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Crank pulley loose

Posted: Mon Sep 13, 2010 2:05 pm
by gatsby989
Morning all,

Yesterday my friend and I did a first real inspection of my new moggy - a 1957 2 door w/ 948cc. She runs, but there was an odd noise coming from the front end. Turns out the crank pulley / harmonic damper was loose. The pulley itself seems ok, but there was some play in how it connected to the crank. Where it fits on the crank, there's a keyway, and the key seems to only fit about 1/4" inside the pulley. That part of the keyway on the pulley is very worn. Is the key pushed too far back on the crank, or is it supposed to be that way? Do you think I could slide the key forward and reinstall the old damper, or do I need a new damper?

Thanks,
TomK

Re: Crank pulley loose

Posted: Mon Sep 13, 2010 2:28 pm
by Alec
Hello Tom,

isn't the key a woodruff key, i.e., the part circular type so cannot be moved backwards or forwards.

If it only engages in a quarter of the pulley depth, something is wrong as the pulley should go completely over the key.
Is your pulley a steel riveted construction, which most Minors are, then I would get a new solid pulley and key to sort your problem out. I think most Minor suppliers now stock the solid pulley.

Alec

Re: Crank pulley loose

Posted: Mon Sep 13, 2010 3:06 pm
by gatsby989
It looks like the pulley is not the solid kind - it appears to be the damper kind with the rubber ring. So it may need replaced anyhow. As for the key, the manual shows that it is supposed to be a semi-circular woodruff key as you state. It just occurred to me that perhaps the key is broken half off? :-?

Re: Crank pulley loose

Posted: Mon Sep 13, 2010 3:16 pm
by mike.perry
The key should fit in the groove parallel with the crank, if it sticks up at one end it may need tapping into position with a hammer

Re: Crank pulley loose

Posted: Mon Sep 20, 2010 9:57 pm
by bmcecosse
Most unusual for you to have the harmonic damper - has the engine been modified in any other way ? It certainly was never fitted as standard to any Minor engine. These dampers are now hard to find - if the bore is still a good fit to the crank - you could just have another key slot cut in the damper hub and use that with a new key of course. More worrying though is that the key slot in the crank may be worn - you should check to see if a new key fits tightly before doing anything with the damper.