Antique Wheelhorse Garden Tractos

The '500' Special

By "Wild" Bill Pearson

The Wheel Horse company has had a relationship with the Indianapolis Motor Speedway and the Indy 500-mile car
race since the early 1960's. RECO Sales, which is a division Radio Equipment Company, (1500 Stadium Drive,
Indianapolis, IN) was the distributor of Wheel Horse products that sponsored an annual Indy 2-1/2 mile race, using
Wheel Horse garden tractors. Local personalities would drive the Wheel Horses one lap around the Speedway;
hence, the name the Indy 2-1/2. After doing this over the years, Wheel Horse tractors became well known at the
track, for towing the racecars from the garage area to the pits.

In 1968, Wheel Horse decided to commemorate this activity by building a special model called the "500 SPECIAL".
They manufactured it for only one year. It was adorned with a decal that resembled a red and white racing stripe
down the center of the hood. Blue and white racing stripes blazed both sides of the hood that read WHEEL HORSE
500 SPECIAL. On each side of the hood stand were decals of two cross-checkered flags. The number "6" was later
added to the cross-checkered flag decal to signify the 6-horse power Tecumseh H-60 engine that powered the "500
SPECIAL". At some point during that same year, the "6" was removed from the crossed-checker flag decal. As a
result, you will find that some "500' SPECIAL's" will only have two crossed-checker flags on the side decals.

The Tecumseh H-60 engine was a recoil start version, but the ignition system did use a key type switch, which
would ground out the engines ignition points to shut the engine off. The transmission was a Uni-drive, model
5053, three-speed that had brakes by way of an external drum and a band controlled by a clutch/brake pedal. In
1968, Wheel Horse came out with a wider rear fender that easily covered the 6.00 x 12 tires. The front tires were
4.00 x 8 with a diameter of 16 inches. As with most other Wheel Horse models of this period, the wheel and horse
logo was embossed in the vinyl on the seat. This model was available with your choice of a 32- or 36-inch gear
drive mower deck, a 42-inch sickle bar mower, 32-inch snow blower, 42-inch snowplow, 32-inch disc, 8-inch
plow and a large assortment of pull behind attachments. Not bad for a 6-hp tractor! The tires could be dressed as
well, with the "new for 1968" chrome hubcaps which included a painted wheel and horse logo. If more weight was
needed, cast iron wheel weights were also available.

The model number to order a "500 SPECIAL" back in 1968 was 1-3631. Some time after production of the 500,
dealers voiced complaints that this recoil start engine was a tough selling point. As a result, dealers began manually
converting the system to electric start. It has been said that the "500 SPECIAL" was only sold only in three states:
Indiana, Michigan and Ohio, but I have not found any records with RECO Sales to prove this. The "500 SPECIAL"
tractors have been located from Illinois to the New England states. My "500 SPECIAL" was found in Winston Salem,
North Carolina. If these tractors were truly only sold in those three states, it just goes to show how much people
loved their Wheel Horse "500 SPECIAL" if they hauled it with them when they moved!

Publisher's Note: The total production of 500 Specials is still a mystery. Based on research, I believe up to 3,000 of
them might have been built. One thing is for sure, they are hard to find, especially one with the original engine. It
would make a great addition to any Wheel Horse collector's lineup!

Uni-Drive: The Back Bone of the Horse

By Wild Bill Pearson

Aside from appearance, most garden tractors are very similar with the exception of a few accessories. More
importantly is what's in the business end of the tractor: the transmission. Cecil Pond designed Wheel Horse's
Uni-Drive transmission in 1957. It had three forward speeds and one reverse, which was introduced in 1958 on the
Ride-Away Junior tractor. The Schafer Gear Works, located in South Bend, Indiana, manufactured the gears that
went inside of the Uni-Drive.

The first versions of the Uni-Drive were the models 5003 and 5010, affectionately known as the side plate
transmission. All Ride-Away Juniors and Suburban series tractors produced from 1958 through 1961 were equipped
with these units. The center section of the transmission gear housing was made of cast iron. The shafts were held in
place by bearings. These bearings were held in place by rings welded on the sheet metal side plate. This design
wasn't bad for a lightweight tractor. The gears were a straight-cut automotive type gear giving plenty of strength,
but the axle tubes became weak. These tubes were welded to the side plates without any gusset or support. Because
of this, when a hefty operator used the tractor over a length of time, the axle tubes would bend and crack.

Another problem with the model 5003 was the large teeth on the pinion and brake shaft gear (bull gear). This set
of gears had large, strong teeth. Inevitably, when they meshed there was very little tooth-to-tooth contact. An
updated gear set was introduced in 1960. It had a finer set of teeth on the two gears, providing a greater
metal-to-metal contact area with no slippage, and greater strength. There were two different designs: One design
had a one-piece casting; the second had a bolt-on-bull gear.

In 1961 the Uni-Drive model 5007 was introduced for use on the Suburban models 551 and 701. The 5007 was a
two-piece, cast iron transmission. The same basic design was used through 2007. From 1961-69 there were two
designs of the three-speed: one for the small and medium tractors; the second for the large model tractors. The
distinction between these transmissions was the differential type and axle diameter. The small and medium tractors
had a differential with spur gears and one-inch diameter axles. The large tractors used automotive bevel gears in the
differential and 11/8" diameter axles. A trick that garden tractor pullers maneuvered back in the 1960s was to use
the bigger 11/8" axles and bevel gear differential in the smaller Wheel Horses.

In 1967 a new Uni-Drive transmission, known as the model 5060 was introduced. It had 6 forward speeds, which
doubled the tractor's working capacity. A Hi/Lo sliding gear provided gear reduction to be multiplied by four, thus
allowing the tractor to use more power at slower speeds. In addition to having low-range capabilities, the model
5060 also sported a posi-traction type differential. The differential carrier had ten pinion gears which used a
cylindrical spring to hold pressure on the pinion gears which kept them rotating at a consistent speed. The
weakness of this design was the thin area of the carrier housing. Often times the housing would crack, allowing the
gears separate. When the eight pinion differential housing was released, you could retrofit your tractor with an
eight-pinion carrier in place of the ten pinion carrier.

In 1971, Wheel Horse came out with a new and improved transmission with heavy-duty gears. There were and two
styles of differentials made with this design. The first type still used pinion gears with pin-type shafts holding them
in place. The second one used a one-piece pinion gear. This Uni-Drive design was produced through 1975.

The heavy-duty Uni-Drive with 11/8-inch diameter axles and 8-pinion differential was launched in 1970 and used
with minor changes through 2007. A light-duty Uni-Drive was also used. It had one-inch diameter axles and a
4-pinion differential. Strangely enough, you could get this transmission in a Wheel Horse equipped with a 16hp
Kohler (the 1982 model SK-486). Even more unusual was the fact that the 1976 and 1977 model B-60, with less
then 7hp, came with the heavy-duty Uni-drive transmission.

The gear ratios for the Uni-Drives built from 1958 through 2007 remained the same for gears one through three
and reverse. When shifted into the low range, the ratio is multiplied by four. The chart below shows these ratios in
both hi and low range.
Uni-Drive Gear Ratios
Hi Low
1st gear 66.8 to 1 267.2 to 1
2nd gear 42.4 to 1 169.6 to 1
3rd gear 24.6 to 1 98.4 to 1
Reverse 51.5 to 1 206.0 to 1

Now you know why a Wheel Horse is tough enough to pull tree stumps out of the ground!