has anyone heard of a crank shaft that didn't need a bolt to hold on the harmonic balancer? i thought as tho a bolt broke off inside but the guy at the machine shop said that some cranks didnt need a bolt, such as this one. my block is from a 68 corvette and the machine shop guy said that the crank was not original, but in fact a very good one, meaning newer and stronger. i just hope hes right when he said it didnt need a bolt. has anyone heard of this before?

 

You don't need a bolt until the time it decides to shake itself loose. It is a press fit on the crank's nose, but it is a good idea to hold it in place with the bolt.

 

i seen those fly off at 7000 rpms.....thats on built engines, so worries

 

any suggestions how to press the harmonic balancer on? its quite a snug fit

 

with out the bolt, sounds hard.....dont use a hammer

 

Get some carbide drill from a machine shop supply house and drill the broken bolt out (do not use a carbide masonry drill), tap a hole one size larger. and get a hardned bolt to fit & put the balacer back. Otherwise pull the crank out & take it to a machine shop. How did you manage to break the bolt??

 

yea, sounds like the mechanic broke a bolt off in there, do what pete said, and make sure you use a hardened bolt. you dont want to shoot the balancer through your hood, and your motor would suffer from the vibration/sudden unbalance.

 

they didnt use a bolt in the front of the crankshaft until 1968, All new aftermarket cranks have the bolt hole.
If your crank is a factory one you can check out this site and see what it came from by the casting #
http://www.mortec.com/cranks.htm

As far as installing the Ballancer without a bolt the only way is with a hammer. if the motor is still on the stand you can wedge something between the back of the crank and stand to hold the crank forward so you dont hurt the thrust bearring