Another tale of a broken crank - I rebuilt the 36 HP motor in my '58 Ghia with an aftermarket cast crank. Accelerating from a stop sign one night, I got the same "bang!" and drove slowly to the nearest gas station to see what was up in a lit area. The pulley moved in and out freely, but besides some rattling when it ran, the motor was smooth and reasonably powerful. I had it towed home, and redid the rebuild with a forged VW crank. It's been fine for 20 years now.
I keep the broken crank pieces on my shop shelf to remind me to use OEM - always - if possible! Chuck Kuecker On 5/22/2011 10:43 AM, Mike wrote: > If this was me, I'd take the heads off (at the very least). > > See what there is to see inside there (valves, cylinder walls, etc.) > > Take the flywheel off and you'll be looking at the front of the #1 main > bearing thrust surface. If you can see where it's wearing into the case, > rotated or can move it at all, the case is damaged. An align-boring with > thrust cut may not fix it if the damage is excessive. > > The distributor drive pinion gear can move up and jam the crank, if the > engine was rotated while the distributor was removed. > > The crank can be broken completely in 2 pieces and still rotate! This > happened to a friend of mine that was trying to outrun a train to a railroad > crossing. He was driving his '62 sunroof bug as fast as it would go. He > made it, but the loud bang he heard was the crank breaking in 2, apparently. > Surprisingly, he drove it the rest of the way home and it ran ok, but didn't > sound well. He grabbed the crank pulley and it went in and out a great > amount, so he pulled the motor. The flywheel endplay was normal! Yikes!? > Upon teardown, the crank web was found to be cracked completely through in > the middle! It still ran! How's that for VW reliability? > > If the last time your engine was running was not accompanied by a loud noise > and sudden stoppage, then it likely lacked oil pressure, or ran too hot and > seized up (quietly, while parked), either the bearings, the rings or both. > > Sorry to say, but a thorough inspection and teardown seems to be in order > here. > > Mike B. > > > -----Original Message----- > From: asad ishaque > Sent: Sunday, May 22, 2011 8:18 AM > To: vw mailing list > Subject: Re: [vintagvw] Motor locked up. > > > Hello all, > > Continuing the uncovering of the mystery...... > > Well, I had a long chat with the old timer Mechanic whom I was inviting > home and also took the starter motor which came off the bug to him. We > examined it together and deduced that there was nothing broken or missing > off it. We reached the conclusion that we would have to pull the motor to > get to the bottom of things. As the clutch felt 'normal' to press and > release, we concluded that the likely thoery of a loose and dropped thrust > bearing pin would not hold in our case. > > So on the 20th of May 2011 with the odometer showing 29597 Kilometer > (yes, its a Kilometer speedo!) the two of us pulled the motor in our > driveway. The findings were: > > 1. Leaky main oil seal indeed. Lots of oil under the engine but just a light > skim inside the bell housing. Only the engine side of the clutch plate had a > light coating of oil. > > 2. Clutch plate lining was good. However, the four rivets holding the center > part were coming loose. So we averted another disaster. > > 3. Nothing wedged between the flywheel and bell housing. > > 4. Now the motor sat on the ground and was inspected. It just would not > turn. We decided to be gentle with it and put a 36mm socket with a standard > handle on the gland nut (no breaker bar). It would not turn. Just a bit of a > nudge and it came free!! It proceeded to turn anticlockwise without any > issues but again at about the same point, it would not go any further. > > We deduced that for about 20 degrees of the revolution, it does not go > round. You can take it the other way round but not thru the 20 degrees. > > Another thing we noticed. I had stuffed a plastic bag down the intake > manifold with the carb off. During part of the revolution, the plastic bag > would come flying off!! It should mean that at least one intake valve was > not closing. > > I have yet to reexamine the valve train with the engine sitting on the > floor. I am guessing I missed something. I should rotate the engine by hand > and see how the valves operate. Maybe its a broken intake valve?? > > 5. We examined the oil cooler after taking it off. The old timer said it > *might* be chocked though he was not sure. He said wed run kerosene oil thru > it to make sure. An old school method of checking is to assess the weight. A > heavier oil cooler points to a chocked one. I have yet to run oil thru and > check. Dont think its likely as we had put on a brand new oil cooler during > the rebuild and Ive kept the oil clean. Still, $hit happens. Who knows. > > The engine now sits on the driveway floor. I shall get my hands dirty > again probably tomorrow and let you know the findings. Any thoughts to check > other things??? > > Someone said it may be a broken crank but I tried to rotate the engine > with one hand on the crank pulley and one on the flywheel. I cant feel any > relative play which probably must be there in case of a broken crank. > > Also a suspect is a broken or bent con rod. > > I consulted another VW mechanic who said it is most likely a spun number > one main bearing which would need me to repair the block. Hope not. > > Thoughts, ideas????? > > Best regards, > > Asad > Karachi, Pakistan. > > > > > > >> From: [email protected] >> To: [email protected] >> Date: Thu, 19 May 2011 00:01:01 +0000 >> Subject: Re: [vintagvw] Motor locked up. >> >> >> Thanks to all of you for the warm welcome back!! >> >> I am most grateful and amazed that I/we (my brother and I) were >> actually being missed by many. This feels like returning home after a long >> time to family, our VW aircooled family! >> >> My Hotmail account is no longer my primary email but I do read the >> posts every once in a while and do wish I chime into the discussions more >> often. Can share a lot of the local VW happenings here which would be of >> interest to all. >> >> I read all comments and pondered over. Seems like the two top >> possibilities are something wedged between the flywheel and Bell housing >> (maybe like you say a TO bearing clip which came loose when I pushed the >> car while in gear to disengage the starter motor??). Or something to do >> with the Valve train assembly. Have still not had time to dig deeper into >> this mystery as my work hours are odd nowadays. I plan to crawl under the >> car and take a good look with the valve covers off. I did try to turn the >> crank pulley good though not really in the opposite direction but it did >> not budge even a fraction of a millimeter. >> >> I dont know why but have been having this 'gut feeling' it would turn >> out to be something stupidly simple rather than something as horrid as a >> broken crankshaft. Lets see, shall share definitely. >> >> I have invited an old timer Vdub mechanic over to my place tomorrow and >> would see what he has to say. Id like to inspect the valve assys before he >> comes to narrow things down. >> >> Now I'm sitting planning a bit ahead. I did have quite a few things >> lined up so if I do need to pull the motor, Id have plenty to do. Im >> thinking maybe this is an opportunity thrust upon me, very politely, by >> the VW gods! The car lives up to its nickname of 'Trusty', not breaking >> down on the road to leave me stranded! Below is a list of 'things to do' >> if I pull the motor: >> >> 1. Replace leaky main oil seal (have a German replacement in my stash, >> just arrived from Canada) >> 2. Fix some mysterious exhaust leaks. Seem to be from one of the joints as >> all components are solid. Bug has stopped fweeming lately. >> 3. Toss out the J tubes we had used as no decent heat exchange boxes were >> available. Now I have a pair of good heater boxes in the attic. >> 4. Inspect the clutch. Have brand new Brazilian clutch and pressure plate >> in my stash (a lucky local bone yard find from an unfinished project which >> ended up with the scrappers. Half price!). >> 5. Maybe, just maybe pull the heads off to fix some oil leaks and fix a >> single stud which was bad after the overhaul several years ago. This was >> perhaps the only corner we cut, after great contemplation back then. >> 6. New piston rings etc if no 5 happens. >> 7. Have nice push rod tube seals too in from Canada which can go on if no >> 5 happens. >> 8. Put in a new starter bushing. Btw, folks may find it interesting that >> some local Dub specialists can change this with the engine on the car. Its >> a neat trick I can describe. >> 9. Maybe I'm forgetting something?? But I know if I put my hands into >> this, one things going to lead to a lot of things!! >> >> This is not all. I have a 'spare' 1967 vintage engine and gearbox in >> my stash too. Engine can be bolted right on till the current unit gets the >> needed TLC so car is not off the road for long. >> >> Also, have some issues to sort on the gearbox itself. The nose cone >> has miles of play in the hockey stick. The brass bushing even comes loose >> and wiggles around. Sloppy shifter to which I'm used to, unfortunately. >> Sometimes the reverse gear slips to neutral. Any thougths whether this is >> due to a bad reverse or may be a consequence of the hockey stick play?? >> How can I be sure, without tearing the whole box open, something which >> gives me nightmares as not familiar with the intricacies. >> >> Some questions: Can I swap the nose cone off the gear box with the >> unit on the car?? I have a small collection of nose cones now. How hard is >> it to take the gearbox off?? Its a swing axle 68 bug. Would the rear wheel >> alignment get disturbed if the gearbox is taken off or played around >> with?? I also must change all the three mounts while I'm at this. >> >> All thoughts shall be highly appreciated. >> >> Best wishes and warm regards to all, >> >> Asad >> >> Karachi, Pakistan. >> >> >> >> >> >>> From: [email protected] >>> To: [email protected] >>> Date: Wed, 18 May 2011 04:08:27 -0700 >>> Subject: Re: [vintagvw] Motor locked up. >>> >>> my friends 63 panel bus had "locked up" right after he turned off his >>> engine. upon pulling engine we found a throwout bearing clip wedging the >>> flywheel. reinstalled the throwout bearing with new TO clips and driving >>> it >>> everyday 20 miles each way. >>> >>> -----Original Message----- >>> From: [email protected] >>> [mailto:[email protected]] On Behalf Of No Quarter >>> Sent: Tuesday, May 17, 2011 3:30 PM >>> To: Air-Cooled Volkswagen Discussion List >>> Subject: Re: [vintagvw] Motor locked up. >>> >>> Hello Asad! Haven't heard from you in a very long time so I'm glad to >>> see >>> you're still with us! >>> >>> It is entirely possible that something has fallen into the flywheel gear >>> teeth and wedged itself between the teeth and the bell-housing. >>> >>> I would just pull the engine and while it's out, fix that starter >>> bushing in >>> >>> the transmission. >>> >>> Then to remedy your hard start issues with the increased resistance in >>> the >>> wiring causing the solenoid to not want to activate, go here and read up >>> on >>> this rather cheap fix: >>> http://www.thesamba.com/vw/forum/viewtopic.php?t=421220 >>> >>> Keep us posted! >>> >>> NQ _______________________________________________ vintagvw site list [email protected] http://lists.sjsu.edu/mailman/listinfo/vintagvw
