John Deere was one of the pioneers of elevating scrapers in the USA. But what to do when your existing technology is out of date? The model 762 was the perfect answer. By Richard Campbell.
Deere introduced its first elevating scraper, the seven cubic yard model 840 in 1957. It was the result of mating an existing, highly modified John Deere agricultural tractor with an elevating scraper bowl manufactured and supplied by Hancock.
Not only was it Deere’s first scraper but also the construction industry’s first commercially produced self-propelled elevating scraper.
Although it was not produced in any great quantities, it certainly led the way for what was to come.
Deere replaced the 840 in 1962 with the updated eight cubic yard model 5010 (see Contractor, March 2009) and this machine cemented Deere’s place in the elevating scraper market as the 5010 was a commercial success with over 500 units sold.
Seeking to capitalise on its position, and also to compete with Wabco, which was now making rapid inroads in the elevating scraper business, Deere redesigned the 5010 in 1965, calling the new machine the model 760. Deere by now had discontinued its association with Hancock and was building its own elevating scraper bowls.
With 121 horsepower at its disposal and rated at nine cubic yards, the 760 was a very popular machine with construction as well as agricultural contractors, so it was only natural that it would be developed further.
This occurred in 1967 with the introduction of the model 760A which had a slightly increased capacity, up to 9.5 cubic yards, and was given a power increase as well, up to 152 flywheel horsepower.
The only problem with this equation was that the Deere 840, 5010, 760 and 760A were all 3-axle machines – a two-axle tractor with a single-axle scraper.
While this configuration presented no problems on jobs with adequate manoeuvring room, when it came to more confined spaces the machines could get stuck or hung up on obstacles, reducing their effectiveness and increasing cycle times.
Their major competitor Wabco, did not have these problems as from the outset, all its machines were of two-axle configuration and capable of 90 degree turns, unlike the John Deeres.
Another factor was the appearance of other competitors looking for a slice of the market share. International Harvester, Michigan, Hancock, Terex and Caterpillar were all looking for a piece of the pie by 1969.
In order to remain competitive, Deere came out with a completely new design, the Model 762 in 1975.
The 762 drew on design elements of the larger Deere Model 860, a 15 cubic yard machine that Deere had launched in 1969. At 11 cubic yards capacity, the 762 was smaller but competed head on with its rivals in the 11 cubic yard elevator market.
First production run Deere 762s had a 175 horsepower John Deere engine, a 5-speed powershift transmission (also made by Deere), 90 degree full hydraulic steering and were fitted with 23.5 x 25 tyres. Acceptance by the construction industry was immediate and Deere had another winner on its hands.
The original 762 was manufactured virtually unchanged up to 1981 when Deere made some modifications to the design, calling the revised machine the 762A.
Horsepower remained the same as the previous 762 as did rated capacity, the major change being the replacement of the 5-speed powershift transmission with a 6-speed type which allowed higher haul road speeds. The size of the brake discs was also increased to handle more heat load.
The last of the type was the model 762B which was introduced in 1986.
Featuring a power increase to 180 flywheel horsepower and retaining the 6-speed powershift transmission of the 762A, the model 762B was a state-of-the-art 11 cubic yard elevating scraper and remained in production until John Deere exited the scraper market entirely in 2005.
As such, John Deere was the last manufacturer of elevating scrapers to survive other than Caterpillar, all of the competition including biggest rival, Wabco, having fallen by the wayside.
The John Deere 762B described
John Deere was well known for the quality of its machinery and the 762 elevating scraper proved to be no exception.
Chosen engine was the Deere 6-466A six cylinder turbocharged diesel rated at 180 flywheel horsepower mated to a Deere 6-speed powershift semi-automatic transmission. Unlike many of its contemporaries, the 762B featured inboard planetary drive axles allowing for shorter stronger drive axles.
This power combination gave the 762B a top speed of just over 30 miles per hour.
Brakes were oil-cooled calliper discs on the tractor axle with air-operated shoes on the scraper.
Steering was fully hydraulic via two double-acting rams giving the 762B 90-degree steering to either side of centre and a 30-foot turning circle, making the machine highly manoeuvrable. Attached to the tractor unit by a conventional triangular hitch allowing 15 degrees oscillation, the steering cylinders were mounted high and applied force through a multiplier linkage of a design similar to Caterpillar’s.
The bowl held 11 cubic yards heaped capacity and was fully hydraulically controlled including the elevator drive.
One of the most noticeable features of the John Deere 762B was its styling which allowed instant identification of the machine as a Deere product. It was a very modern and businesslike looking machine.
Operators had the choice of an open ROPS frame or fully air-conditioned ROPS cab. The operator’s seat was a full air suspension type made by Bostrum.
The New Zealand connection
At the time the John Deere 762 was introduced, the New Zealand distributor for the earthmoving side of Deere’s business was Dalhoff & King.
Dalhoff & King appears to have done very little to promote the elevating scraper side of Deere’s product line, mainly concentrating on the small track type tractors and loaders that John Deere also manufactured. It wasn’t until the brakes came off used machinery importing that Deere elevating scrapers began to appear in New Zealand and by that stage Dalhoff & King no longer existed and its major franchises (Champion, John-Deere and Kenworth) had been dispersed.
It is not known how many John Deere elevating scrapers there are in New Zealand currently, but, just like the X-Files “they are out there”!
For the Model Collector
Very slim pickings here I’m afraid as there are no models of John Deere scrapers available in anything over 1:25 scale and even given that encouraging aspect there are still only two.
The first was designed for the sandpit and is a passable 1:16 scale model of a Deere 860. It was manufactured by US toymaker Nylint and is a good working toy – for that is all that it is.
The other is a beautifully crafted museum piece model of the first Deere elevator, the 840.
This model was manufactured by Reuhl to 1:25 scale and is quite rare as only 1000 were ever manufactured. Everything works including the elevator and the steering and a full operator’s compartment is modelled.
If large scale replicas are your thing, this is one model well worth looking out for to add to your collection.
Brief Specifications – John-Deere 762B
Engine: John-Deere 6-466A 6-cylinder inline turbocharged diesel rated at 180 flywheel horsepower at 2100rpm
Transmission: John-Deere 6-speed semi-automatic powershift
Top speed: 31mph
Brakes: Oil-cooled single disc calliper on tractor, expanding shoe type on scraper
Steering: Full hydraulic via 2x double acting cylinders
Turning circle: 30 degrees
Tyres: 23.5 x 25 E3
Capacity: 11 cubic yards
Elevator: 2-speed hydrostatic drive with 18 flights
Ejection: Sliding floor with dozer push out
Length: 32′ 6″
Height: 9′ 11″
Op weight: 16 tons (empty), 31 tons loaded
If you enjoy Richard’s classic machinery profiles you may wish to read his blog posts at www.contrafedupdate.me.