Peugeot 406 - Crankshaft pulley loose, key broken

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Sat 22 Oct 2016 17:31
Peugeot 406 - Crankshaft pulley loose, key broken - Sailor

2001 HDi

My crankshaft pulley (for the auxilliary belt) was loose. When I finally got the blot out (using the starter to turn the crankshaft with a 22mm sockey and tbar tied against the head and to the subframe), I found:

1. the woodruf key is sheered off.

2. the pulley has massive play - about 1mm !!!!

I'm totally astonished that there is any play! I can't beleive either the pulley or the crankshaft could have worn away that much!

The problem started with a metallic screech, a bit like a loose fan belt but with a frightening metallic edge to it. I ran the engine for a total of a minute or two, over a couple of occasions trying to locate the noise, which went away, and I drove it 300yds round the block! But I didn't feel happy, so today took the Aux belt off, and found the bolt wasn't hoding the pully, which turned freely with play, although the bolt was extremely hard to get undone!

I had replaced the pulkley a couple of years ago, and there was no play then, although the quality of the fit was not perfect. I tightened the bolt (with possibly too much loctite!), and the pulley seemed tight and fine.

I have read 1997 2.1td Crankshaft Pulley - pepperdog which describes bodging a damaged key slot.

The kewyway is only visible in the surface of the timimg belt "sprocket", and not on the crankshaft protruding where the pulley goes. Is this normal?

I have not bought a new pulley, key, and bolt yet. Is it worth a try/ will the key be likely to work, (with or without liquid metal) if I am able to extract the remains of the old one, or is it likely that the crankshaft is damaged? How would I tell if it is? What is its correct diameter?

I can only think the pully must have had some really crap liner that has worn away, in the few minutes the engine has run since the screeching. I can't immagine the crankshaft wearing away!

All the other items on the bely appear OK, and turn freely, steering pump. air-con (itself and its clutch), tensioner, and adjustable pulley. the tensioner feels a tad rough but no hint on any of them of jamming! Many Thanks.

Edited by Sailor on 22/10/2016 at 17:38

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Sat 22 Oct 2016 19:10
Peugeot 406 - Crankshaft pulley loose, key broken - PETER 4768

You probably snapped the keyway undoing the bolt, the bolt would have been seized onto the pulley and by turning one you no doubt turned the other

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Sat 22 Oct 2016 23:47
Peugeot 406 - Crankshaft pulley loose, key broken - Peter.N.

I had that happen on a 406 but suprisingly enough with a new key fitted and the bolt pulled up hard it ran true, just depends how much damage has been done to the mating surfaces.

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Mon 24 Oct 2016 09:09
Peugeot 406 - Crankshaft pulley loose, key broken - Sailor

Do I have to take the timing belt and gear off of the crankshaft to change the woodruf key? It looks like it.

It looks as if most of the key is under that gear. Should it be easy to get a replacement?

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Sun 23 Oct 2016 01:17
Peugeot 406 - Crankshaft pulley loose, key broken - Sailor

You probably snapped the keyway undoing the bolt, the bolt would have been seized onto the pulley and by turning one you no doubt turned the other

No, the pulley was free on the crankshaft before I touched the bolt. The bolt was extremely tight, but not gripping the pulley! Definately not seized to it! Yes mad!

Edited by Sailor on 23/10/2016 at 01:18

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Sun 23 Oct 2016 10:26
Peugeot 406 - Crankshaft pulley loose, key broken - Sailor

Correction - minor typo:

"All the other items on the bely appear OK, and turn freely,"

thats belt: All the other items on the (aux) belt appear OK, and turn freely, ... no sign of anything increasing the torque.

Edited by Sailor on 23/10/2016 at 10:26

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Tue 25 Oct 2016 21:35
Peugeot 406 - Crankshaft pulley loose, key broken - Sailor

Progress Report.

Decided to do timing belt and replace broken key properly.

Bought timing belt kit, and crankshaft pulley (aka damper). This is a different one from the one I'm replacing, and both are different from the original one of pre 2 years ago. However they have the same outside dimensions, and this one fits properly on the crankshaft.

However mistook Newport Wales for Newport IOW, and replacement keys went to Wales :-((

Eventually dismantled everything, but have damaged flange on timing belt crankshaft sprocket/gear/pulley, and its still only 1/2 way off. So I'll probably have to wait for a new one of those too! And with that wait, I'll give up the idea of making my own key to get back o the road... and accept the delay!

So its not too hard to do the timing belt on the 406... once you've found the hidden cover screw down the back of the engine! and realised there are 3 torx screws for the engine mounting.

Thanks to this video: youtu.be/k66VwGX4uGk Excellent.

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