Early vs Late Farmall 706

The Farmall 706 and 806 tractors debuted in the summer of 1963. Both were badly needed touchdowns after several unexpected years of John Deere dominating the game. The 806 debuted with the new D361 engine but the 706 used an updated version of the D282 six-cylinder engine which had debuted in the late ‘50s and powered several IH tractors, including the somewhat notorious ‘58-63 560.

Thomas Geise’s 1963 Farmall 706 is a narrow front model and shows the 706 lines in the early days. Comparing it with the later unit nearby, you can see some detailed differences, such as the clamshell rear fenders. Also different is the “Farmall” badge.

The big news of the 706 was not the engine but the rest of the tractor, particularly the final drive. The new transmission had a four-speed main box, with a two-speed range box. It featured an optional hydraulic TA (Torque Amplifier) that could split each gear, instantly and with no clutching. The 06 tractors also featured a centralized, three-pump hydraulic system of greater capacity than ever before offered. Not only did it power remotes for hydraulic implements, but it also operated an integral hydrostatic power steering system, and hydraulic power brakes and had juice left over for the new hydraulic TA and a hydraulically actuated PTO. Yeah, the 706 was the tractor the 560 should have been.

Robert Keener’s 1967 Neuss-powered 706 illustrates the 2nd Generation tractor. The second generation 706 emerged on November 1, 1966, at serial number 37237. Generally speaking, “Second Generation” is indicated by the addition of the D310 Neuss engine. Approximately 9,410 Neuss-powered 706 Farmalls were built. Keener’s is a relatively early 706. It’s a wide front model which had proven to be more popular over time than the narrow front. The rear fenders are the flattop type that was called the “Deluxe” fender. They debuted on 1206 in ‘65 but became optional starting around 1966 and became very popular.

The 706 was a big tractor in its class, with a high seating position placed forward of the rear axle for an improved ride. The plush (by tractor standards) seat was adjustable and featured a suspension system. It could be ordered with dual 540 and 1000 rpm PTOs. It came optional with Front Wheel Assist, using a Coleman axle. A cab was also optional, which was later available with air conditioning. With its bigger 806 brother, the 706 was definitely the shape of IH things to come and launched the company into a very successful decade.

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The D282 dated back to July 1958 and appeared in the 560 tractors. The D282 engine was an adaptation of the successful Black Diamond series gas six architecture. History has judged it a successful engine, but just barely. It was part of a family of six-cylinder engines that were built in three displacements, 236 (short stroke) and 282 cubic inches with dry sleeves and 301 cubic inches as a parent bore, both long stroke. With only four main hearings and fewer head bolts than it probably should have had, D282 had a reputation for not being durable in hard use and needed to be babied a little. It was fuel efficient but limited in power. There were four cylinders that used the same architecture and a short stroke parent bore variant that didn’t make production. Though they never put the D282 in trucks, its parent-bore D301 was used in trucks and made 112 horses at 3000 rpm.

The Farmall 706 was offered with either narrow or wide adjustable front axles and being a row-crop tractor, an adjustable rear track width. At the working end were a new 3-point lift and dual range PTOs. Of course, gas and propane-powered variants were sold but the vast majority were diesels. A fixed track, wide front International (Farmall being the row crop tractor designation) version was built for utility, industrial, or wheatland use but they were only about 20 percent of the total 706 productions.

1st Generation: New Tractor, Carryover Engine

The 706 was powered by an updated version of the D282 diesel that had debuted in the ’58 560 models. It was a 282 cubic inch, naturally aspirated, indirect injected, dry-sleeved, four-main bearing six-cylinder engine that featured glow plugs for cold starts. It had picked up more than 10 PTO hp from 61 to 72 PTO horsepower in the translation from the 560 to the 706, mainly by tuning the pump and raising the peak power rpm from 1800 to 2300. At that output, the final drive was essentially bulletproof.

The D310 was everything the D282 wanted to be but wasn’t. It had a stout 7-main bottom end, wet sleeves, and direct injection. It made about 4 more rated horsepower than the tractor but unlike the D282, it was not frail and could be used to its full potential. For most who have driven both versions of the 706 state, there is a bigger difference in apparent grunt than the number on paper would indicate. The D310 in the 706 was rated at 76 PTO horsepower at 2300 rpm but when used as a truck powerplant, as it was in Europe and Australia, it could deliver 92-95 horses at 3000 rpm. Unlike the D282, the D310 did not have glow plugs. The early D310s had a low 15.9:1 compression ratio and have the reputation of being poor cold-starters. It did have an etherizer, a device that allowed the operator to add a squirt of ether from the comfort of his seat. The Bosch VA pump also had an enrichment device but if you lived in a cold climate, you were using that block heater for reliable starting. Strangely, the D282 with glow plugs has the same cold-start bad rap.

2nd Generation: Old Tractor, New Engine

There were many small changes to the 706 in its lifetime, but only one really big one. For the 706’s last year, the aging D282 was replaced by the German-built direct-injected D310 (309.6ci), which made a few more ponies than the D282 and was more fuel efficient. Built by the German IH subsidiary, Neuss, the D310 emerged from the Neuss-on-Rhine factory starting about 1965. The Neuss factory had been owned by International Harvester since 1908 but didn’t start building tractors until 1936. After being destroyed in World War II, the factory reopened in 1946 and soon began building tractors and engines. At first, they were American designs but they soon began building engines designed in-house.

The working end of the early 706 is largely the same as the later… dual 540 and 1000 rpm PTOs and stout 3-point hitches with draft control. Differences you can observe are in the fenders, and the clamshell style shown here, which were the only option through 1965. Instead of having a fixed swinging drawbar, this older 706 has a drawbar attachment added to the 3-point hitch.

From the operator’s point of view, there isn’t much to choose between the early and late 706s. The layout is largely the same.

By the 1960s, new engine designs were planned and a new line of four and six-cylinder engines went into production in 1965. At first, these engines were allocated only to the European market but as the North American market expanded, IH needed more powerplants to supplement their own tractor. Neuss had some extra production capacity and it kept the German factory working cost-effectively at full speed. Among the engines chosen for fitment into American tractors were the Neuss D310 and a little later the Neuss D358. They were both direct-injected engines with a 3.69-inch bore, but the D310 had a 4.39-inch stroke while the D358 used a 5.06-inch stroke and gained nearly 50 cubic inches.

Faded Away

The 2nd generation 706 debuted in 1967 but was soon updated to be a member of the new 56 series tractors that appeared as the 756 for 1968. It was largely the same tractor as the 706 but with significant restyling. The 706 Farmall was an extremely popular IH model, with nearly 47,000 built between the end of 1963 and 1967. You can add to that nearly 5,500 standard treads 706 International-branded tractors. Nearly 9,500 of the Farmall total were last year 2nd Generation models. So, yeah, you can definitely say the 706 was a touchdown tractor for International Harvester and one that is still fondly remembered today. And still used on farms around the country.

The later 706 has a more commonly seen swinging drawbar with the 3-point free for use on other implements.

SPECIFICATIONS

Early IH Farmall 706/ Late Farmall 706
Engine: IH D282/Neuss D310 inline six
Displacement: 281.3/ 309.6ci
Bore & Stroke: 3.69 x 4.39/ 3.88 x 4.38 in.
*282 PTO Power: 72.42 hp @ 2300 rpm
**310 PTO Power: 76.09 hp @ 2300 rpm
*282 Drawbar Power: 63.30 hp @ 2300 (no ballast)
**310 Drawbar Power: 65.70 hp @ 2300 (no ballast)
Compression Ratio: 18.2:1/15.9:1
Fuel Capacity: 33 gal.
Transmission: 8-speed (4×2) standard
16-speed (4x2x2) optional
Weight: 8530/9160 lbs.
Tires: 6.50-16 front (narrow front)
15.5-38 rear (std)

*Fuel Consumption: 5.5 gph @ max power
**Fuel Consumption: 5.1 gph @ max power
*Drawbar Pull: 8026 lbs @ 14.57% slip (max ballast)
**Drawbar Pull: 8416 lbs @ 14.90% slip (max ballast)
Top Speed: 18.5 mph (both)

*As Rated by Nebraska Tractor Test 856
**As Rated by Nebraska Tractor Test 955

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Jim Allen

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Early vs Late Farmall 706

Early vs Late Farmall 706