Middie Minnie

1964 Minneapolis Moline 602E

The M-Series Minneapolis-Moline tractors debuted in 1960, replacing the 5-Star tractors of the late 1950s in the middleweight tractor role. It was not a particularly good time for Minneapolis-Moline (M-M), as it was not for many of the legacy tractor manufacturers. International Harvester, Ford and John Deere were taking a lot of the air out of the room and the nearly 100 year old M-M was not particularly fast on it’s feet dealing with a rapidly changing market. Nor did they have a big research and development budget to market something whizbang enough to make them a market leader. Despite all that, they still put out solid products and had a loyal foundation of repeat buyers, so they hung on and gasped for air.

The M-Series Begins

The M-Series was M-M’s new mid-sized four cylinder model and sported a new look, a few new features and a power boost… at least in the gas models. It was joined by the M-504 for ‘62, which became M-M’s smallest four-wheel drive offering. They were essentially the same tractor, but the M-504 had a driving front axle. Midsized tractors were the volume models so they did well for M-M, as they did for everyone. They were not particular stand-outs in any sense but they were a dependable tractor with most of the things farmers wanted. One thing that set them a little apart was  the availability of four-wheel drive, but buyers had not yet come to regard that option as a vital enough feature yet to pony up for the extra money.

The M-Series Evolves

For 1963, the M-5 Series evolved into the M-6 line. The changes were mostly cosmetic. The M-6 consisted of two primary versions, the M-602 rear drive tractors (in many configurations… stay tuned) and the M-604 four wheel drive. This would mark a period when many of M-M’s tractors lines would be offered in two and four-wheel drive with similar model distinctions. The new M-6 line would be largely the same as the M-5, with some styling and feature changes and a little bit of a power boost for some units… at least on paper. Because our feature tractor is an M-602, we’ll focus our detail presentation on that model.

Mike and Sandie Roller’s ‘64 M-602E adds a bit of yellow to their ever-growing and diverse collection of tractors. It’s a rowcrop “E” model with an adjustable wide front axle. The breakdown of the different M-602 variants is not available but only 51 of the M-604 four-wheel drive tractors were built. The front end of the Roller’s M-M is missing some trim, notably the big “M-M” band across the front.

The M-602 had the option of LPG, gasoline and diesel engines, all displacing 336 cubic inches and having the same general architecture. The 336 shared the same 4.625 x 5.00 bore and stroke as the 504 cubic inch six cylinder. Both the 336 and 504 were over-bored by a whopping 3/8-inch from the previous 283 four and 425 six. All these engines were a legacy design that dated back to the 1930s. Slow-revving, heavy and stout, they all delivered peak power at 1500 rpm.

The working end of the M-602 shows all the standard rowcrop features, 3-point hitch with the M-M “Tel-O-Flow draft control system, 540 rpm PTO and dual remote hydraulic couplings, plus a swinging drawbar.

M-M had been fairly late onto the diesel bandwagon, having placed big (losing) bets on LPG in the early 1950s. When they went diesel, they did the same as many others and went Lanova. The Lanova combustion chamber offered a very gentle diesel cycle that most lower ends designed for gasoline could handle, so the buy-in to diesel power was relatively inexpensive to produce.

Nothing super-unusual in the operator’s station on the M-602. It came standard with power steering and a deluxe style seat.

The M-602 line was offered as a fixed wide tread standard (M-602), a tricycle with dual fronts (M-602U), a single wheel (M-602N), or with a wide adjustable front axle (M-602E), plus the M-604 four-wheel drive of course. The M-602U, N and E models were designated rowcrops and came standard with a three-point hitch. The E and M-604 models also came standard with two pairs of remote hydraulic couplings.

M-M was right on target with their Ampli-Torque, which allowed clutchless gear splitting of the 5-speed main transmission.

The D336-4 engine had a long heritage that went back to 1938 and the debut of the M-M 425 ci gas six. It was dieselized via the Lanova Power Cell system for 1953 and a four-cylinder, 283 cubic inch variant appeared at nearly the same time. They were enlarged with a 3/8-inch bore increase in 1960 to deliver 336 and 504 cubic inches respectively. The 336 was only a three-main engine but that wasn’t much of issue because it was only designed to rev to 1500 rpm. The engines had three main components, the crankcase, the cylinders which were parent bore and cast into pairs, and the cylinder heads, also cast in pairs. Today we might call them modular engines. Fuel was delivered by a Roosa-Master pump feeding injectors mounted into a Lanova style combustion chamber. Later variants of this engine used in the M-670 models were spun up to 1600 rpm and with few other changes, deliver 71 PTO horses. That was the pinnacle for this engine and the last of them were built in 1970.

The M-602 did not get a Nebraska tractor test. Most sources say M-M referred to the 1960 M-5 test as being largely the same. In that test, the M-5 delivered 58.15 PTO horsepower and 51.37 drawbar horsepower, both at 1500 rpm. Maximum drawbar pull with about 3,000 pounds of ballast was 6,751 pounds with 14.5 percent wheel slip.  M-M literature claimed 64 horsepower on the PTO and 51 on the drawbar for the M-602.

Short-Lived

The M-602 models were short lived, offered only for ‘63 and ‘64 to the tune of 4,729 units (1,771 diesel, 1,271 gas, 1,686 LPG). The M-602 were replaced by the very similar M-670 for ‘64. The M-6 line were among the last tractors designed and built by the “pure” Minneapolis-Moline company. In 1963, White Motor Company bought the controlling interest in the company and M-M became a wholly-owned subsidiary of White. White would also purchase Oliver and Cockshutt around this time and soon begin to homogenize production, adopting the most modern designs being built in the most modern factories and badge-engineering to maintain the brands. That branding would disappear when the tractors were lumped into the White brand and the Minneapolis-Moline nameplate would disappear after 1974. But that’s another story.

SPECIFICATIONS

1964 M-M M602E 

Engine:    D336-4
Displacement: 336 ci
Bore & Stroke: 4.625 x 5.00 in.
Compression Ratio: 14.8:1
Transmission: 5-speed with Ampli-Torque (5×2)
Weight: 6,550 lbs.
Wheelbase: 101 in.
Fuel Capacity: 22.5 gal.
Tires:       Front – 6.00-16
Rear – 15.5-38

 

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