Johnson 2HG dumper restoration, Petter powered dumper

My Johnson 2HG Dumper Restoration Project

I got my dumper on 31/01/06 for £100. It was mechanically sound but in need of a total restoration and repaint. It's a manual tip variety and starts with a handle. I thought it was a nice restoration project because it's quite unusual as it has rear wheel drive unlike most dumpers which have the driving wheels under the skip. Once completed, the dumper can tow my Fleming Micron digger around, move spoil and be used for bringing back firewood.

Johnson 2HG Dumper

I had no idea who made the dumper when I got it. Dumpers are often hard to identify so I put a free advert and picture in Classic Plant and Machinery magazine in the hope of finding out a bit more. I am grateful to Alistair who got in touch and who was an apprentice for Johnson's in the 70's. He told me the dumper is a Model 2HG. The "G" denotes gravity tip as opposed to hydraulic. It was made by Johnson Machinery Ltd who were based in Adswood, Stockport, Cheshire. Martin very kindly telephoned and posted me a photocopy of the workshop manual. Jim Perkins (of Petter fame) also responded to the advert and was able to tell me from the engine number that the engine was built in November 1967. I think we can safely assume that the dumper is a 1967 or 1968 machine. That makes it just a few years older than me!

Basic information about my dumper

Johnson Model 2HG
2 wheel drive
1 ton capacity when fully loaded
Petter PH1 single cylinder diesel engine number 35688PH1 Model 52. 6.75 hp at 1650 rpm.
3 speed gearbox with reverse
Rod operated drum brakes on the rear axle only
Probable year of manufacture 1967 or 1968
Original colour - Orange
Early models had a toothed rubber drive belt, others (including mine) have a chain
Some 2HG dumpers have the Petter AVA1 engine, some the Petter PH1

Detailed technical information and sales literature (all in PDF format)

Workshop manual and parts list (45 pages) - click here
Original Sales Brochure - click here
Petter PH1 Engine Datasheet - click here
Petter PH1 Operators Handbook - click here
Petter PH1 Workshop Manual - click here
Petter PH1 Parts List and Exploded Diagrams - click here

The restoration

I had good intentions of starting to restore the dumper fairly soon after getting it. However, I was so busy with other jobs and family commitments it didn't actually enter the garage until 26/10/08 and work started February 2009. One of the problems was tidying the garage out to make space which took a long time as I had to get rid of 12 years worth of accumulated junk. I did use the dumper in its un-restored state in 2007 and 2008 for bringing back a large load of firewood. This confirmed to me just how useful it is.

Although the dumper looks awful it starts and works perfectly well. Here it is loaded with logs and sporting its new air filter bowl which my mate Rodney kindly donated.

Here's the dumper finally in the garage. I cannot believe that I have actually managed to make enough space for it!

Aim of the restoration

The aim of the restoration is to get the dumper back to good useable condition so it can be preserved, not to turn it into "as new" condition.

Plan of works

The rear chassis is not saveable so it needs to be stripped of all parts and a new chassis fabricated using the old one as a pattern. This will mean separating the two halves of the dumper.
Clean, repair and paint all parts as necessary before refitting them
Build some mudguards as illustrated in the Workshop Manual as the originals have disappeared
Make a new handbrake lever as the original has disappeared
Get a new seat
Repair the tinwork on the engine, clean and repaint it and give it a service
The front chassis is saveable and needs to be cleaned and repainted
The skip needs repairing and repainting (I think it can be saved at this stage but will let you know)
Fit 3 new tyres (already done 1 as it was bald and I don't like getting stuck)
Investigate getting a number plate for the dumper and the cost of tax and insurance

Stripping the rear chassis

The footplates are badly rusted and replacements will need to be fabricated.

Removing the seat and footplates was the first job I tackled.

Most of the bolts on the dumper are so badly corroded that they just have to be cut off with the angle grinder. Check out the size of the giant rust flake!

The rear chassis is made of 4x2 inch channel which is too rusty to save. The bucket was to catch the oil from the chain case. All that came out was grey oily water!

Here's the clutch on the Petter PH1. Its a Borg and Beck and looks in pretty good condition. The engine is unbolted but I need to borrow an engine crane to lift it off.

Here's the gearbox and chaincase removed and stored. The cardboard box contains any bolts that are re-useable.

Here I am cutting the bolts on the steering box bracket. These were hard to get to with the grinder so I resorted to a cold chisel and hammer. This ended the work for the first week

We have borrowed Gordon's engine crane and here the boys are helping to lift the engine off the dumper. Its dry weight is 185KG according to the Petter Data Sheet from Jim Perkins.

The Petter PH1 safely lowered to the floor where it can sit while the new chassis is fabricated.

Under the engine there was a nice area of original Johnson orange paint. Note the elongated mounting holes so the chain (or belt) tension can be adjusted.

Removing the pedal assemblies was fairly easy as most of the bolts would undo. I had to drill out one rivet and heat the end of the throttle linkage to knock it off.

The pedals are all heavy duty forgings and with a bit of cleaning and repair will be fine.

One side of the axle is leaking oil which has gone onto the brake linings. That's going to need attention. See how rusty the axle bolts and chassis rails are on this side.

The axle was lowered after grinding off the nuts. I now need to tidy up the removed parts, move the dumper forward slightly and separate the front and back sections.

Splitting the dumper in half

Before working under the dumper I ensured that the front wheels were chocked and the rear chassis was safely supported on wooden blocks. I also took the precaution of tying a rope from the skip to the front chassis to make absolutely certain it couldn't tip if the rather worn release mechanism did suddenly let go while I was underneath. The curved runners would make a deadly guillotine for any fingers in the way.

The large castle nut on the pivot shaft was hard to remove as it had a split pin through it which was rusted solid. I broke the split pin off and undid the nut with a large socket.

The steel collar. This had a completely rusted grub screw so I had to cut it off with the angle grinder. I will either get a replacement made or weld the collar back together.

Once the nut and collar were removed I supported the rear chassis with the engine crane and using a crowbar levered the 2 halves of the dumper apart.

Rear chassis propped up ready for measuring up for the new steel.

Front half of the dumper carefully supported by axle stands and wooden blocks.

This is the cutting list for the steel I need to make the rear chassis. I accidentally left off the 35 5/8" piece of channel. As Homer Simpson would say, "DOHHHHH"!

The Steel

I ordered the steel from D C Ould at Roche. They could supply everything except the chequer plate and cut the channel and flat bar to length on their oil fed saw so it is all nice and square. This will save me a lot of work. I collected it on 27/02/09 and over the following weekend started drilling the holes prior to welding the chassis together. Unfortunately I had left one piece of channel off the list by mistake. Rather than driving all the way to Ould's again I popped into a local fabricators and luckily they had a piece of channel in their off-cuts which I purchased for £5.

I have managed to get a small piece of chequer plate from another local fabricators. They only charged me £5 for it which is great as I now have all the steel for the rear chassis.

I have made a start on drilling the new pieces of steel so they have all the right holes in the same places as on the old chassis.

I'm using the old chassis as a sort of workbench and laying the new steel out on top helps with measuring and marking out the holes with a tape, square and centre punch

Checking the new holes for accuracy by offering up the old removed parts.

The nice thing about working on the dumper is that all the holes are set out in easy Imperial measurements. Good old British pre-computer manufacturing

Having finished drilling all the steel, I clamped the four main parts to the old chassis. I used all my clamps and some borrowed ones and then resorted to bolting scraps of metal through the pre-drilled holes to make sure the new chassis is the right size. I also checked the diagonals before tack welding it together. I then re-checked before putting some proper welds on.

My pillar drill has been invaluable on this job. It's only a cheap Chinese one but I have had it for years and it works perfectly well and can accept Morse taper bits.

I am using a Silverline fan-cooled arc welder for the welding. It was only £30 and welds pretty well. It was very noisy but I gave the case a bash and that cured that problem.

Click here for more on the dumper restoration on PAGE 2

More Johnson Resources

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