7 replies to this topic

[s2ulk]

Hi all, just removed the auxiliary belt and replacing the failed alternator. I notice that all the pulleys rotate freely by hand except for the crankshaft pulley (photo attached). Excuse my mechanical lack of knowledge but I assume the crankshaft pulley is driven by the engine and so it’s correct that it does not rotate by hand? Or am I wrong and it should rotate freely by hand?

[nicklouse]

No photo.

no it should be rotated by the crank. Sounds like the key has failed.

[DeadSquare]

You are correct.

The rotating crank shaft, through the pulley keyed and bolted on to it, drives, by way of a belt, the water pump and the electric generator.

[s2ulk]

No photo.
no it should be rotated by the crank. Sounds like the key has failed.

Sorry photo didn’t attach - now attached. I can’t rotate this pulley by hand - the bigger pulley of the two at the back

Attached Files

•  IMG_2950.jpeg   62.35K   1 downloads

Edited by s2ulk, 08 June 2024 - 08:38 PM.

[s2ulk]

If I have understood Deadsquare’s reply then it is correct that this pulley cannot be rotated by hand

[Midas Mk1]

No photo.
no it should be rotated by the crank. Sounds like the key has failed.

Sorry photo didn’t attach - now attached. I can’t rotate this pulley by hand - the bigger pulley of the two at the back

That’s the crank pulley, to rotate it your fighting the compression of all 4 cylinders. It’ll only rotate with large leverage.

[s2ulk]

Thanks all, very helpful. Will pop the new belt on but looks like it won’t be ready for Beaulieu tomorrow unfortunately….

[Deeppockets]

Ensure to not overtighten the aux drive belt as this can overload the water pump and tension pulley bearings causing early failure. From the manual (belt position 'X' is just below the alternator in line with the alternator lower mounting bolt):

 

Apply a force of 10 kg to the drive belt at

position ’X’ and measure the deflection

between the crankshaft pulley and alternator

pulley.

Deflection must be 6 - 8 mm.

 

Perhaps this should say: "...between the crankshaft pulley and tensioner pulley."

 

 

Also be careful not to overtighten the tensioner pulley retaining nut (25Nm) as from direct experience this stud is easily sheared. 

 

PS it is also worth putting anti-seize grease on the long tension adjusting bolt while you are working in the area - this is very exposed and prone to corrosion. 

Edited by Deeppockets, 10 June 2024 - 10:15 AM.