Crankshaft damper

MikeT · Post by **MikeT** » 06 Mar 2008, 11:39

Since replacing the crankshaft pulley & damper a worying noise developed and on inspection Jim found the crank bolt wasn't fully tight. I bought a new bolt and it's nice and tight now but the noise is getting worse, particularly on deceleration and idle. I keep checking it, expecting to see something more obvious and today noticed a distinct offecentre wobble from the damper, rotating at idle.

Does anyone know if this wobble is indicative of something major (like crankshaft twisted) or something minor like the pulley not properly seated?

Post by **CitroJim** » 06 Mar 2008, 12:13

Hi Mike,

That does not sound good at all

Did you pull the pulley off when you replaced the bolt? It is quite OK to do after slipping off the aux belt.

My feeling is that the keyway has worn further and the pulley is fretting on the crank tail to the detriment of both.

It is clearly getting worse and it seems it has got significantly worse very rapidly.

Personally, I feel it is on course to self-destruct and sooner or later either the pulley will break up or the crank tail will snap.

If I were you, I'd not drive it any distance nor at any speed until you know what the problem is. You need to slip the pulley off and see what is going on.

MikeT · Post by **MikeT** » 06 Mar 2008, 14:05

I didn't remove the damper pulley, worried the tension would make it impossible to replace or cause it to not align properly, which is what seems to have occured anyway

What you say about the keyway seems logical. I'd be happier to know that's the case than, say a twisted crank.

Can I remove the damper and inspect the keyway without resorting to full belt removal procedures? Would it go back together again so I could drive it (delicately) to a local workshop if need be?

Post by **CitroJim** » 06 Mar 2008, 14:12

MikeT wrote:Can I remove the damper and inspect the keyway without resorting to full belt removal procedures? Would it go back together again so I could drive it (delicately) to a local workshop if need be?

Yes you can Mike, just slip off the Auxillary Belt and pull the pulley off. You won't upset the cambelt...

MikeT · Post by **MikeT** » 06 Mar 2008, 14:16

Sounds easy but that belt has some serious ridges that key into the pulley valleys, are you sure it will just "slip" off?

Post by **CitroJim** » 06 Mar 2008, 14:36

Sorry Mike, me obversimplyfying again

You can't just slip it off, you need to release the eccentric tensioner first (6mm Allen Key). That'll release enough tension out of the belt to pull it off the crank pulley.

You'll need a 1/4" square drive as well as a 6mm Allen key to re-adjust the tensioner after you've finished; the aux belt needs to be well tensioned if it is not to thrash about..

MikeT · Post by **MikeT** » 06 Mar 2008, 15:14

Does any of that require the removal of the cambelt cover, you know how I feel about my (unrevised) cambelt cover

Post by **CitroJim** » 06 Mar 2008, 15:20

MikeT wrote:Does any of that require the removal of the cambelt cover

No Mike, the whole of the Aux belt run is uncovered

MikeT · Post by **MikeT** » 06 Mar 2008, 15:25

$\:D/$ A job I can do! $\:D/$

MikeT · Post by **MikeT** » 07 Mar 2008, 11:25

Update

Once I released the auxillary belt tension the problem was most obvious. The damper was flapping around loose as you like. The pulley bolt, however, was very tight all the way out (must be a lot of sealant dust in there or something). Jim's guess the cambelt pulley failed again was, fortunately, incorrect. Not so fortunate for the damper though.....

The broken piece was wedged in the cambelt pulley recess and the woodruff key just dropped out. Now I have to figure out how to get a spare from the breakers before the end of the day!

Post by **RichardW** » 07 Mar 2008, 12:09

I reckon you need a new woodruff key in there too otherwise the timing is going to flop about possibly. Trouble is you might need to back the cambelt tension off to get it in

Post by **CitroJim** » 07 Mar 2008, 12:38

Most importantly, what does the crank tail keyway look like Mike?

MikeT · Post by **MikeT** » 07 Mar 2008, 12:39

Agreed on woodruff key, it's well hammered. As long as I don't have to remove the cambelt covers I'm willing to give it a go releasing the cambelt tension - is that possible?. I don't have much choice really either way. Of all the weekends, for this one I need a car

Poole breakers don't have one but New Forest Auto's reckon I'm in with a good chance as they got both Xantia's and Pugs. Not sure which model pug I should look to (109?) I'll take the part with me to be sure.

MikeT · Post by **MikeT** » 07 Mar 2008, 12:42

citrojim wrote:

Most importantly, what does the crank tail keyway look like Mike?

It's not easy to see without removing the cambelt pulley Jim but I didn't notice anything amiss.

MikeT · Post by **MikeT** » 07 Mar 2008, 16:42

Went to breakers but the only damper I found (on a Pug) was seized on. gave some hefty wacks with a club hammer and a tyre lever behind it but it wouldn't come off. The yard workers tried to assist but soon gave up