Crank shaft pulley and gear replacement

8 years 11 months ago #34516 by Luckymarine
Symptoms in order.

Battery light flickering
Dials going crazy (as if they had a rave going on back there)
Power steering dying

At one point, the moment the crankshaft pulley was worn down enough to allow full rotation the car sounded like a tank, trust me I have been stood next to plenty of them, in a way I was rather proud that my TF would give a Challenger a run for its money on the sound front! After this happened there was a rapid deterioration through the stages as I was then just on residual battery power.

Parked up on the drive and found the crankshaft pulley was wobbling all over the place and therefore the alternator belt was slack and thus not charging the battery enough. God knows how I managed to get to my final destination but sometimes we're lucky like that!

Anyway a quick search on the internet got me a crankshaft pulley and I thought ahead and got them to send me a crankshaft pulley gear too as they are "keyed" and fit together.

Good job I thought ahead!

Anyway a few photos of what was on / came off.

Now Im brave/foolish enough to take a few short cuts with my car. But when it all goes wrong it usually means more work to do, thing is when I did the work I was stuck in the middle of Tamworth with the tools I leave in the boot. If I had been at home in the garage then it would all have been striped an calibrated/times properly.
Disclaimer done.

First thing to do is take the back wheel on the cam belt side off, lower the car back down so the opposite wheel is back on the ground but still supported, engage a gear and get someone to depress the brakes. I say get someone else to depress the brakes and not just put the handbrake on because the handbrake by comparison is weak, it only acts on 2 wheels and is only designed to keep a vehicle stationary, whereas the footbrake acts on all 4 wheels and is designed to slow the vehicle down from speed as soon as possible. With the footbrake being hydraulic there is much more clamping force available, the handbreak is just a ratchet and cable affair and you'd snap the cable before you even got close to the same force as the footbrake.

You should be greeted by a sight similar to this...

It takes only slightly less effort to get this bolt off than it does to move the Moon, you will need at least a half inch socket set, a couple of extensions and a pole of some sort to get the leverage required to undo it. You might need to shed blood too as was the case with mine but I find that most of the jobs I do on mine require some sort of blood in exchange for it to be fixed.

After taking the bolt out I tried to pull the pulley into "centre", was having none of it and a previous owner had probably taken it to a garage and they had just adjusted the alternator to put more tension on the belt.

Took the belt off and investigated what range of movement the crankshaft pulley had. Bare in mind that this is a keyed item and they are meant to slot together and hold fast....

And the new Crank shaft pulley just to give an idea of how much metal has been machined away!

Took the pulley off all together and turned it over, the differences between the old worn one and the new one are plain to see. The pulley is usually held in place by the clamping force of the bolt and prevented from turning by the lug so it pretty much just falls off once the bolt is removed.

Obviously the one on the left is what you should see, the one one the right has had lots of metal eaten away and is useless, unless you need a paperweight.





You get the picture. Anyway looking back at the engine you should see a sight similar to this...

You should then be able to take the cam belt cover off.

(Forgot to take the pictures whilst taking the old Crankshaft gear off so the last 2 pictures are of it all going back together but in reverse, but you get the idea. For the eagle eyed amongst you its why the crankshaft gear looks undamaged.)

Now for the Crankshaft gear removal, if I had been at home in my comfy warm garage, with cups of tea, the radio and as many biscuits as I could get through then I would have properly timed the engine and whipped the cam belt off. However.... middle of Tamworth, feels like its going to rain at any minute and no biscuits prompted me to employ some rather dodgy mechanical engineering practices that Im not proud of but it got a job done quicker, not better, just quicker.

The Crankshaft gear is splined to the shaft so there is only one way it will fit on. To that end I clamped the cam belt to every pully I could find and then gradually slid the gear off the shaft. It may need a bit of a persuasion with a screw driver to get it started but it should slide off pretty easily once its going.

You should be left looking at this, note the D shape of the shaft.

And you should have this in your hand..

Note the bluing of the steel, that only happens at high temperature and baring in mind the cam belt goes round this I think I had a lucky escape.

Again you can see the effects of temperature and also the fact that there is no lug where the lug is ment to be, all 3mm of it has been worn away allowing the Crankshaft pulley to turn freely.

Putting everything back together is the opposite of removal, although to get the Crankshaft gear to sit right I pushed it on as far as it would go and then used the old gear and bolt to force it home.

I obviously made sure the teeth of the new gear went in exactly the same place on the cam belt as the old one and everything went back together fine.

Did need to loosen the Alternator off a little so I could lever it away and get some tension on the Alternator belt, was a right fiddle but get there in the end.

Vehicle fixed and had no other issues with the Alternator or belt since, although I have done a head gasket since then and replaced the cam belt in the comfort of my own garage, with biscuits....
The following user(s) said Thank You: psymon, David Aiketgate, bryan young, Leigh Ping

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8 years 11 months ago #34518 by David Aiketgate
Nice one, Darren! :thumbsup:

I've seen this problem quite a few times on these engines. :yesnod:


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8 years 11 months ago #34520 by Luckymarine
Had the pictures in my photo bucket, saw there wasn't a how to so thought I'd give something back to the forum.

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8 years 11 months ago #34532 by bryan young
David, could you add this to the "How to's" Please :yesnod: :thumbsup:

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8 years 10 months ago #34543 by David Aiketgate

bryan young wrote: David, could you add this to the "How to's" Please :yesnod: :thumbsup:

Absolutely! :yesnod:

The following user(s) said Thank You: bryan young

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8 years 10 months ago #34561 by Leigh Ping

Luckymarine wrote: Had the pictures in my photo bucket, saw there wasn't a how to so thought I'd give something back to the forum.

Great job. You've made it. :) Check it out in the 'how to' section.

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3 years 6 months ago #177564 by red rose
I like this offering. I've a vvc aircon model if that makes any diff . What is of concern is the 'clamping the belt' bit. Any release in tension in the belt will be taken up by the tensioner requiring removal ,this I take is not the purpose of the clamping. Have you or any member of pics showing how this can be achieved

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3 years 6 months ago - 3 years 6 months ago #177573 by mgtfbluestreak
The rubber insert is is a crank dampener has you all know.....ive seen damage to bearing shells/bearing caps due to running engines after these dampers have failed.....although the damper on the right is is showing some bad cracking...:dry:

£34.99 for a new damper has seen on ebay below:hgf:

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