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Collection, Preservation and Display of Old Lawn Mowers

Dennis Z Type Rear Roller

Hello everyone,

I have searched this site and have found several references to The Dennis Z Type rear roller including the Dennis operating manual, and the editions of GrassBox No.s 82 & 83 which both contain excellent articles by Geoffrey Brooks. The one thing I do not understand is the instruction on lubricating the rear rollers.

The ops manual says "driving rollers should be frequently lubricated by the nipples on each end and also on non oil bath types through the 3 holes (closed by setscrews) in the centre roller". Which is all well and good but how much of what am I supposed to put in behind these screws?

Also mine has 2 more set screws one on each of the outer rollers (see photo). I presume these need treating in the same manner as the centre one.

Dennis Z1 Rear Roller

Another rear roller question I have is. In Geoffrey Brooks's article he mentions raising the mower with a plank under the centre roller and rotating the outer rollers. This I have done and both spin quite independently and freely. What I am unclear about is this. Is this normal or indicative of a broken something inside? I have also noticed that when using it on my less than flat piece of grass (I can't yet call it a lawn) if i find a piece of ground where only the outers are in contact with it and the centre one is not I loose drive.

All thoughts and comments welcomed.