How do I loosen the nut for the pulley on the crank shaft?

[jo_jo]

I need to replace the pulley for the fan-belt on my 1961 Morris Minor 1000, but I'm having problems stopping the crank shaft from moving. I've already tried some crazy methods of which none have worked to date. I would greatly appreciate if someone has any advice to this headache.

[GAS]

Stick the car into top gear and the hand brake on full,choc the rear wheels if you have to...

[bmcecosse]

It needs SHOCK treatment - and have you knocked away the lock tab ?? One method involves a large spanner (or I admit to using Stillsons) fitted on the starter dog - and resting against the nearside chassis member - then you stab the starter motor - making sure the engine can't actually start. Perhaps best to remove the radiator first. If the engine is out the car - then heavy shock blows on the spanner/stillsons - just rely on inertia to oppose these blows - will (eventually) loosen it.

[doobry]

One method involves a large spanner (or I admit to using Stillsons) fitted on the starter dog - and resting against the nearside chassis member - then you stab the starter motor

Have used the starter motor a few times and it's always worked -I managed to get this off with big molegrips but a spanner is much better.
Yes - remove the rad first!
Also remove the fanbelt, and it doesn't matter if the engine starts as the pulley will most likely stay where it is until you lever it off.

The first time I had to do it I used 4th gear and chocked the wheels - was hard even with 36" stillsons!!! Doing it with the starter is a dream in comparison.

[RogerRust]

I use the correct size ring spanner and a few very hard taps with a big hammer. Never fails.

[Axolotl]

It took me six tries using the starter method and a 3/4" Whitworth ring spanner, after having tried hitting it with ever bigger hammers and leaning on very long levers.

Take the radiator out and remove fan belt as described. You'll need the space to get access to pull the pulley off when you finally get the nut undone.

Set something heavy on the floor pan where the end of the spanner will come to rest (to avoid damaging the floor pan or the brake pipe that runs just there), and set the spanner so it is about 6-8" above the floor, then hit the starter as described. You need the movement to get a good heavy blow on the nut.

This job has the potential to damage people and things, so use every precaution, but it probably sounds worse than it is.

[Relfy]

For me it was a combination of a large spanner with scaffolding pole on the end to get it past the water pump, then hammer a little bit, and then I jumped up and down on it with my whole body-weight.

You also really need to put it in gear with someone with their foot hard on the brake.

[RogerRust]

I've just undone the one a an engine I picked up.

I didn't do anything to stop the engine rotating just relied on the compression, flattened the tab washer, fitted the ring spanner and gave it two or three hard smacks with a lump hammer - job done.

As Jim says if that doesn't work get a bigger hammer.

[alex_holden]

As Jim says if that doesn't work get a bigger hammer.

Hey, that's my catchphrase ;)

[Relfy]

I've just undone the one a an engine I picked up.

I didn't do anything to stop the engine rotating just relied on the compression, flattened the tab washer, fitted the ring spanner and gave it two or three hard smacks with a lump hammer - job done.

As Jim says if that doesn't work get a bigger hammer.

If this one is as tight as mine was that wont work - I was just turning the engine over until someone put their foot on the brake, even being in gear.

[alex_holden]

Did you try placing it in fourth gear and chocking the wheels?

[Axolotl]

If this one is as tight as mine was that wont work - I was just turning the engine over until someone put their foot on the brake, even being in gear.

I second that.

I suppose common sense would suggest you try the easier ways first, and work up to the cunning ruses when the easy ones don't work.