Me old dumper.

[Burnerman]

For reasons which remain unclear, I'm restoring a 1982 ex council dumper......single cylinder diesel, hand start, FWD, rear wheel steer - chuff chuff chuff....you may remember these old things.
Anyway.....the front bumper (if that's what it is) is made from thinnish channel, 6" x 6" and about 4' long. Its mounted just below the skip. The skip doesn't touch it when it tips.
Now.....the nearside of the bumper, for half its length, is completely solid steel - 6" x 6" x 3/8" plates all welded together which makes it one hell of a weight - but only on the nearside half!
What's going on? Any ideas? Really stumped here!
John

 

[Nige F]

1982 ? when I started work in 1970 the dumpers must have been 1960. Maybe the council depot fitters modded it for more traction on N/S so it would be more stable on a L/R slope. Assuming it has a normal Dif- not a locking one. PS is it hydraulic tip - or pull handle and hope.

 

[Mottie]

I’m sure I remember starting those things up as a teenager on building sites and driving them about when everyone had gone home. Had some good races with my mates. They must have been twin cylinder ones though. From memory, we got the thing turning over quickly with the handle, then threw a small lever, that started the chug chug chug and then I think we threw another lever and the second cylinder kicked in. Decompression levers maybe? I can't imagine I’d have had the strength to hand start a twin cylinder Diesel engine.

 

[Burnerman]

Cheers for your reply Nige any tips on starting the flamer without being spun round yourself
Yep, the VIN plate says 1982, but at sometime in the past it has been fitted with a dynamo - I would have expected an alternator by then. It started life with Manchester council, has a pull handle tip and a standard diff. Also rod brakes which are hopeless!
My own theory concerning the weight is that as the fat lad sits on the right at the back, this weight sort of compensates - there isn't any suspension but the rear wheels can pivot, of course.
I don't know if the weights were added afterwards or by Benford themselves - but the welding is truly hellish!
John

 

[Burnerman]

I’m sure I remember starting those things up as a teenager on building sites and driving them about when everyone had gone home. Had some good races with my mates. They must have been twin cylinder ones though. From memory, we got the thing turning over quickly with the handle, then threw a small lever, that started the chug chug chug and then I think we threw another lever and the second cylinder kicked in. Decompression levers maybe? I can't imagine I’d have had the strength to hand start a twin cylinder Diesel engine.

Yep, that's the thing! Each cylinder has its decompression lever which lifts the exhaust valve off its seat, allowing you to get some momentum up on the handle. Both twins and singles were available, each pot is around 670 cc. Electric start versions are available still, at vast expense!
Its always a relief when the starting handle disengages itself when the thing coughs into life
John

 

[Hugh Jaleak]

Try hand cranking a 3 cylinder Lister diesel on a cold morning! We had a 6" pump on a job when I first started on site from school, took 2 men to crank it, whilst flicking over the decompression levers one at a time. If you could get it firing on one cylinder then the others would usually kick in pretty quickly. (Ironically the 3" pump we also had was brand new and had electric start. )

My only theory on the extra weight would be if it was for some sort of counterbalance, I think those things would be pretty easy to flip over if you got up a good turn of speed and suddenly swerved. Maybe to help compensate something on the other side?

First lesson I was taught on hand cranking an engine, for anyone who doesn't know, is to keep your hand open and put the pressure on the handle using your palm. NEVER put your thumb over the starting handle, so if the engine does kick back, it'll pull then handle back out of your hand and not break your thumb.

If you need any tips on the old girl John, and you're on Facebook, look up a group called 'The Old Girls of Plant Hire', some knowledgeable lads on there, what they dont know about machinery isn't worth knowing.

 

[Burnerman]

Cheers for your input - appreciated!
I think you're right - the weight on the nearside front must be to compensate for a fat lad driver who sits on the right offside rear.....the weight I'd guess to be around 1cwt (that's remembering how I used to haul cement bags around in the days of yore)
Curiously though I cant see any pictures of a similar machine, but with a solid frame and no suspension a counter balance could be handy. Anyway I've fabricated a 'normal' bumper from steel angle so I'll see what happens.
My next issue - it has a hypoid diff axle on the front which seems to have been inverted to get the input shaft level with the gearbox......fair enough on that one.
However, the level plug is now 2/3rds of the way up the diff instead of the usual 1/3rd so I've no idea how much oil to put in
I'm not on Facebook - for old time teachers I don't think its recommended - but I have found a classic machinery network which could prove handy.
Have a good evening
John

 

[Hugh Jaleak]

CMN is another good site, some wonderful pictures and memories on there too. When men were men and the job got done by team work, looking out for each other and common sense, experience counted for something, and not a Hi Viz in sight.

Sure the lads on there will be more than happy to help.

 

[Avocet]

Is it possible that the heavy plate on one side is just a really rough repair using whatever they had to hand? All these small dumpers seem to have "open" diffs, so I can understand the idea of adding weight to the opposite front corner from where the driver sits, but would imagine it would be negligible as a percentage of the thing's laden weight! Oil level in the diff unlikely to be a problem if filled to the filler plug. They turn so slowly that they won't build up excessive pressure in there. Does it have brakes on the front wheels or is it all done on the transmission?

 

[Burnerman]

Thanks for your interest!
For sure, the added weight isn't a repair - the bumper channel was in straight enough order, it was simply filled in with steel for half its length!
The diff issue is still a mystery to me. I have filled the oil up to the level plug, thinking along the same lines as yourself - there won't be any frothing at these speeds. Then, I noticed an oil leak towards the top of the O/S axle tube and that turned out to be a 2.5mm hole drilled through the tube.....no ideas why! The oil wasn't leaking before, presumably because the level was much lower. Initially I thought it may have been a breather but 2.5mm is too small and in any case the axle has been inverted from standard by Benford which would have meant if it was a breather it would have been at the bottom
My intention is to discover how much oil the diff actually was designed for, and add that quantity of EP gear oil and leave it at that.
As for the brakes - I use that term with some derision - they are front only, rod operated on the drums. They are 9" Lockheed shoes of a design I can't find anywhere so I've had them relined and they do work to a small degree. The shoes float on the backplate so I'm going to use some shoe retainers to hold them better when I get a moment.....that may prevent them jamming on from time to time.
John

 

[Mursal]

No John, all the V8 Scania's especially on front spring as they get older, all start to lean towards the offside. Its because of the engine rotation fighting against the chassis and the high engine torque.
So in the event of this happening, to compensate Thwaites/Lister filled the other side bumper
Apparently .............

Yes, don't wrap your hand around the starting handle sellotape your thumb to your fingers.
Some even had a back actor .............
.

 

[Burnerman]

That's and interesting concept - many thanks for your post!
I've fabricated a 'standard' bumper so I'll fit that and see how it goes......I can always put the heavyweight back on. Snowed under with garden machinery at the moment though
John

 

[Hugh Jaleak]

Thwaites claimed you could swap from backactor to skip in about 10 minutes I think. Yet to meet anyone that's tried it and agrees with them though. The Tusker backactor design was later used for the Alldig, Thwaites attempt at producing a mini JCB. Having driven one, they could certainly dig well enough for their size, just proved pretty much useless on loader work, as the 2 cylinder Petter wasn't man enough for the job.