Help needed, can’t release cast iron wheel

[MacolmParticipant @macolm]

I note the cast iron wheel appears to have a groove at the front, probably for a dedicated puller. The aluminium may just have the same feature. This feature was sometimes used to allow removal of tight fitting car engine and suspension parts.

To use it, you would need to make up a split puller which is turned up to fit the groove dimensions, then sawn in two axially so that it can actually be fitted over. You also need a close fitting sleeve to go over to retain it. It is usual to make the split sleeve also have the detail repeated to fit a threaded bush for the extraction bolt.

A puller like this is able to apply much more force that the universal type, and with little risk of causing damage, but is quite a lot of work to make.

[noel shelleyParticipant @noelshelley55608]

Howard has it ! the coef of alli will cause it to let go when heated. Load it, heat it, and off it should come ! Noel.

[HopperParticipant @hopper]

Dont even try to hook a claw puller like that onto the outer rim of an ali pulley. It will snap chunks out of it for sure.

Heat the ali pulley up good and hot, about 200 degrees C. You can tell 100 C by spitting on it and the spit sizzles and dances and evaporates. At 200 C it just sort of disappears on impact.

Most — but not all — ali pulleys fit on a straight shaft with a key and a grubscrew down in the bottom of one of the V grooves in the pulley. Make sure the grubscrew is removed and squirt some WD40 down there first.

Once its hot you should be able to lever the pulley off from behind the hub, gently. Of if you have a proper steel split bearing puller that can fit behind the pulley and put puller force on the hub, use that. But usually enough heat will work miracles with ali.

Edited By Hopper on 07/03/2021 05:15:47

[Ady1Participant @ady1]

I would check for a key or pin or grubscrew first

Then rig up a small hydraulic jack as a puller,3-4 tonne

For what they can do they are amazingly cheap and simple, screw stuff doesn't compare

Edited By Ady1 on 07/03/2021 06:15:54

[Nicholas FarrParticipant @nicholasfarr14254]

Posted by john halfpenny on 06/03/2021 16:29:54:

Not easy because heat will also tend to expand and lengthen the spokes, which will tend to tighten the hub on the shaft. Quick heat on the hub, a bigger puller with more arms, and a big hammer.

Edited By john halfpenny on 06/03/2021 16:31:13

Hi, not so, when heated the bore will always increase in diameter no mater what external forces are on it. Things will expand in all directions when heated and if one direction is restrained from expanding, then the expansion will be increased in another direction, Think of the bar experiment in a tightened up vice when heated red hot, the bar can't expand in it's length, but of course when it cools down, it will just drop out, without anyone opening the vice, this is because the expansion is pushed into the diameter, but of cause, contraction also decreases in all directions and so the length of the bar shortens and thus just drops out of the vice. So in the case of the spokes, with the forces of expansion and because of the cold outside restraint, they will increase in their diameter slightly along with the length of the hub. Don't forget, there is also an elastic stage in both tension and compression and cast iron is pretty good at accommodating compression. In all my working life, and the number of pullies I've had to heat up, some with spokes, I've never experienced a bore being nipped inwards when being heated no matter how much heat conducts into the spokes or sold part.

Regards Nick.

[Nigel McBurney 1Participant @nigelmcburney1]

I have restored and worked on many stationary engines ,with flywheels from a foot to 4 1/2 ft in dia,the most difficult are those with well rusted jib head keys,the key causes more problems than the flywheel.I had a customer bring me a 5hp lister CS diesel with spoked fly wheels 30 inches dia.keys came out ok but the flywheels were a tight fit on the shaft .I use the 15 ton ram removed from my press and with a mome made puller,a split steel disc behind the hub,pumped up ram to 15 tons and nothing ,then my wife came to see how I was getting on,she suggested giving the ram a few more pumps until the gauge was into to the red,then at nearly 20 tons there was an almighty bang and the wheel came free. I suspect that there may have been a problem with the flywheels coming loose in service and thewheel was made a tight fit as I had seen one of these engines shake a key loose when running.As it alwys happens a visitor came round and saw the Lister with it flywheel nearl removed, he had served his time at Listers and he told me that one way of shocking a flywheel free was to get a hydraulic puller really tight then hit the flywheel hub with a really big hammer with blows 90 degrees to the crankshaft axis. He agreed with me that hydraulic pullers should not be hit with a hammer only hit screw type pullers, plus I do not believe in heating spoked flywheel hubs,any expansion on the hub puts an outward force on the spokes and so puts a stress on the rim.Taper fits can get really tight ,an easy check to see if the fit is tapered is measure the shaft diameter at each end of the hub,then get an oversized mechanical puller which does not deform or bend and really hit the end of the puller,taper fits really do need a violent shock.

[pgrbffParticipant @pgrbff]

Posted by Hopper on 07/03/2021 04:48:43:

Dont even try to hook a claw puller like that onto the outer rim of an ali pulley. It will snap chunks out of it for sure.

Heat the ali pulley up good and hot, about 200 degrees C. You can tell 100 C by spitting on it and the spit sizzles and dances and evaporates. At 200 C it just sort of disappears on impact.

Most — but not all — ali pulleys fit on a straight shaft with a key and a grubscrew down in the bottom of one of the V grooves in the pulley. Make sure the grubscrew is removed and squirt some WD40 down there first.

Once its hot you should be able to lever the pulley off from behind the hub, gently. Of if you have a proper steel split bearing puller that can fit behind the pulley and put puller force on the hub, use that. But usually enough heat will work miracles with ali.

Edited By Hopper on 07/03/2021 05:15:47

Too late unfortunately. You are a 100% correct, took a chunk out of it with virtualy no pressure at all. 
I cant measure the shaft at the back of the pulley but I cant see a key or screw so I suspect it is going to be another tapered shaft.

Edited By pgrbff on 07/03/2021 09:42:37

Edited By pgrbff on 07/03/2021 09:44:14

[pgrbffParticipant @pgrbff]

Aluminium pulley much easier, not a tapered shaft but no key or screw.

Heated up to less than 100C and tapped off gently. Shame I had to damage it.

Thank you all for your suggestions.

[Phil WhitleyParticipant @philwhitley94135]

Try cycles of heating and cooling, I had to remove a cast 5 belt flwheel from a 22 cu/f/m compressor which had been on there since the late fifties, and a very tight extractor, plus lots of heating and cooling, and ample hammering eventually got it free! They can be very stubborn. See if you can get a large plumbers type blowlamp with a seperate bottle, or a weed burner, or even a parrafin blowlamp, A mapp gas torch will heat it too slowly, as all above have said. I put the blowlamp in a clamp, and left it on the hub for about 30 minutes, then let it cool naturally, and reheat. Dont be tempted to cool it with water etc as this could crack the pulley boss!

Phil

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