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Collection, Preservation and Display of Old Lawn Mowers

Ransomes Certes Mk12 (Help Needed Please)

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Hello,

I’m in the process of dismantling a Ransomes Certes Mk12 and need advice on how to separate the two sides please. Do I need to remove the circlip first (see red arrow) and will I need a special tool to engage in those slots in order remove the assembly. There is an arrow on the side cover showing the direction. (See black arrow)

Thank you.

 

Forums

hortimech Sat, 15/02/2020

Long time since I stripped a Certes, but if I remember correctly, the circlip retains the bearing in the housing, which unscrews. You will need a C spanner to turn it.

wristpin Sat, 15/02/2020

Definitely a job for a C spanner or, depending on the availability of materials and skills, a homemade peg spanner. To preserve the integrity and originality of the machine, resist the temptation to knock it round with a punch.

wristpin Sat, 15/02/2020

Plenty of C spanner’s on eBay, some “adjustable” for the diameter of the component. May  be worth trying the cycle dept of Halfords as push bikes use bearing retaining rings tightened with such tools . Arm your self with the diameter of the retainer before you go shopping .

AUTO CERTES 1 Sat, 15/02/2020

Hi Mower 1

I've just stripped down a mk12 this week too and always use a C spanner. As you turn the bearing housing it draws the bearings off of the hex shaft. Then if you want to get the bearings out of the housing you will probably need bearing puller of some sort. Have you got a decent grass box for it and has it got all the original paint? Should be hammerite silver on the aluminium and brass height adjusting knob and fairly light green everywhere else save the spiral cylinder. 

Mower1 Sun, 16/02/2020

Hello Auto Certes 1 – Thanks for the reply. Did you need to remove the circlip before unscrewing the Landroll Housing.No grass box or any paint on this mower.

I take it back when I said I didn’t have a “C” Spanner I have just found a couple in my shed. I picked up a small box of old spanners some time ago and forgot I had them. I really need to do a complete audit of my shed as I appear to have lost track of what tools I do have :-)

The “C” spanner I have doesn’t quite fit, so not sure if it’s worth spending an hour or so re-shaping the spanner for a custom fit, or buy one? As the Landroll Housing presumably hasn’t been removed since it installation its removal may not be easy.

AUTO CERTES 1 Sun, 16/02/2020

Yes if you have the circlip pliers it takes seconds. A couple of pounds from eBay. Would it be possible for you to upload some pictures of the mk12 with close ups of the land rolls and spiral cylinder please?

 

 

sawfingers Wed, 19/02/2020

From the looks of the burrs on the retaining ring somebody else didn't have a C spanner has gone at it with a hammer and punch. If all else fails give it a good soaking overnight in some diesel or similar and try some sharp but gentle taps with a metal chisel or old screwdriver in the slot

Mower1 Thu, 16/04/2020

Well it’s been a while and thanks for the tips. I managed to modify a “c” spanner that I had which did the job well. Thankfully there is an arrow on the side frame (RHS) showing which way to turn the “Landroll housing”. I couldn’t remove the “Landroll housing” on the left hand side and decided to leave as is. The restoration is not quite completed as I need several parts which I can make, however trying to buy a replacement 16” bottom blade is proving to be problem despite trying several suppliers. Have put this project on hold for the time being and working on a number of other Ajax restorations now.