SERVICE REPAIR
N30XMDR2 N45XMR2 [F138]
630 SRM 613
HFK300 and 400 Master Drive Unit
HFK300 and 400 Master Drive Unit
GENERAL
CAUTION
Certain specifications and procedures differ
depending upon the type of MDU. Verify the
type of MDU by inspecting the MDU housing.
The designation 300 or 400 is embossed on the
housing. The final drive ratio is 14.5:1 for the
HFK300 MDU and 14.2:1 or 20:1 for the HFK400
MDU.
CAUTION
Some of the hardware used on the MDU and
traction motor is metric. Use the correct tool
to avoid damage.
The HFK300 is used on the N30XMR, N30XMR2,
N40XMR, N40XMR2, N25XMDR, N25XMDR2,
N50XMA, and N50XMA2 models.
The HFK400
is used on the N45XMR, N45XMR2, N30XMDR,
N30XMDR2, N30XMXDR, and N45XMXR models.
This section has a description and the repair and ad-
justment procedures for the parts of the master drive
unit (MDU). The traction motor, steering, and brake
repair procedures are in separate sections.
This section contains removal, installation, repair,
and adjustment information for master drive units
(MDU) used on the narrow aisle series lift trucks.
The traction motor, steering system, and brake re-
pair information and procedures are not in this sec-
tion.
There are two different types of MDUs used on this
series of lift truck models, Hurth Models HFK300
and 400. The major difference is the gear ratio. The
lower case and internal parts of these MDUs are very
similar.
DESCRIPTION
The main component parts of the MDU are the case,
the motor pinion and large gear set, the pinion and
spiral bevel gear set, the bearings, and the axle and
wheel. See Figure 1. The traction motor fastens to an
adapter ring fastened to the MDU. This adapter ring
is part of the large ball bearing and allows the MDU
to turn on the axis of the traction motor for steering.
The traction motor does not turn with the MDU.
Six capscrews fasten the large ball bearing and
MDU to the articulating axle. There is a small
pinion gear on the traction motor armat