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wobbling pulley ruined crankshaft keyway

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I am sure that those with enough experience in subarus have found this to be becoming a very common problem. Someone pulls the crank pulley for whatever reason(timing belt/water pump etc.)and doesn't retighten the main crank bolt enough. Over time the pulley begins to wobble and ruins the pulley /the key /the timing gear and usually the crank at least a little sometimes a lot. I have bought three cars with this problem, the first without knowing. The others I actually got extremely cheap because the owners didn't know what the problem was with their car running like garbage. Turns out the wobble had happened which led to timing gear spinning and timing getting off.


There is a link somewhere on the usmb to a company selling a modified timing gear and pulley effectively locking them together. This is just an expensive alternative to just replacement of the oem parts if the key isn't ruined but if it is you are out of luck.


First get all the necessary parts from the junkyard. If you are lucky the keyway is only slightly damaged in this case use brake cleaner to get any oil residue out of the keyway and the crank bolt threads. Use Threadlock Quickmetal(find it online, expensive but worth it) to fill any gap in the keyway and key and reinstall everything. When putting the crank bolt back on use red threadlock or the strongest stuff you can find. Torque the bolt to at least 90 ft/lbs. Hold the engine from turning by placing a long bar in the torque converter inspection hole on the top passenger side of the tranmission to engine bellhousing. Don't try to use a strap wrench or chain wrench on the pulley, you will damage the pulley or won't be able to get as much torque on the bolt as you need.


My brother did this fix and his has lasted 60000 miles so far.


If the crank keyway is ruined, you don't need a new crank or new engine like the dealer or garage mechanic will tell you. Clean the crank and keyway well. Place the key in the slot (make sure it is in the right place if the keyway is really messed up). You may need to use a little tape to hold it in. If you have a welder you can do this yourself or take it to a welding shop. Run a bead of weld along the key just enough to fill in the ruined keyway. Do not weld the key into the keyway just run it along the key. If you tack the key in place knock it out with a punch. If the key gets welded in you can never replace the front seal or oil pump. It is not easy but can be done. Using a dremel tool with a reinforced cutting disc grind the weld until the timing gear slides on fairly easily but with a tight fit. Reassemble everything per the previous steps using the quickmetal and threadlock.


Yes this does entail using some tools you may not have but buying them will still save you a ton over the alternative options(new crank or new engine)

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