Crank pulley fell off. How to prevent??

[cnc]

In putting the EA82 timing belts on, you have to reinstall the crank pulley. Sounds easy enough. I put some blue Loctite threadlocker on it and screwed it in, then used a ratchet to beef it down pretty hard. Thought that would be fine. Sat for a day before starting car. Plenty of time for Loctite to set up.

 

Started car and let it run for a half hour, to see if anything would go wrong. Sure enough, started getting hot, but the fan was going around (too slow, it turns out) and a funny scraping sound started, followed by the brake warning light. Shut it down immediately and investigated.

 

The crank pulley nut had backed off but was still engaged in the threads. Put car in 5th and used a breaker bar to retighten pulley nut. Checked with torque click wrench and it was 76 ft-lbs or more, per spec, now. Drove fine on a trip.

 

My consternation is this: There is no positive lock on the crank pulley. It depends upon friction by the big crank bolt only. That seems odd. There is no taper I can see. And, the direction of rotation is such that any load on the crank pulley, like the alternator, A/C pump, water pump, and brake pump all try to unscrew the crank bolt. I'd expect to see a Woodruff key or something to positively lock the pulley from rotating, and the crank bolt is just there to keep it from moving outward. Is this right? Makes me nervous to turn on the A/C, knowing that I'm adding to the load and possibility that the crank pulley will fall off while driving. With the engine out, I can hit it with a manly-man's rattle-gun, but not when the engine is in the car. Is this a problem? Thanks. cnc

[GeneralDisorder]

My consternation is this: There is no positive lock on the crank pulley. It depends upon friction by the big crank bolt only. That seems odd. There is no taper I can see. And, the direction of rotation is such that any load on the crank pulley, like the alternator, A/C pump, water pump, and brake pump all try to unscrew the crank bolt. I'd expect to see a Woodruff key or something to positively lock the pulley from rotating, and the crank bolt is just there to keep it from moving outward. Is this right? Makes me nervous to turn on the A/C, knowing that I'm adding to the load and possibility that the crank pulley will fall off while driving. With the engine out, I can hit it with a manly-man's rattle-gun, but not when the engine is in the car. Is this a problem? Thanks. cnc

 

It is not a problem. If properly torqued no loctite is needed. I don't even torque them - I just put a ratchet on the bolt and smack it with a small sledge - poor man's impact. That's how I break them loose as well.

 

On some of the early EA82's they did have a round pin that fitted into the front timing belt pulley and locked them down. But it was found they just didn't need it so '87 and up you likely won't see them.

 

GD

[idosubaru]

It is not a problem. If properly torqued no loctite is needed. I don't even torque them - I just put a ratchet on the bolt and smack it with a small sledge - poor man's impact. That's how I break them loose as well.

+1 except i use a 3 foot pipe over my ratchet to tigthen it. lock the engine down so it doesn't give/turn and then tighten. there's no locktite or special trick needed, just need to get it tighter. i put some serious stank on it with a 3 foot pipe, no way they ever come off.

[ettev]

+1 except i use a 3 foot pipe over my ratchet to tigthen it. lock the engine down so it doesn't give/turn and then tighten. there's no locktite or special trick needed, just need to get it tighter. i put some serious stank on it with a 3 foot pipe, no way they ever come off.

 

Yep, I was always told you can't ever make the crank pulley bolt tight enough. Tighten the crap out of them.

 

I had a pulley come loose on a non-Subaru car after a timing belt job I let my inspection mechanic do for me. That pulley was keyed to the front of the crank and he never got it tight enough. Naturally, from being that loose it enlarged the keyway to the point that the pulley was actually banging around on the front of the engine. Had to have the engine pulled and the crank fixed.

 

Tighten the @#&% out of the pulley bolt. I doubt you'll strip it.

[Turbone]

It is possible to get one to tight.

I was taking one off a EG33 and nothing was working. I had a 3ft steel pipe on my breaker bar and was bumping the engine and it would not break loose.

Eventually got a longer pipe and used my 180lbs to get it off :-\

[cnc]

Thanks for all the help, guys. Final parting thought: The engine can only produce so much torque, and the crankshaft is sized to well exceed that torque, but there must be a limit to how much torque can be applied to the crankshaft before you bend it or otherwise mess it up. I'm hoping that strength is well beyond what a knuckle-dragging shadetree wrench such as myself, can produce. Think I'll keep the breaker bar in the car for a few weeks, just to be sure. cnc