Well I started the car up today and noticed the car had a loud knocking to it and when I open the hood the belt was not spinning so I shut it down immediatly. So then I narrowed down to the balancer bolt had backed out well, I took off the balancer and the key on the crank shaft which spins the balancer is gone! it broke into small pieces! I have no idea how to go about fixing this! all i know is im out of a vehicle for who know how till i get this fixed. Merry Christmas to me right!

 

lol that sucks there goes christmas your gunna need to get a new one sucks sorry man

 

12623085 is the part number for the key. Unfortunately, if it has gone and let the crank timing chain sprocket spin as well, = valves bent etc etc, it will be cheaper for you to get a replacement engine from Morad or locally from the wrecking yard; engine destruction may have occurred....

 

i thought on these engines, the crank gear had a keyway on it and just the crank pulley used a seperate key. If the pulley spun, it still may have f'ed up the crank. To the OP, were you in the engine at all, have you ever pulled the crank pulley??? Those bolts dont just back out for no reason.

 

That is true the bolts dont do that for no reason; lightweight pulley can cause that, improper assembly and torque, etc etc. only one key shown in the parts break out....the key shows it locates the balancer, the build book says:
"Slide the integral harmonic balancer/front
pulley on the crank with its pointer located
on the TDC position (this will allow it to
mate with the oil pump drive) and torque the
NEW bolt (GM P/N 11589123) to 76 ft-lb
(100 N-m) and twist it 125 degrees (+/- 4
degrees). Apply engine oil to the bolt threads"

if the pulley is gone the oil pump etc etc oh the horror of it all. This sucks: Buy new motor, install.

 

if that key is gone, it wont damage the engine, it will just kill all the accessory drive items.

 

huh? the crank sprocket drives the cams. opens the valves in time. if the crank sprocket loses its key it wont turn and in turn the cams dont move. the crank is rotated by the starter motor, the valves dont move? Big crash piston to valve.

lets hope it didnt happen.

 

john im trying to understand this but just can't see it. How would the broken key interfere with the timing of the cams...

The way i see the OP's problem is the "key" breaking off the crank thus not being able to turn the crank pulley. The gear inside should still spin with the crank and still turning the cams...Unless the key sits in a notch through the crank sprocket.

 

he is thinking that the crank gear and the crank pulley use the same key, which is not the case. The key is welded to the crank gear and only the crank pulley key is removable.

 

So in the event the key is broken, a new key is possible because one can buy a new crank gear.

 

yup cause john doesn't know anything about these motors. lol

 

yes, but if this keyway broke, then severe engine damage is possible.

i have only torn down 1 LSJ and i remember that the key was welded on the crank gear and the pulley had a seperate key.

 

That's why im sitting here like wtf?
Im willing to bet when he reinstalled the crank pulley he didn't line it up correctly. I did this but I noticed the pulley was spinning very out of line and quickly fixed it. Upon removal, it was damn near stuck on the crank and the inside showed signs of incorrect install.

 

Thanks for all the input and I just had a headgasket replaced which is why this could of happened and from what I have read the motor is fine it started for the short period just had a very slight knock to it which I was told is because the harmonic balancer was not doing its job.. Now if I understand correctly I can get a replacement key for the crank pulley as long as no other damage is suspected and how does someone go about doing this can this be done with the engine in the car? whats the part number for the crank key?

Edit: forgot to mention Half of the key is still on the crank on the other side of the front cover but none remains for the pulley to grab to

is this the correct part number? half of the key is still there, the balancer side is where its gone. do you have the pn for the crank seal? while I am there.

 

11589123 bolt with captive washer
12609467 seal

 

ok been here done this lol, the cams run off the crank shaft so does the oil pump and the water pump simple right? ok if the key insert breaks as they do from time to time mostly from improper torquing of the crank pulley bolt, either a portion of it keeps the chain sprocket running or it doesn't. if the whole key insert is gone good night...............if it just broke off a piece all you loose is the oil/water/charge/sc. and heres the shitty part if it broke off chances are it took a chunk off the crankshaft with it, so either way prolly need a new crank or a new motor. merry christmas.

 

I remember that entire **** but couldn't find pics or the thread. JBP pulley remember that pos?

 

yah that was rods car i believe, but this also happened to me with a used motor i swapped in.

 

and thanks Jimbo for the handy dandy pdfs so I could call out the right part numbers. No pdf for a complete motor tho' that's prolly where this story is heading....

 

I really doubt the motor is gone, being that It started and idled fine. I just think the accessories werent powered. We will see though plan on getting it towed monday to the nearest shop for further invegistation

 

Get some pics when you're out there. I want to see for myself.

 

no problem, just a good find from the interwebs.

might not be, depends on if the chain gear spun freely or stayed with the crank. but have a very close look at the crankshaft when you pull the front cover off. if theres a gouge replace the crank, used ones on ebay are like 200 bucks most of the time.