Service Manual

7-7Power Max Service Manual

AUGER GEARBOX

Fig 091 DSC-0061

The square cut ring on the impeller shaft is not an oil

seal. It is a wiper ring that has a tendency to pull down

to the shaft when the shaft begins to turn. The bushing

next to the ring deﬂ ects most of the oil that is thrown

towards that area. The loose ﬁ t provides a vent for the

case (Fig. 091).

Fig 090 DSC-0028

9. Now inspect the worm and worm gear. If either

are damaged replace them both. When gears run

together, they develop wear patterns unique to the

two of them. Replacing only one gear will result in

early failure (Fig. 090).

Failure Analysis

Occasionally a drop of two of oil will get between the

bushing and ring. When the auger drive is disengaged,

the ring will relax and that oil might drip into the auger

housing. At this rate the machine can be used for several

years without any signiﬁ cant oil loss. The yearly oil check

is more than adequate to compensate for this.

If there is a signiﬁ cant amount of oil coming out of this

area, it would indicate that the gearbox has been at a

severe operating angle or the bushing is badly worn.

Oil on the bottom of the gearbox can result from a leak

on any part of the case. As there is no internal pressure,

any leaking oil runs down the side of the case and

collects on the bottom until there is enough to drip off.

The source of the leak can be difﬁ cult to see. Sprinkling

some powder on the outside of the gearbox will usually

show the oil trail. The type of powder used is not

important. Just something that will stick to the oil.

When you open a gearbox that has had the gears

fail, the remaining oil will likely appear as a small

puddle of very thick grease in the bottom. Worm gears

normally create friction due to their sliding action. When

something goes wrong, not enough oil, poor quality oil, a

problem with the gears, or just a gear or bearing wearing

out, the friction becomes abnormally high. The remaining

oil is cooked down to a very thick residue. This can be

the result of a failure, not the cause.