Ok here it is. I did a 12V conversion had quite a few miles on the conversion since its been done. I noticed a weird vibration popped the hood and OMG my balancer is all over the front of the crank! Took out the pick up for the tach and everything. So I get a new balancer swap it out runs great no vibration at all a month later BAM!! 2nd balancer is gone! I checked the run out on the front of the crank off the nose and off the journal wher the seal goes around. Have zero runout. I put a bolt in the front of the crank turn engine over and grab ahold of the flywheel at same time they both move together.So I come to the conclusion from what I have done the crank is not bent or broken. What do you guys suggest drop the pan and pull the mains to do a visual check to see if the crank is not broken? I need some advice not sure what to do next. Thanks
If you had a broke crank it would be extremely obvious. Either front of crank would wobble all over the place by moving it by hand or it would have a horrible knock when engine is running. What kind of RPM's are you turning this engine? High RPM's will take out the balancer.
See I thought the same thing that it would be noticeable. I have talked to a couple guys that said they have seen 2 where the crank was broke and the trucks ran perfect. One did develop a knock the other didnt. They told me they were broke in the number 2 webbing. This truck is not a hi PRM engine it hasnt seen over 3500RPM's
Yes sir I did use new bolts. Chased the threads with a tap used brake cleaner to clean the holes blew them out with compressed air and loctite. A practice I got into a long time ago.
If the crank is broke, its not going to go anywhere...
regardless of where it breaks, it still has to maintain movement at the front of the crank to drive the geartrain to keep it running. and if that happened and the front couple cylinders could manage to keep the engine running, the rear cylinders would have piled up into the valves and killed it anyways LOL
It is possible that the crank is twisted/bent causing some wicked torsional vibes.
Is the whole balancer getting hammered off the crank, or is it just pounding out the rubber isolator and the outer ring is coming off?
The bolt holes where the balancer bolts to the crank are oblong. I dont get a wicked torsional vibration at all. I'm just trying to eliminate all possible things that could be wrong before I put it back together. I dont wanna be doin this again balancers are not cheap. Sorry man had to vent a lil bit
if the bolt holes are hammered out, thats likely the result of worn bolts and/or not properly torqued
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