New Cast Axle Housing, Replacement
M-461-002
(Feb 2007)

Valid for
All Mack CXU,CHU,GU,MRU,LEU,TD models

Case description
Beginning with September 21, 1998, production, the S441 axle housing was changed from a steel casting to a nodular
ductile iron casting. The S58 and S65 axle housings were also changed to a nodular ductile iron casting at a later
time. These cast iron housings include replaceable induction hardened steel spindles (inner bearing journals). Along
with the release of these new cast axle housings, the rear axle model designation has been changed as follows:
Previous Model Number

New Model Number

S441

S462, S522

S58

S582

S65

S652

The identifying features of the ductile iron housings are the two MACK Bulldog logos cast into the back-side of each
axle housing and the machined flat surface on the front of the axle bowl (refer to the illustration below).
Housing Identification

Parts
The part numbers for the new cast iron housings are as follows:
Part No.

Description

Replaces

19QF5287

S462, S522 axle
housing with cam
brakes

19QF4416P4

19QF5287P2 S462, S522 axle
housing with disc
brakes

19QF4416P5

19QF5287P3 S582 axle housing
with cam brakes

19QF4416P3

19QF5287P4 S652 axle housing
with cam brakes

19QF4416P2

Repair
The ductile iron axle housings are basically direct replacements for the cast steel housings. Fastener tightening torque
values for spring clips (U-bolts) and carrier-to-axle housing bolts remain the same. Refer to the Maintenance and
Lubrication Manual, TS494, for these torque values. For the S582 and S652 axle housings, however, suspension
attachment hardware is different than the hardware used with the S58 and S65 axles. On both the S582 and S652
axle housings, the inner spring saddle bolt holes on the right-hand side of the housing are threaded, requiring the use
of two new bolts (part no. 6AX1160) and washers (part no. 35AX1534) in place of the nut and bolt arrangement
originally used on the S58 and S65 housings.
Note: The 1/4" spacers (part no. 71RU21707 for the S441 and 35AX338 for the S58 and S65 axle housings) between
the inner bearing and spindle on the cast steel housing are no longer used on the new ductile iron axle housing.
The hardened steel spindles (inner bearing journals) are replaceable on the ductile iron assemblies. Refer to the chart
below for the part numbers of the spindles and seal rings for the different axle assemblies.
Axle
No.

Spindle Part No.

Seal Ring Part
No.

S462,
S522

4103–5010319527
(cam or disc brakes)

4103–
5010319724

S582

4103–5010319786

4103–
5010319757

S652

4103–5010319802

4103–
5010319757

Note: The replacement spindles are not interchangeable with the replacement spindles used with the cast steel axle
housings.
On the ductile iron axle housings, the spindle locking screw (part no. 4103–5010319685) has been relocated. Refer to
the illustration below:
Spindle Locking Screw Location

When an S58 or S65 axle housing is being replaced with an S582 or S652 housing, the “D” shaped spindle washer
(part no. 23QJ117B) must be replaced with a “tang” shaped washer (part no. 23QJ31).
With the change to the material composition of the axle housing assembly, welding of any type on the cast iron axle
housing must NOT be attempted in the field.

Issued by
Technical Service