200 Tdi crank damper mount shot - what to do

One of your American cousins has messed up and needs your help (No - we didn't invade any country. This is just an engine problem). I am running an early 1990s 200Tdi in an ex-MOD 110. I've run and loved this truck for 30+ years. Driving along on a remote overland trip and the Woodruff key that secured the harmonic damper sheared off. I kept driving it as it was still spinning the water pump and alternator (but with a helluva awful noise whenever I had to stop). Pulled it all apart and went to replace the damper as the inner tapered surface on the old one was chewed up. When the new damper was secured it does not run true but wobbles about 3 mm per revolution. Tried a second damper with same result. I have taken a bunch of measurements and finally concluded this -> I chewed enough off the tapered crankshaft extension that the damper now bears against the timing belt drive cog before becoming tight on the crank. The only thing I can see to do is pull the crank and either replace it (likely, given that Turner has a new one they recommend) or TIG weld a bunch of material on the old crank and re-grind it. Only other thought I have it so make a thin brass shim (a cylindrical thin shim) that I would then use to make up for the lost taper. Seems like a long-shot but might be worth trying before pulling out the engine to replace the crankshaft.
A second but related question -> The engine runs fine with about 130k on it. No smoke at all once warm and is a strong puller. If I have to swap the crank what else would you do while you have the engine out on a stand? Main bearings, con rod bearings, rings, piston pins? Timing belt and tensioner of course but what else?

I would bodge up whatever I could to save taking the crank out.
Maybe lightly take an angle grinder with a flap disc to the crank taper as the engine is ticking over? obviously not for to long as no water will be circulating.

lynall said:

I would bodge up whatever I could to save taking the crank out.
Maybe lightly take an angle grinder with a flap disc to the crank taper as the engine is ticking over? obviously not for to long as no water will be circulating.

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It is worth trying most anything. I hate to pull an otherwise good engine and tear it down for this problem. I found I can get coiled brass shim stock. I am thinking of running the engine and trying the grind approach, but need some info.

(1) To grind I have to keep the damper off and hope the Woodruff key keeps the timing belt cog in place (Or does it have its own separate key?) That's scary because if the cog flies off I wreck the engine.

(2) Realistically I will have to grind with the front of the timing case off in order to get to the part of the crank - that means the water pump is off and the coolant is drained. Maybe 30 seconds of run time before shut down.

(3) Does anybody know how far proud of the crankshaft end the harmonic damper should be on a unit that is not messed up?

wileycat said:

It is worth trying most anything. I hate to pull an otherwise good engine and tear it down for this problem. I found I can get coiled brass shim stock. I am thinking of running the engine and trying the grind approach, but need some info.

(1) To grind I have to keep the damper off and hope the Woodruff key keeps the timing belt cog in place (Or does it have its own separate key?) That's scary because if the cog flies off I wreck the engine.

(2) Realistically I will have to grind with the front of the timing case off in order to get to the part of the crank - that means the water pump is off and the coolant is drained. Maybe 30 seconds of run time before shut down.

(3) Does anybody know how far proud of the crankshaft end the harmonic damper should be on a unit that is not messed up?

Click to expand...

I had in my mind it was just the damper itself, but if all that has to come off I would say new crank time, or crank rework time.

Item number 4, two of, so I would have to assume cam drive gear has its own separate key.

That looks consistent with what I can see with the timing belt cog still in place. I have a new idea - I can pull off everything down to the timing cog and use a long belt of sand paper to encircle the rough part of the crankshaft extension and hand sand about 180 degrees of the diameter at a time, then manually turn the engine a few degrees at a time and keep repeating. That will give me a smooth surface - but likely not one that has the exactly correct taper any more. I then try the extrudable brass shim stock and see where I get.

Likely won't work but worth a try. In any event - I promise to report back and thank you for any and all input.