Broken Crank Pulley and Damaged Crank

[RichP]

Hi all

Further developments from this thread:

http://www.hiluxsurf.co.uk/forums/sh...ad.php?t=62809

Our Hilux Surf suddenly developed a huge oil leak from behind the crank pulley . So, I bought a new seal and set about changing it. However, as is so often the case, things are not so straight forward.

The crank pulley seems to be a taper fit on the end of the crank, aligned by a key. The bolt I believe should by ultra-tight (not sure how tight). A puller should then be needed to remove the pulley. I found the bolt relatively lose, and the pulley was also not hard to get off.

So, as you can see from the pics it's all gone a bit wrong. I don't know if the pulley is broken because the bolt was not done up tight enough at some point during a past "repair", or whether the bolt was loose because the pulley broke for some reason.

In addition, the key is a very lose fit in the keyway, I think more lose than just caused by wear / pulley movement. However I understand the key is for alignment purposes and shouldn't be doing any work once the bolt is tight. The taper fit should do the work to hold the pulley in place. So, perhaps this doesn't matter too much?

I can buy a new key & new pulley, fit the new seal and put it all back together again, but I have a couple of questions first:

- anyone know why this might have happened? I'd like to prevent a re-occurance. Is this a known problem?

- I'm a bit worried about the damage to the crank where the pulley has been wobbling about - is this likely to stop the new pulley seating properly and therefore cause it to work lose again? I've no plans to rebuild the engine and replace the crank. Should I add some locktite-type stuff when refitting the pulley to try and keep it locked on tight?

Lastly, I couldn't release the alternator belt because, despite removing the clamp bolt on the adjuster, the alternator still won't move down. The bolt through the engine bracket must be very tight to hold it so solidly, and I can't release it as someone in the past has rounded all the corners off the head. Any tips?

Many thanks
Rich

[Justbrad]

This happens on the 2.4's, I've seen the key way alot worse than that on a crank.

The woodruff key should be tight in the key way and threadlock should be used on the bolt when putting it back in. I wouldn't trust just the taper to hold the crank pulley.

[RichP]

Do you think I can fit a new woodruff key and pulley to the crank and get away with it though?

[TonyN]

The pulley isn't tapered, its held on by the bolt, its done up to 270ft/lb, the key dosn't have to be uber tight, mostly you can get them out by hand.

Its come loose, thats all thats happened, theres nothing to watch or do differently, its just wasn't done up properly, with drastic results! lol

The crank end dosn't look toooo bad, clean it up and smooth out the burrs on the key way.

Try a new pulley on it and check it dosn't wobble.

I'd fit the new key with some chemical metal round it (as little as poss, don't glue the pulley on with it, or push excess into the timing cover), then install the new pulley and let it set, free the pulley, then torque the bolt up properly with some lock tight on it.

[Justbrad]

The pulley isn't tapered, its held on by the bolt, its done up to 270ft/lb, the key dosn't have to be uber tight, mostly you can get them out by hand.

Its come loose, thats all thats happened, theres nothing to watch or do differently, its just wasn't done up properly, with drastic results! lol

The crank end dosn't look toooo bad, clean it up and smooth out the burrs on the key way.

Try a new pulley on it and check it dosn't wobble.

I'd fit the new key with some chemical metal round it (as little as poss, don't glue the pulley on with it, or push excess into the timing cover), then install the new pulley and let it set, free the pulley, then torque the bolt up properly with some lock tight on it.

I totaly agree with Tony, I wasn't too sure about the crank bring tapered, I knew the 2.4's weren't but not the 3.0.

[RichP]

Thanks for the information and tips - I'll give it a shot - fingers crossed!

[OllieNZ]

I'd fit the new key with some chemical metal round it (as little as poss, don't glue the pulley on with it, or push excess into the timing cover), then install the new pulley and let it set, free the pulley, then torque the bolt up properly with some lock tight on it.

Try Metalset A4 if you can find some, put silicone spray on the shaft and pulley first and the metalset will fill the hole tightly and not stick it together, dont get any spray on the threads.

Ollie