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Collection, Preservation and Display of Old Lawn Mowers

Ajax mk4 & mk5

Hi everyone, I have just joined and bought myself two Ajax models mk4 & a mk5 so hopefully I can make one that work out of the two.

I do have a question though if it is ok, 

I would like to know is there a difference between the two models and if so what are they please?.





Clive1997 Thu, 03/05/2018

Hello Brad

Welcome to the forum, good question, answer is, Not a lot!

I have just had a quick look at the parts list for the 4 & 5 and the only difference would appear to be the front wooden rollers, Mk4 has 3 of equal size & Mk 5 has 4, 2 large in the centre & 2 smaller ones on the outer sides, plus a pin & washer between the large & small, the pin going through the roller shaft. The grass box also has a different part number, with the mk4 box having 2 separate embossed panels on the sides with the word Ransomes in the middle.

I have quite a few Ajax's around plus many boxes, will take a closer look next time I see them to see if the differences in the parts list are in fact reality.

Oh the other difference is of course the scraper/name plate!

Hope that helps.




Brad Thu, 03/05/2018

Thanks Clive, I have ordered two small and two large rollers, I only have a grass box with embossed sides but I thought it was from the MK5, and I only have the name plate/scraper on the MK4.

So it looks like I'll have to make a frankenstein mower!!.

I'll see when I dismantle them over the next week or so, then strip or media blast the parts.

The club site has been pretty useful so far. 

Harvey Fri, 04/05/2018

I have one of each.  Apart from the differences already mentioned, the grassboxes are a different shape:  I may have a photo' of each somewhere.  Will post if I find them.



Brad Fri, 04/05/2018

Thanks Harvey.

I dismantled most of one today, it seemed in pretty good condition considering it looks pretty abused, even the cams worked which I was surprised about.

I have encountered one problem though, the alloy gear cover has a hole in the bottom where it has worn away, looks like it has been dragged over stones or something, I thought no problem as I have a spare.......... but no that is damaged in exactly the same place!.

Unless anyone has a solution or knows where I can get one in good condition I thought I would try chemical metal, then sand and paint?.



Clive1997 Fri, 04/05/2018

Hi Brad

I have got several spare ones for breaking, it looks as if you are not too far away from me, drop me an email & will see what we can sort out.

Brad Sat, 05/05/2018

Cheers Clive will do.


I just got a price for sharpening the cylinder and bottom blade, £30 from Ray forster garden machinary in Turners hill just p the road from me, £50 if it is on the mower.

Is that a reasonable price?. Also 2-3 week turn around which I thought is long, so they may be sending it out to someone else.

Harvey Sun, 06/05/2018

This is the MK4 grassbox.  The sides are tapered unlike the MK5 'box which has parallel sides;  Sorry the pictures are not much cop to show it: the only ones I have.



Brad Mon, 07/05/2018

I'll take the better cylinder and bottom blade up there at some point Wristpin cheers.


Thanks Harvey , the one I have has straight side so must be the MK5, I was going to strip it, repaint in Forest green then add the new decal there is only one small dent to try and push out and luckily no holes or too much rust, we'll see because I think it is a bit to thin for blasting.

wristpin Mon, 07/05/2018


 I think it is a bit to thin for blasting.

Soda blasting is fairly gentle.

Brad Fri, 11/05/2018

Well up date, it is coming along slowly.

New Oak rollers turned up from Michael Floody found him on this site, they look good.

Nearly finished dismantling parts to clean, like the bearings.

Going to chuck all the screws, springs etc into a milk carton of Coke to clean them up.

My only set back was the the roller and bottom blade, I took them to Horace fuller in turners hill, by email they said £35 if I bring the parts in, £50 if it is the whole mower, so I bring the blades and the chap on the counter still says £50, I was not best pleased, so if it's £50 I will find somewhere else on principle but I left it with them and they said they would call me once the other chap is back in the shop.

We will see, but I wasn't happy!.