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Front Pulley & Harmonic Damper


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Quoted from garyf
Can anyone confirm if the Front Pulley and Damper assembly on the 6 Cylinder Triumph Engines are bonded together somehow?

There should be a bonded rubber ring between the metal ring that holds the fan belt, and the inner fitting that goes on the crankshaft - its not unusual for the older ones to loose the bond, allowing the outer ring to slip - which also makes the timing marks off.

There's an american company (forget the name) that will rebond them, or Moss sells repros


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I suppose when they fail the pulley comes away from the damper?

I've had a strange noise from the front of my TR and was told to check this, the two parts are still joined securely on my car, although the Front pulley bolt was loose!

I'm hoping that when I reassemble and tighten the Bolt to the Correct torque setting it will be quiet again, hopefully.

I've attached a Picture, you can see the rubber bonding on the front of the Fan belt Pulley, presumably this goes all the way through the Pulley and into the Damper?  

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Yes, it does, but originally the rubber was flush with the surface of the pulley.
Yours has perished considerably.

Best way now is to assemble the pulley to the engine, set the crank to TDC by means of a piston stop (QV elsewhere here) and see if the pulley marker also aligns with TDC.
If it doesn't then the pulley is scrap, as once moved it will move again.

In the day, Kastner would drill a hole down into the deep of the pulley V, right into the hub.
The if the damper moved, the hole would not be as deep as it first was.
But that would only work for a new one.

I'd be most interested to know the result of your first TDC check, as despite the above, KK's caution and the age of these parts, I've never seen one that had shifted!    Even looking like yours.


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It looks like I need to establish TDC and see it aligns with the TDC Mark on the Pulley?

When I removed it I couldn't feel any discernible movement between the two parts, but like you say the rubber does looks perished

You can get new Repro ones, but with my experience of Reproduction parts I'm not willing to take the risk.

I do know someone that can sell me a secondhand one if it is scrap, but I'll need to check this one too.

Whats the easiet way of checking if the TDC mark is actually at TDC?  

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Gary, there's a chap here in Oz who re-rubbers pulleys. He did mine and it looks good. There was a conversation on Sideways about getting more done, but he doesn't do them very often and only in batches of six. The conversation stopped at that point because we didn't have six interested customers. If you have five friends...

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The trouble is I live in England

The rubber looks very perished where you can see it, although the pulley and damper seem firmly connected?

I suppose I could compare it with another known good one and see if the TDC Mark and slot for the the Woodruff key are in the same positions.

If the rubber has failed would it cause a noise at tickover?  

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Is you engine in pieces?  In the pic, your pulley is very oily!

If not, as I said, reassemble.
Set No.1 to TDC.  A piston stop in the spark plug hole; TDC is halfway between both stopped positions OR just pop a screwdriver in and estimate TDC by eye or a dial gauge on the end of the screwdriver.  That'll be good enough for this purpose.

No, it'll be silent.  
What drive you to take the pulley off?


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Engine is in the Car, the Pulley isn't oily I've just re-pained it with Black Smootrite

The reason for removing was on the advice of Dave the Guy who looked at my PI Problems on Good Friday, he noticed the Fan was wobbly and he could hear a funny noise from the front of the engine on Tick over

The Fan was loose because the PO had not used the proper locking tabs on the bolts when re-assembling!

I was worried about getting the Crank Pulley Nut undone as I've heard they can be a swine to undo, but I more or less undid it with my hand

It wasn't tightened to the 90-100 Lbs/ft specified in the Workshop Manual that's for sure?

Fortunately it doesn't seem to have damaged the Woodruff key and the Pulley is a snug fit on the Crank still.

I will do what you suggest regarding checking TDC, if the damper/pulley hasn't moved I will reassemble and torque to the 95 Lbs/ft and then fit the proper locking Tabs when I re-fit the Fan.

Hopefully it will be quiet then?

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I think you have diagnosed the noise (loose fan) and are worrying unnecessarily!

But Hammerite?!?!
  That dies so thick, how are you going to read the timing marks?   TDC may be visible, just, but the fine before and after graduations?  Not a chance.

This how to paint a pulley.
Thin coat of black matt.
Scrape off paint in TDC and graduation grooves.
Spray with white primer.
Scrape off white paint on surface, leaving it in grooves.
Spray with clear lacquer.

This is what it will look like - I had only scraped back the before graduations when I took the pic.


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Excellent Idea with the Timing Marks, Originally I marked the 11 Degree's BTDC mark relevant for the TR5 with some of the Mrs's Nail Varnish!

I was going to do this again, but will use your method.

thanks for all the Advice .  

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Fully agree with John about Smoothrite/Hammerite).  Dries hard and chips easily and a pain to do extra coats.  I use Toughcote which is more durable and easier to work with but only available as a spray so have to do the 'spray in the lid trick'.  This is expensive but worth it because I consider it a better product and buy on ebay in sets of six cans (or more depending upon how the finances are).

Painting the timing marks.  I personaly paint pulley black and use Tippex roughly painting the indentations then wiping off before it dries.  Light rub over with fine wet and dry to take off any white cloudyness if it is there.  Seems to work OK for me.


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I've not had chance to replace the pulley and check TDC yet, been laid low with a bout of Man Flu

However I did get chance to compare my pulley/damper with a known good one thanks to my mate Steve who's got a spare one, the key way and TDC Slot where in exactly the same location as Steve's spare pulley

Steve told me he's seen them perished like mine before, his spare one was starting to perish but not as bad as mine I suppose after 40 odd years of Oil, Salt, Heat & Cold it will start to degrade the rubber?

He's cut off the perished rubber flush with the pulley with a Stanley knife blade and the rubber seems fine underneath.

I've stripped off the paint adjacent to the TDC mark but I have no timing marks on the pulley at all, weird?

According to the Haynes manual I have 10 degrees BTDC Is 14.68mm from Tdc, the timing on the 5 is supposed to be 11 degrees Btdc, so I have measured 16mm and cut a small slot with a hacksaw at this position, also made a punch mark in the middle of the slot.

I can now re-paint in black and put some White Paint/Tippex in the slot.

Will double check TDC when I refit just to be sure. I'm waiting for a new Fan fitting kit to come from Canleys and will re-fit it all on Saturday if I feel better.

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Did a bit more this afternoon before the Snow Came!!

Changed both Steering rack Gaitors and started to refit the Pulley and Damper

A few Photo's?

The nearside Gaiter was a pain to fit till I decided to Soften it up in some Hot water for ten minutes

Managed to squeeze it on then.

Off to Newark Autojumble tomorrow, hopefully I'll be back in time to finish off the Fan & Rad?

Need it ready for Drive it day!

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