crank key all messed up, need help!

so I pulled my harmonic balancer off today to check the crank triggers following my stuttering problem, and i noticed the keyway between the crank and gear is all messed up, the gear has moved about a millimeter, causing my missfire and all my other problems, so now what do i do? the old key is messed up and the key way in the crank is now slightly bigger than what it should be. so the old key just slops around. my best bet right now is looking like cleaning up the key way carefully with a dremel and trying to find a slightly bigger key to fit. any other suggestions? any help appreciated!

Had the same issue on my previous car. I ended up getting a new key, and gear. The slot where the key fits was damaged a little, so I had a buddy with a welder tac weld the key into place. Then grind down the welds in order for the gear to slide over.

 

I have heard some people using JB Weld in place of a welder and it held up. Not saying this is the best option, but could be a temp fix if you don't have access to a welder.

this is not a huge problem.

 

the key does not hold the crank sprocket in position. the bolt does.

the key locates the the crank sprocket until the bolt gets tight enough.

and the wear in the key way allows the key / sprocket to slop in the ''un-bolt' direction. the crank will be right on when you reinstall.

 

replace the key, the sprocket and the pulley, used is ok if they are not messed up. reassemble and torque the bolt to 135 ft lbs. torquing to less than that will cause the same problem again.

 

when you torque the bolt, do not hold the crank pulley with a chain wrench. hold the flex plate (auto trans) or fly wheel (manual trans). there are several ways to do this. search or ask.

I had the same issue just before I replaced my motor, I freaked out because it wallowed the end of the crank shaft a little bit but it was an easy fix..you can find the woodruff keys at auto part stores they will sell them in various sizes. I filed the middle sized one flat on the rounded side because I wanted it to hold rather tightly.

the engine spins clockwise correct? if looking at the keyway with it facing up the left side is the side that is slightly messed up, its been slightly enlarged not allowing me to even position the gear correctly, ive cleaned it up but not sure what I should do from here. the jb weld is sounding like a good option to re-establish the position needed, they use it at a local machine shop in there axle castings to fill voids so if its good enough for military spec MRAP's it should be good enough to hold the position of the key until I can get the bolt torqued back down correct? I have new keys but im just extremely nervous of throwing the timing off seeing as how it appears this is what did it in the first place.

I'm notsure the key way being damaged would be enough to throw it out of timing, if the damage is that bad it will be because of the crank timing gear, that should probably be replaces regardless of the crank key way damage. I can see the use of jbweld with minimal scarring of the crank seeing is that its a heat treated and pressure quenched part..the design of the gear is that so if the woodruff key is compromise the next part in line doesn't cause catastrophic failure of the crank. The gear is a lot softer than the crank for that reason.

the engine spins clockwise correct? if looking at the keyway with it facing up the left side is the side that is slightly messed up,

correct.

 

but when you apply torque you will tend to move the sprocket, and key to the right, as you tighten it. no worries. there is no slop in that direction.

 

i had this failure on a 93 lego. the shop used a ''never let go'' thread lock. and i drove it until i wrecked it with out trouble. they also replaced all the timing components so i would be good for 60k miles.

 

you can put what ever you want in there. but the simple reality is that if you do not line up the sprocket correctly before the whatever dries it will never be right. and if you torque it before it dries then it is not really helping to hold it in place when torquing the bolt.

 

again, if you line it up correctly and torque it to 135 ft lbs you will not need anything else. the bolt does the work if it is tight enough.

 

and as you have already learned, if the bolt is not tight enough, the key way will not last long. it will fail. it is not designed to hold the sprocket in the correct position when the engine is running. it is only intended to locate the sprocket correctly until the bolt tightens enough to hold it.

alright, thanks for all the help, should have the car back on the road soon!