Well, I had a chance to get at the balancer tonight, and it turns out the crank is NOT broken after all! Now that I see how it all connects, I see that it was not likely that the crank was broken... The bolt holding the balancer to the crank was finger tight; I suspect that was part of the problem. The part of the balancer that slips over the crank broke apart. There is also some kind of sleeve that came out with the balancer pieces. I also discovered that the crank has quite a bit of end play...but methinks I might be able to put the car back together to run it around here for the rest of the summer...but this is probably a big wake-up call to do some major overhaulin' or replacin' of the motor...
Lucky you! You had mentioned that the car started in your other thread ... don't think it would have started with a broken crank ...
Yeah, the more I though about it the more that seemed unlikely to me too. I envisioned that somehow maybe the end of the crank had broken off. I doubt that happens very often at all. I'm not used to seeing this type of failure I guess.
The balancer is easy. Unfortunately you will need to pull the timing cover to replace the front seal.
Yep, it was stock. I am wondering if the loose bolt was letting it wobble on there and maybe contributed to it flying apart?
Probably a "speedy sleeve". Used to repair a worn shaft, in this case, the balancer seal surface. Used them several times on big trucks in different places..... I don't know about that.....I ran a CAT diesel in a truck for 2-3 weeks before I found out that the crank was broke. It started and ran fine, only had just a small bit of vibration that was noticeable in the clutch pedal, and a noise when you shut it off, that sounded like it was coming from the clutch-bellhousing area. I thought I had lost a spring or lever on the clutch or pressure plate. Turns out it was broken on #1 rod journal, you could pry the balancer forward and back 1/2", but the timing gear train still worked...... and the engine ran fine.
I was right:bananaman Glad it is something less minor than a whole engine rebuild..... Still a 331 is calling your name!!!!
Yes sir, you were indeed. There IS a lot of end play of the crank, so I think I can still make a good case for a 331/347 ...but I might be able to put things back together so I can drive around here in the meantime though...
Go 331 smoother engine......less chanceof any wear issues..... if you want to go racing then do the 347.....
It could have been loose causing vibration and the balancer to break. Also, check any belt drive accessories such as A/C or P/S. If the bearing is locking up in one of those, it could have put stress on the balancer. I saw that happen in a sbc truck. Seth
Just more reason to buy a decent balancer...Something better than they sell at the local parts houses. http://mmb.maverick.to/showthread.php?t=46505