Transmission; Rear Axle - Blue Bird D3RE 2014 Driver's Handbook Manual

Transmission

Transmission Breather
The transmission has a self-contained breather at the top left rear of the transmis-
sion main housing. The breather provides a passage for normal expansion and con-
traction of air and fluid within the transmission. Be careful to avoid plugging this
breather with paint, undercoating, or any other material. A small amount of oil mist
comes out of the breather during normal operation. If an excessive amount of oil is
found in this area, the cause should be investigated.
[CAUTION] When cleaning the transmission, do not spray steam, water, or
cleaning solution directly at the breather. This may contaminate the transmis-
sion fluid.
Transmission Fluid Level
Transmission fluid cools, lubricates, and transmits hydraulic power. Always maintain
proper fluid level. If fluid level is too low, the torque converter and clutches do not
receive an adequate supply of fluid and the transmission will overheat. If the level is
too high, the fluid aerates, causing the transmission to shift erratically and overheat.
Fluid may be expelled through the breather or dipstick tube when the fluid level is
too high. Please see your Allison Transmission Operator's Manual for information on
how to check fluid levels at both cold and hot engine temperatures. Allison recom-
mends the use of Transynd Synthetic transmission fluid.
Transmission Fluid And Filter Changes
Please see your Allison Transmission Operator's Manual for procedures to change
transmission fluid and filters, and the intervals at which these should be done.

Rear Axle

All drive axles have a vent on the top of the axle housing that allows the axle to
breathe as the axle temperature changes. The vent must remain open to prevent seal
failures. It is normal for the vent to ooze a small amount of lubricant.
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DRIVER'S HANDBOOK