Apologies firstly, this is very non VW (I admit its actually Vauxhall) but its very much an engineering tech question and help is needed.
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The bolt pictured is M18 x 1.5, so a damn strong thing, its to hold the front crank pulley / damper mass onto an engine, its tightened to a torque then an angle so is obviously a stretch bolt and should be replaced not re-used.
GM no longer provides this bolt and when they did it cost £35, owning old VWs is easy compared to GM cars, this engine was produced until 1994 and already most of it is unavailable and its difficult to keep one on the road.
Questions, firstly, the head is stamped 10.9, a 10.9 bolt of the correct size is available for a few quid each on ebay.
Is it fair to assume any 10.9 bolt will have the same yield point and can therefore be used for this job as a stretch bolt, or is there something special about a stretch bolt compared to any other even with the same 10.9 stamped on the head.
Second question, thoughts on successful re-use, I was thinking torque as standard then just a little angle tighten to add a touch of stretch, I realise that going to far could mean failure. Thoughts please.
The bolt pictured is M18 x 1.5, so a damn strong thing, its to hold the front crank pulley / damper mass onto an engine, its tightened to a torque then an angle so is obviously a stretch bolt and should be replaced not re-used.
GM no longer provides this bolt and when they did it cost £35, owning old VWs is easy compared to GM cars, this engine was produced until 1994 and already most of it is unavailable and its difficult to keep one on the road.
Questions, firstly, the head is stamped 10.9, a 10.9 bolt of the correct size is available for a few quid each on ebay.
Is it fair to assume any 10.9 bolt will have the same yield point and can therefore be used for this job as a stretch bolt, or is there something special about a stretch bolt compared to any other even with the same 10.9 stamped on the head.
Second question, thoughts on successful re-use, I was thinking torque as standard then just a little angle tighten to add a touch of stretch, I realise that going to far could mean failure. Thoughts please.