New 2.8TD motor or crankshaft overhaul?

My surf trip to Lancelin was destroyed on Saturaday when the battery and sub-tank lights came on while cruising up the Mitchell Freeway.

RAC man diagnosed very quickly and order me a tow home. The bolt holding the crankshaft pulley had loosened and the belts were all sitting out of line, so no alternator, powered steering or water pump. So the car got a little warm in the 200m i drove to get it off the freeway. This cracked the overflow / expansion tank to relief some pressure.

The mechanic this morning said the crankshat pulley bolt should NEVER come loose, it is held firm by pins etc etc. The end result is that the crankshaft is probably mashed up. The options are some extensive work on reconditioning the crankshaft, or it may be cheaper / easier to replace the motor, which has done 350k and was working well and strong with no signs that something like this was coming...

Does anyone have any experience/knowledge of these issues and how much overhaul or a new motor might cost?

Crankshaft pulley bolts come loose all of the time on these engines a common fault.
You would really need to inspect the damage you may be lucky and just have a broken keyway.

Broken / mangled keyway and damaged pulleys :(
Need the engine out, new crackshaft, pulleys etc. Mechanic says about a few other parts worth replacing while the engine is out, such as timing belt, water pump, hoses.
Am thinking may be cheaper on labour to just transplant an engine.

What engines are a direct bolt in to a 1998 GU 2.8TD?
If possible, can I upgrade to a newer 3.0TD on the same running gear/ecu?

Some people fit rb25's rb26's the gearbox is different on the 2.8 you should be able to find a good second hand crank pulleys etc cheap enough i sold one for $100
plenty of 2.8's about with cracked heads and good cranks even whole engines from conversions about check ebay or post in the wanted section..

I just found same problem.

It's a nightmare I had same issue, I feel for you. But if not to bad it's repairable.