Broken crankshaft bolt

[cbose]

DOA :

if the pulley slips round (and it WILL do eventually using bearing fit from locktite and just the bolt) it aint just gonna be your pulley and crank thats knackered, youll find peices of valve and piston coming out of your exhaust from the valves hitting the piston as the cam timing goes out too far.

Yup, I don't hold out much hope for the loctite, to be sure. On the other hand will the
failure be so dire? Timing is determined by the timing gear BEHIND the pulley. Surely it
is keyed itself. The pulley timing is only for ignition setup and maybe a sensor or two.
After all, that pulley was moving around some before and wasn't causing a catastrophic
problem. If ignored for a long time (if this was possible) perhaps the gear would spin too
and THAT would be a problem

vrg3:

Just a quick note -- valves and pistons don't collide in our engines, no matter how screwed up the timing gets.

Ok, now I AM confused. I thought that all the subaru engines were interference
configurations, and even worse, you can have valves hitting valves on the quad valve
engines??

At any rate, not to get too far off topic here, newfielady is trying to some help from us
to get her car back on the road, at least for now. The main thing to worry about is
SAFETY of the fix. We don't want any pulleys flying around. Therefore, one step
at a time. First the broken bolt. It shouldn't be too hard using one of the ideas presented
already. If the bolt broke because it bottomed out for some reason then it may be
pretty stuck in there. But it should be drillable, and it is pretty big so a good sized
EZ-out should do the trick. I don't recall that anyone has come up with a fix that
wouldn't involve taking the bolt out! Let us know how that goes and then we can
fall all over each other to suggest the best next step.

Cheers, Chris

[vrg3]

Yeah, Chris, you're right that we got off topic. Just to put your confusion to rest, though, our SOHC Subaru engines are non-interference. Quad-cam engines are valve-valve interference.

You're right that the first step is to get the broken bolt out. A center punch, a hand drill, a good bit for drilling into steel, and a bolt extractor should do it, unless there's siezedness or corrosion (which would be frightening) involved. Good luck with it, newfielady, and let us know how that goes.

[ciper]

DOA: You said "if the pulley slips round (and it WILL do eventually using bearing fit from locktite and just the bolt) it aint just gonna be your pulley and crank thats knackered, youll find peices of valve and piston coming out of your exhaust from the valves hitting the piston as the cam timing goes out too far. "

Which is totally incorrect. If the pulley slips or the belts become completely disconnected the car will still run just fine, just without AC or Power stearing and until the battery runs down.

Now if the timing belt cog was to slip the car would run badly and eventually stall, no piston to valve contact. Its not worth discussing though becuase his problem is with the pulley!

[evolutionmovement]

Just for the record (there's an engine in my kitchen right now), the accessory pulley and the crank timing belt pulley use the same keyway (which looks completely wrecked), so this car shouldn't run.

Steve

[DOA]

I forget you lot have different engines to us lot in the UK but looking at that picture I assumed she meant the timing pulley anyway having not looked at the belt setup on my car before. Still, just dont do it! As I did state, the bolt will undo itself eventually and knowing sods law it will do it at just the wrong time and it aint worth the risk anyway.
Assuming however that there are 2 pulleys on that shaft I can garauntee (yep I really cant spell ) that the cam timing is being pulled all over the place as the timing pulley frets around the crank and that aint good anyway. Get both pulleys off and braze the shaft up and re-file the keyway in, brazing will do the job as long as the key you use is a very good fit and you do a good job on the brazing. Also if your at all in doubt get a dremel type drill and grind the keyway a bit deeper into the steel and make a custom key to fit it properly, thats the only advantage of woodruff keys as they really are crap otherwise.

[ciper]

How does a bad pulley on the front of the crank damage the keyway that is hidden inside the timing belt pulley?

[evolutionmovement]

There's just one woorduff key for them both. Must have just tore it right out of the keyway... The timing gear and crankshaft keyway look wrecked in the picture.

Steve

[cbose]

From the pics I would bet that at least some of the key is left for the timing gear. It
looks like once the pulley was loose, it broke the key a bit inside the timing gear and
the stub end wore a slot in the front of the gear. Once the gear was not being
held snug by the pulley and bolt, it looks like it worried a bit at the keyway and now
is free to move a bit (as evidenced by the slight shift between the right side of the
keyway on the gear, relative to the shaft, also visible in the pic.) The only way to sort
this out is to de-tension the belt to see how much play there is. Should also
slip off the gear and examine the key at the same time.
If ANY rotational play is in the gear, then that will have to be fixed too! But the gear
is so thick that it probably isn't nearly as bad as the pulley keyway, so there may be
an option to to custom fit a new woodruff key to hold the gear secure and to
restore the crank/valve timing.

I still want to see the bolt out before putting any money on the table!

Chris

[newfielady]

Great news!! We got the broken bolt out. Used a right angle drill, drill bit, easy out, and modified "sleeve" to guide the drill bit. Got a piece of steel pipe, with a quarter inch hole in center. Wall thickness of pipe of course wasn't thick enough, so used 1/2 inch masking tape to enlarge. With the sleeve over the drill bit, bit in drill, there was just enough room to get the drill bit into the hole. Had some compressed air in a can, used to clean computer equipment, to blow the hole clean. Got the whole started with the quarter inch bit, but ended up going to a 3/16 bit. That way we didn't have to drill as deep to get the easy out to grab. Had a bit of trouble after we'd gotten the bolt pc to back out about a quarter inch. The crank itself started turning, so stuck the drill bit in backwards into one of the holes in the sprocket. Worked perfectly then, just backed the bolt right out!! Yay!! Now we have to fix keyway.

[vrg3]

Great, glad to hear you got the broken bolt out. How do you plan to fix the keyway?

[cbose]

Great news that you got the bolt out, and very nice job you did of it too. The idea
to make a sleeve to guide the drill is great -- you've got more than enough
chutzpah to complete this job!

Can I suggest a next step? You need to determine if the timing gear behind the
pulley is solid. For that you need to de-tension the timing belt and
try to rotate the gear a bit to see if there is any play. I would suggest going
further: mark the belt and the gear so you get the gear back
on right and SLIP OFF THE GEAR from under the belt. Don't take the belt
off anything else or you'll lose timing! When you put the gear back on, make sure the
marked tooth lines up with the mark on the belt.
It may not be so easy to get the gear off if the
key or keyway got messed up by the pulley, but you need to know what
is going on in there.

If the gear and its portion of the key are still more or less ok, then I think
you are almost there. You only need to find a secure way to mount
the pulley. If not, you need to repair the mounting of the gear first!

Chris

[LegacyT]

More pics of how she got it out!





Mark,

[cbose]

This thread is getting more fun by the minute! Brilliant pictures!
Love the rings!

Newfielady: the rings are cool but a notorious way to lose a finger. If you
short out any live electrical points in the engine bay with your ring, you
can weld the ring and lose your finger. PLEASE make sure the battery ground
is disconnected so you can keep your rings on for future pics

Chris

[DOA]

LOL, sod the rings m8, what about the nails .
If you havent finished the job yet and havent put the new bolt in can I suggest that you beg/buy/borrow a tap to retap the crank, just to make sure that the thread in the crank isnt the reason the original bolt sheared off. Oh and if you dont have a handy drill bit in future to stop the crank from turning try putting the car in top gear (or first I can never remember till actually doing it) before trying to re-torque the bolt up, should stop the engine turning.

[newfielady]

Got it all back together today. I modified the key to fit and used some jb weld on the keyway. Don't know how long it will last but at least the pulley is not out of round or vibrating. I want to thank you all for the help. It really made me feel better to have so many ideas to choose from. Also I normally take my rings off when I work on the car but was just demostrating how I used the drill and steel sleeve. I learned my lesson the hard way about rings. I was tightening the cable on a side post battery when the ring came in contact with the metal body. Needless to say it took a piece out of my ring and I had a nice little gold blister lol. Thanks Again Everyone!

[vrg3]

Sweet!

JB Weld is weird stuff... It's definitely not the "right" way to do most things, and in some cases it fails quickly, but sometimes it works very well for a long time. I think a lot of it has to do with how good a job you do roughening the surfaces, how quickly you get the repair in place, and how rigidly you hold the job while it's curing.

I intentionally use my rings as temporary jumpers when doing electrical or electronic work all the time. :)