cheaper than the TDIs), and will take me a couple hours. It has never broken a belt, jumped a tooth, ate a tensioner, or anything at all. In fact, it still runs as good as it did when it was new. If I had bought a '91 Sentra instead, its chain would have been wiped out by 150k miles, and would have taken me about 15 hours to change it out, and a chain/guides/tensioners/gaskets/seals/etc. would have cost me around $350. And I still would have had a Sentra
You do the math. I'll gladly keep my belts.
