been trying to sort out a friends bay as he has a problem of the flywheel falling off the story so far removed engine to replace oil pump, in doing so the flywheel and clutch were removed refitted engine and after a few minutes the engine was making a odd part rattle part vibrating noise remove engine and find flywheel loose check crank. dowels and flywheel and refit fine for a day (hour or so of testing) and then same noise again remove engine and find flywheel loose check crank etc and dowel holes are no longer round strip engine, replace crank, dowels and flywheel + all the bearings etc refit engine and start up after about a minute the same sound again remove engine and find flywheel loose check crank, dowels and flywheel again and all is well refit flywheel, tighten up with the biggest breaker bar and scaffolding poll we could find (to hell with the correct torque) + add some locktight for good measure drove for about 15 minutes and all was well tweaked the carb linkage and started again funny noise, part rattle part vibrating noise we have now run out of ideas between me him and his dad and uncle and these 2 have about 100 years between them messing about with VW engines so does anyone have any ideas why the flywheel keeps falling off
do you mean the clutch bolt or the big one holding crank to flywheel ? the big crank to flywheel one was reused
they don`t need locktite , as that affects the correct torque . i`m guessing something is wrong with the flywheel dowels ?
did you use the same flywheel bolt from the first crankshaft and flywheel on the second crankshaft and flywheel?
I've learned that dowels are there almost only for lining up properly. And when the bolt is tightened once, it should not be used again.
I am with Paul weeding and zed I always use the same nut ,I have even overtighten the nut and it has broke in half, so be careful... are you sure the thread in the crank is good...
for what it's worth, TTY (torque till yield) bolts should not be reused. What happens is when you tighten them down, then go x number of turns past that, they stretch..... The stretch is a controlled spring - basically you yield that high strength steel and once you have done that you cannot do it again, because they will break. Either upon install or during use, neither of which is worth the trouble. Found this,, is it just nonsens ?
It sound as if you have changed every thing apart from the bolt and the flywheel. So i would guess its one of these. The flywheel could be out of balance or as others have said the nut threads have warn.
I'd be slightly alarmed by wear on the dowels or dowel holes, as on a type1 I believe these actually transmit the power to the transmission.
you can re-sure some stretch bolts, it depends on the application and the bolt, but the crank bolts isnt a stretch bolt. try taking the o ring out of the back of the flywheel and cvheck to see if the flywheel it rocking on the crank it may have a burr or something also check the bolts isnt bottoming out( it shouldnt ) but it will stop the flywheel from being secured. when the flywheel is on turn the engine by hand to see if the flywheel is out of true anywhere.
have you actually tightened it to the correct torque, or just assuming you've got it right because you used a big bar? Type 1 torque can be a pig to get right without good kit