D40 timing chain job

[xkkat]

Hi Guys Just started stripping down The inner guide of top duplex chain has failed .It was just sitting there both mount bolts tight bit mount s had cracked off at the bend in the steel backing plate Now looking at the crankshaft pulley centre bolt Its TIGHT! Would like the forums advice here Tried all my rattle guns on the 19mm bolt whats next can anyone help Regards to all Terry