harmonic balancer came off crank shaft help?

[interested!]

Hi! had the very same problem and fixed it cheaply,
FIRST, get the car on ramps at the front , strip to gain acess to timing belt and crank gear and remove. next ( in short ) measure and reduce crank to parallel to smallest diameter -its gone conical .I made a machined tube to min dia with a sliding pin in crank thread to maintain parallelism -using fit/mark/file--fit/mark/file --fit/mark/file -mark made by twisting to leave high spot mark -took a few days to reach the gear-. repair keyway with two part metal epoxy to refit key . THEN : machine out balancer to fit sleeve( very light drive fit ) c/w slot for key ( only make slot to cover fit depth!!!!--this must be a sliding fit on crank (only do this when you know the exact OD of the crank ). fit balancer c/w new key to crank, finally I drilled through crank/sleeve/balancer and fitted a bolt( head and thread removed ) to maintain anti spin ( its all been reclaimed ), I refitted mine with loctite when I was happy with the fit. check timing mark with piston tdc using a dti on piston crown and reassemble using new crank seal and new timing belt etc. .WELL worth the effort , repaired mine 10 years ago and still going strong -easily removeable for new belt change 8 years later.