Terex had very big shoes to fill when it replaced its iconic TC-12/82-80 track type tractor with the new model 82-50 in the company’s product line. While not an instant success, time would see the 82-50 well regarded by those who owned, operated and maintained it. By Richard Campbell
Released in 1973, the Terex 82-50 was not the first Terex track type tractor to have the 82-50 designation.
That honour goes to an experimental version of the (then) Euclid 82-40 which was trialed in 1967 but did not proceed past the prototype stage with only one pilot machine being built before the project was shelved.
However, Terex were well aware that current upgrades to its existing TC-12 dozer, (renamed the 82-80 in 1966), could not compete in the large tractor market for much longer, and that a new tractor was required.
Sales of the existing 82-80 had slowed dramatically and something had to be done.
A lot of planning went into the new tractor, initially known as the Model 972 which first appeared in 1971 and was powered by a General Motors 12V-71N naturally aspirated diesel with an Allison powershift transmission.
Several test machines (or “mules” as Terex called them) were sent to various job sites for testing, and the overall impression of the new tractor was good, but that it needed more power and the relocation of some components, plus improvements to operator visibility.
Following the necessary modifications and design changes, the new tractor was put into production at Terex’s Hudson, Ohio manufacturing facility as the model 82-50AA and the first units were delivered in 1973 to much advertising fanfare as only General Motors could muster.
Weighing in at around 48 tons with blade and rippers, the 82-50 was powered by a General Motors 12V-71T turbocharged V-12 diesel engine that produced 370 flywheel horsepower, connected to an Allison CRT7031 3-speed powershift transmission.
As with all previous Euclid/Terex track type tractors, the 82-50 had planetary final drives and a radiator mounted at the rear of the machine, and driven by an extension shaft, out of harm’s way.
This made the machine particularly suitable for landfill or land clearing operations where clogging/damage to the radiator’s fins in a conventionally configured machine was a problem.
It also kept the operator warm in the winter!
Care had been given to the undercarriage to make it as resilient as possible. However, quite early in the machine’s service life, a problem arose with the bottom track rollers separating from the track frame, so a hasty campaign was undertaken to ‘beef up’ the bottom roller mountings of all machines in the field.
This required the track frames to be removed from the machine and a series of steel blocks welded in place to prevent the problem reoccurring. All this was done under warranty and must have cost Terex hundreds of thousands of dollars
The standard 82-50 undercarriage consisted of an 84” gauge track frame with an oscillation shaft for each frame just in front of the sprocket and joined at the front by a pinned equalizer bar to maintain track frame alignment.
Thirty-eight-section sealed tracks with 24-inch extreme service shoes were standard ex-factory but other options could be fitted at the buyer’s request.
Track tension was maintained by a nitrogen charged, hydraulically adjusted recoil cylinder on each track frame.
ROPS mountings were standard equipment and the machine could be equipped with either a ROPS canopy (manufactured by Medford) or a deluxe ROPS cab.
The majority of 82-50s were delivered with the ROPS cab.
Even for 1973 the operator’s controls were quite basic with the twin steering levers mounted just ahead of the transmission selector to the operator’s left. To his right were the blade and ripper controls with a master brake pedal and engine decelerator located on the floor.
Visibility from the ROPS cab was average at best and not particularly quiet!
The standard 82-50 bulldozer blade was a 13 foot semi-U type with a 16 foot full-U as an option.
There was also a cushioned push blade option.
No angle blades were offered as Terex considered the 82-50 a bulk production machine, not a trail builder. Terex built all its own blades for the 82-50.
Rippers were supplied by Ateco or CRC-Kelley with the most popular being the Ateco V-LPAS Vyba model with three shanks.
CRC-Kelly offered a massive single shank KR400 radial arc ripper which could be sunk to a depth of almost 11 feet for hard rock applications.
For logging or recovery operations, a Hyster W12E or Carco 120PS winch were adaptable to the 82-50.
Terex was, unfortunately, never at the top of the list when it came to track type tractor suppliers, and the Terex 82-50 faced some fairly hefty competitors in its size class.
It competed with the Caterpillar D9G (an industry standard, later replaced by the improved D9H), the Komatsu D375, International-Harvester TD30 (which turned out to be very unreliable), and the Fiat-Allis 31.
End of an era
Although the 82-50 replaced the well-regarded model 82-40 in Terex’s dozer line-up, unlike the 82-40, the 82-50 was not a big sales success for Terex.
In continuous production from August 1973 until early 1986, several component upgrades were undertaken throughout the machines production life to improve and enhance its performance and reliability.
Perhaps the biggest of these was the redesign of the front nose cone to accept twin lift cylinders in place of the single one that had been a Terex spotting feature since hydraulics were introduced to the Euclid/Terex dozer line.
For the last three years of production, the 82-50 was known as the Terex D800 to align it with the other Hanomag-manufactured machines that were now in Terex-IBH’s stable.
The last machine rolled off the assembly line in 1986 and was also the last track type tractor to be produced at the Hudson, Ohio factory.
The New Zealand connection
Several Terex 82-50s were imported by (then) New Zealand distributor Clyde Engineering, and a series of public events were held to demonstrate the machines to contractors and Government officials.
The first purchaser was Feast Contractors, a long time Euclid/Terex user.
Unfortunately, Feast’s machine was taken over by Downer Mining after that company took over Feast’s Waipuna opencast contract at Huntly in the Waikato.
The remains of this machine are now buried in the fill at that site, along with a whole lot of other machines that should have been preserved.
Mike Lambert also used a Terex 82-50 with a custom wood chip blade to work the woodchip pile at Port of Tauranga for a number of years.
For the model collector
Only one model of the Terex 82-50 exists in model form.
Originally manufactured in 1974 by NZG, it has been re-released several times over the years, the last time with Terex-IBH livery.
It is no longer manufactured but is generally available on Ebay and through Buffalo Road Imports.
Generally accurate, the model is equipped with the standard semi-U blade, Ateco Vyba 3-shank ripper and a ROPS cab.
The big downside to this model is that it is to 1:40 scale and looks totally out of place amongst 1:50 collections as it is way too large.
Until another manufacturer has the good sense to model an 82-50, the NZG model remains your only choice.
Brief Specifications – Terex 82-50AA
Engine: General Motors 12V-71T turbocharged V-12 diesel rated at 370 flywheel horsepower @2100 rpm.
Transmission: Allison CRT7031, 3-speed full powershift transmission
Top Speed: 7 mph
Brakes: Oil-cooled multiple disc
Steering: Hydraulically actuated multiple disc clutches
Track: 38-section, sealed
Std.Shoe 24” extreme service (other options available).
Length: 16’ 2” (bare)
Width: 9’ 5” (bare)
Height: 9’ 2” (to top of ROPS)
Operating Weight: Approx. 48 tons with semi-U blade & 3-shank ripper
Caption: Looking very smart in a fresh coat of paint, this 82-50 has the seldom fitted open ROPS canopy.
The canopy was supplied by one of Terex’s preferred attachment suppliers, Medford of Oregon.