Ransome Ajax MK4 - Roller drive cog removal

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Antbr123
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Ransome Ajax MK4 - Roller drive cog removal

All,

Apologies to older club members if this help request appears to be a repetition of early requests - but I have searched the forum and found that this problem which was raised in 2015, does not have a detailed answer - and I tried previous solution suggestions. 

But how do I remove this ruddy cog?  I have tried hand pulling it, wiggling it, prising it up, unscrewing it.  No joy. Do I need to get brutal? Total novice on Ransomes- this is my first attempt. I have reviewed the pdfs on the site on the Manuals and looked at the exploded drawings.  There seems to be a pin behind the cog euphemistically called a "grooved pin - Landroll spindle" in the MK5 manual - but no description in the MK4 manual. Could this be stopping it - if so what do people recommend as a step by step procedure?  Any special tools required?

All help gratefully received.

 

NM
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Hi, the ‘ruddy’ cog is a

Hi, the ‘ruddy’ cog is a interference fit on the spindle and should lever off after the retaining nut has been removed, LH thread I think. Place lever as close to centre as poss. to prevent distorting driving cog. The pin  sits in the back of the gear through the spindle and doesn’t need to be removed until the gear has been removed.

Also you could try some heat.

Here’s a pic of slot for pin on rear and inside of cog

       

Antbr123
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NM - that is most helpful. 

NM - that is most helpful.  Thank you! Your pictures certainly help to understand what is happening behind the drive cog.

The terminology "ruddy" cog was a sign of unprofessional frustration after 2 hours of efforts to remove it therefore I owe apologies to anyone who might have taken offense at this as a sleight on our mutual interests.

I will give your suggestions a go and hope to communicate success in the near future.

 

Antbr123 (Tony)
Consider grass in terms of how you would like to be treated yourself - and you won't go wrong!

hillsider
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It may help you to break the

It may help you to break the gear loose if you replace the nut onto the threaded shaft but only screw it down to a full nut to protect the exposed thread. Then apply outward pressure as has been suggested then tap the end of the roller shaft inwards, this will hopefully then move the gear up the shaft until it reaches the nut. 

You may find that the alloy hub of the gear has been crushed in by over tightening the retaining nut causing it to grip the threaded shaft.

 

Antbr123
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Hillsider, many thanks for

Hillsider, many thanks for the advise.

I can now report that the "interference fit" shown by the cog was not as great as my interference!  I attach some pics showing the state of the bore which showed it self to be grooved suggesting previous interference!

Positioning the threaded screw hole in the cog at 9 o'clock and driving a tapered flat  cold chisel in at 3'o'clock and gradually winding in a threaded bolt through the hole in the cog so that it pushed against the side casing proved too much for it.  I was getting nervous at the strain I was putting the cog under, but its come off and is not warped which was my biggest concern.  Threads on the roller axle have also been retained - so all in all a success - if only 5 hrs time consumed and a learning curve climbed. Further more previous pictures provided showed the positioning of the pin which is at 90 degrees to the threaded hole in the cog. That helped a lot with identifying where to put pressure so that I was not pushing on the back of the grooved pin.

Grateful thanks to all for the advise and support!

Antbr123 (Tony)
Consider grass in terms of how you would like to be treated yourself - and you won't go wrong!

NM
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Hi Tony, glad you’ve managed

Hi Tony, glad you’ve managed to remove offending part. To be honest I thought your use of the word ‘ruddy’ was an understatement and am sure I’d have used something a lot worse.

Antbr123
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Thank you NM!.  The air in

Thank you NM!.  The air in the garage was extremely blue at the time... and not from my cigarette smoke.  My wife and dog kept well away from me! 

Upon reflection, my former apology was an afterthought as you do have to be so careful on forums in your use of terminology lest offending more sensitive souls, even if in doing so it goes against the grain of your natural character instincts. My expletives were nearly as strong as the paint stripper I had working elsewhere in the garage and I am sure the dog ran off up the garden with dietary problems!

Now - does any of  you have experience of removing the bearing housing off the cutters.  Again drawings suggest they should be "interference fit" and to be honest they seem fine, so I am tempted not to remove at all. They seem to be self aligning bearings as there is plenty of play in them from the cutter angles I can achieve by holding them vertically in a vice.  But I may need to remove on a MK3 I have waiting in the wings...

Antbr123 (Tony)
Consider grass in terms of how you would like to be treated yourself - and you won't go wrong!

NM
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Hi Tony, the bearings are RL5

Hi Tony, the bearings are RL5 I think, they’re listed in the parts list for Ajax on the site.

The best way I found to remove bearings is with axle stands. Basically two lengths of tube with angle iron welded in the top. The width of each stand will spread the load over the ends of two of the knives and they just popped off.

Nick

wristpin
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The best way I found to

The best way I found to remove bearings is with axle stands

     ?????

Not sure where axle stands come into it but I like your design of "pry bars"..  A lot easier than trying to balance two big tyre levers on the ends of two opposite blades to avoid distorting the cylinder flanges/ webs.

NM
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Hi Wristpin, what I meant was

Hi Wristpin, what I meant was the adjustable centre part of the axle stand, I didn’t try and use the whole thing, honest.

Antbr123
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NM/Wristpin,

NM/Wristpin,

I am glad that I was offline for a couple of days while this thread developed, as I ended up earlier with a vision of NM sitting astride the cylinder blades resting on 2 axle stands, armed with 2 pieces of scaffold tube in danger of doing himself some severe damage!!......for some reason the Tchaikovsky's Nutcracker suite has just come on the radio...

I like the idea of the scaffold tubes - perhaps NM you could "simulate" their use in a picture so I can visualise some more?

Antbr123 (Tony)
Consider grass in terms of how you would like to be treated yourself - and you won't go wrong!

NM
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Hi Tony,

Hi Tony,

I’m sure there are more ‘simulating’ pictures on ‘t’ internet than me removing bearings from a lawnmower.

Nick