The Car engine cannot even move a fraction, if the engine shifts at all, that is the piston change position even by the parts of Millimeter, it will cause similar difficulties, taking a Crank Pully Off, on a sensored engine is quite difficult, as you have to lock everything down so there is absolutely no movement, or the Timing will be knocked out; this can be reset, but you need the right Diagnostic Disc for the year and model, also it is even more crucial with a Diesel engine as most times if the timing is out on a Petrol Engine, it would probably try to start, spit backfire,misfire, but at least you can reset it.

Taking any part of a the Main Engine drive off to replace from fly wheels through to crank shaft or even changing sometimes a belt, moves the engine a Micro amount, but it is enough to cause issues, and in Diesels it will knock them out all together. So along with not disconnecting the Battery, you have to LOCK the engine down so it cannot move at all, which is not always the easiest.

Let me know how you get on; sorry but I have been unwell lately so I have not spent alot of time on site.

Jimmy

 

If so then I can't see how it won't start unless as you say there was no timing marks etc on it.  Generally these pulleys will only go back on one way with a woodruff key etc so any timing should be maintaned.  If its just driving ancillarys, then engine timing shouldn't be affected.

 

What caused it to break?  Can't see how that sort of component would wear out?

 

Ahhh wait a mo, yeah I've heard of that. 

 

Oil contamination causing the rubber/plastic to disintegrate?  Or just heat/cool cycle?