KitchenAid K45SS, KSM75, KSM90, KSM103, KSM110 User Manual

SERVICE MANUAL for

KITCHENAID

STAND MIXER

Models K45SS KSM75

KSM90 KSM103
KSM110 KSM150
KSM151 K5SS
KSM5 KSM50P
KSMC50 KPM5
KPM50 KP50P

Printed in U.S.A. September, 2005 LIT4177310-C

KITCHENAID

Stand Mixer Service Manual Lit4177310-C 2005 KITCHENAID

Safety Guidelines

This Service Manual is written for the Professional Service Technician who has familiarity with the

KitchenAid Stand Mixer. The following Safety Guidelines should be adhered to when servicing this product.

SERVICE ENVIRONMENT

•The workplace will be dry and sanitary at all times and all units should be inspected for cleanliness before
any work is started.

•Visually inspect the unit requiring service in a well luminated area.

•A mild, non-abrasive dishwashing soap solution and clean towel can be used to wash any unit requiring
attention.

•The hands of the service technician should be clean at all times during service procedure.

ELECTRICAL CONSIDERATIONS

•The workplace for the stand mixer will have properly grounded AC outlets that adhere to all Local
Electrical Codes that are applicable at the time of repair.

•The Stand Mixer Power Cord should always be inspected first before testing the mixer operation.
Do NOT run the mixer if the Power Cord is damaged -- replace it.

•All disassembly and assembly procedures discussed in this manual should be conducted with the unit
disconnected from the AC mains.

•Do NOT leave the unit unattended while running the mixer for speed range and bowl clearance checks.
Always unplug the unit immediately after concluding these tests.

Technician

•The Service Technician should wear Protective Eyewear at all times when conducting a repair on the Stand
Mixer.

•Loose fitting sweaters, shirts sleeves or bracelets should NOT be worn while servicing the Stand Mixer.

SAFETY

KITCHENAID

Stand Mixer Service Manual Lit4177310-C 2005 KITCHENAID

INDEX: Stand Mixer Repair Manual

K45SS KSM75 KSM90 KSM103 KSM110 KSM150 KSM151
K5SS KSM5 KSM50P KSMC50 KPM5 KPM50 KP50P

SECTION SUBJECT PAGE

- General Information 1
1 Disassembly of Gearcase and Planetary 2
2 Disassembly of Motor and Control Unit 6
3 Repairs to Motor and Control Unit 11
4 Repairs to Gearcase and Planetary 16
5 Repairs to Pedestal 21
6 Adjustment to Control Unit 22
7 Repairs to Bowl Lift Assembly 26
8 Troubleshooting the Bowl Lift Assembly 30

APPENDIX SUBJECT

A Tools Required for Stand Mixer Service
B Problem Solving Quick Reference Guide
C Domestic Model Wiring Diagram
D International Model Wiring Diagram - RF Filter
E International Model Wiring Diagram - Bowl Interlock RF Filter
F Stand Mixer Serial Number Codes

Introduction

All KitchenAid Stand Mixers are well designed and carefully built. Normally they

will give continual use year after year without service attention.

Careful records have been maintained over a period of years to determine and

correct, through improved design, any troubles that might possibly develop.

An effort has been made in preparation of this manual to cover them all.

INDEX

KITCHENAID

Stand Mixer Service Manual LIT4177310-C 2005 KitchenAid

Heating

GENERAL INFORMATION

Normal Performance

The KitchenAid Stand Mixer is powered with a
universal motor which will operate on 50 or 60 hertz,
alternating current only.

The Voltage of the power supply should be within 10
volts either way of the voltage stamped on the mixer
trimband and nameplate.

A mixer in good running condition will start turning
slowly when the switch lever is moved from the “OFF”
position to the “STIR” position.

As the switch lever is moved to successively higher
positions, the speed of the beater increases until the #10
speed is reached.

At stir position, the planetary should turn at
approximately 60 RPM; at the #10 position all models
turn at approximately 255 RPM, with the exception of
K45SS models built before May 6th, 2002 (WM19),
which turn at approximately 280 RPM.

KITCHENAID STAND MIXER RPM

SPEED *K45SS OTHER MODELS

STIR 60 RPM 60 RPM

#10 255 RPM 255 RPM

Prior to May 6th, 2002,

#10 280 RPM
*Note: All models have similar RPM, except K45SS

th

units built before May 6
in the #10 position.

The mixer will run quietly in the lower speed range;
however, some noise can be expected on the higher speed
settings due to hum of gears and the motor.

When the mixer is first turned to the stir position, there
may be a slight clattering, irregular noise. This noise will
disappear as the lubrication in the gearcase warms up.

The switch lever should move freely with the “feel” of
definite positions for speed numbers stir, 2, 4, 6, 8 and 10.
Speed numbers 3, 5, 7 and 9 do not have definite notches.

, 2002, which run at 280 RPM

Power

A mixer will have full power on all speed settings. To
check for full power, carefully hold the planetary with
one hand and move the switch lever on and off with the
other hand.

At the stir position, it should not be possible to stall the
planetary except by a very great effort; nor should the
planetary slow down noticeably when the retarding
pressure is applied.

Under normal conditions, the mixer will not show
any tendency to heat because of the built-in
ventilating system in the motor.

Under heavy loads with extended mixing time
periods, the head may heat up to the point of being

uncomfortable to touch

.

Speed Control

The speed control of the mixer is attained through
the use of a governor assembly mounted at the rear
of the control plate assembly.

The electrical circuit is made and broken by the action

of the fly ball governor revolving against the control

plate.

When the switch lever is moved to an ON position,

the position of the control plate with respect to the

governor is changed by the action of the switch lever.

Thus, when the control plate is set close to the
governor, a relatively low speed of the motor causes the
governor to make or break the mixer’s electrical circuit
through the control plate.

When the control plate is set farther away, a greater
motor speed is required before the governor starts
breaking the circuit.

The action of the governor is such that the speed of the
motor will remain constant for a given setting of the
control plate within certain loads.

After certain loads have been exceeded, the speed of the
motor will drop to meet the torque requirements of the
given load.

Speed is controlled by the governor and the control
plate in conjunction with the phase control.

TRIAC RMS VOLTAGE

BOTH CONTACTS OPEN - 40 VOLTS
ONE CONTACT OPEN - 80 VOLTS
BOTH CONTACTS CLOSED - FULL VOLTAGE
NOTE: The triac regulates the power the motor sees

depending on control board contacts.

A device called a triac is a part of the phase control
circuit.

This device determines the amount of power the motor
sees dependent upon the condition of the control board
contacts.

If both contacts are open, about 40 volts RMS is
applied to the motor and about 80 volts is applied when
either contact is closed and the other is open.

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Stand Mixer Service Manual LIT4177310-C 2005 KitchenAid

When both contacts are closed, the triac is full
on; consequently, full power is applied to the
motor. In this way, the speed is controlled.

If the mixer motor begins to run too fast for a
particular speed setting, one or both contacts
open, which cuts back on the voltage the motor
sees, thus slowing it up.

If the motor operation becomes too slow, one or
both contacts will close, applying the needed
voltage to the motor to sufficiently increase
motor speed.

This is always accomplished through the triac.

The control plate contacts control the triac, and
in turn, controls the amount of power supplied to
the motor.

BEATER

The beater should fit freely on the beater shaft
located in the planetary.

Power is transmitted from the motor to the
center-bevel gear assembly by means of the
worm gear.

The center-bevel gear assembly engages the
beater pinion, located in the planetary, to turn the
beater shaft.

The attachment hub bevel gear also meshes with
the center-bevel gear assembly to transmit power
when various attachments are being used.

LUBRICATION

Under normal service conditions, the mixer will
not require lubrication for many years.

The gear case is lubricated with an ample supply
of Benalene 930-2 grease (6 fluid ounces), which
lubricates all the gears and shafts.

SECTION 1

DISASSEMBLY OF THE GEARCASE AND

PLANETARY

A. All solid state KitchenAid mixers have the

same motor and control parts and the gears in the
gearcase are alike, with one exception: “K45SS
units built prior to May 6th, 2002.”

Planetary parts are all the same, except that some

early production K5SS had a lead weight.

Gearing and motor instructions are for both tilt
head and bowl lift machines and any differences
will be pointed out.

BOWL LIFT

KSMC50,KPM5, KPM50, KP50. The bowl is

raised and lowered into position.

TILT HEAD
KSM90, KSM103, KSM110, KSM150, KSM151,
KSM152. The mixer head is tilted up and down
into position.

Bowl, column, base and bowl lift details are

covered separately in section 7.
B. Before repairs are attempted on any KitchenAid
mixer, a wattmeter test should be made. To make
the test, set the wattmeter to the proper voltage.

Next, plug the cord from the mixer into the

wattmeter. Turn on the current and run the mixer.

- Models K5SS,KSM5,KSM50,

- Models K45SS, KSM45, KSM75,

GEARCASE LUBRICATION

All KitchenAid Stand Mixer Gearcases are
lubricated with 6 Fluid Ounces of:
BENALENE 930-2 GREASE

NOTE: Gearcases lubricated with this grease

will not require lubrication for years.

The motor bearing and the beater shaft bearing

are oil impregnated.

The rear motor bearing has a felt washer which

has been presoaked in oil.

The front motor bearing in the mixer housing is

a ball bearing.

(OR EQUIVALENT)

KitchenAid stand mixer shown with a digital wattmeter

If the wattmeter shows up to 135 watts, going from

stir to #10 speed, the mixer is in good condition.

If the wattmeter reading is 175 to 400 watts, there

is a problem.

High wattage mixer readings indicate either

electrical or mechanical problems.

Check first for bearing/gear drag, then for
motor/brush problems.
CAUTION: Always remove power cord from
electrical outlet before servicing any part of the
mixer.

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Stand Mixer Service Manual LIT4177310-C 2005 KitchenAid

C. Note: remove the bowl and any attachments

before disassembly of unit.

Remove the #6-32x3/8” (tapered head) screw

from the end cover (Fig. 1).

FIG # 1

Fig. 1 The end cover is removed by removing the
tapered head endcover screw.

Remove the two #6-32x3/16” screws that hold the
trimband to the gearcase-motor housing (Fig. 2).
With the screws removed, take the trimband off and
set aside.

Fig. 3 Loosen the hinge pi n se ts crew to remove the
pedestal from the bottomcover

Using a drift punch and hammer, drive out the
hinge pin (Fig. 4) and lift the pedestal off the
gearcase-bottom cover.

.

Fig. 2 The trimband can be removed after removing the
trimband screws.

D. To save the paint, lay the unit in a padded cradle

or on a cloth pad.

To remove the pedestal from the gearcase-bottom

cover, turn the unit upside down in a padded cradle.

Loosen the set screw with a screwdriver (Fig. 3)

Fig. 4 A drift punch and hammer is used to drive out the
hinge pin.

E. To remove the planetary, first remove the drip

ring . Use a screwdriver on the upper edge of the
drip ring and gently tap the screwdriver to remove
the drip ring (Fig. 5).

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Stand Mixer Service Manual LIT4177310-C 2005 KitchenAid

F. Remove the power cord from the bottom cover

by sliding the molded strain relief out of the slot in
the bottom cover (Fig. 8).

Fig. 5 The Drip Cup fits tightly and must be started off by

tapping it.

With a 5/32” drift punch, remove t he groove pin
that holds the planetary to the vertical center shaft
(Fig. 6).

Fig. 8 Pull back on the molded strain relief to remove
the power cord from the slot in the bottom cover.

Fig. 6 Removal of the groove pin that holds the
planetary to the vertical center shaft

With the pin out, the planetary can be removed
from the center shaft. Using two (2) screwdrivers,
pry the planetary up and off the shaft (Fig. 7).

To remove the power cord with the Heyco strain
relief used on older models, use a pair of pliers to
squeeze the strain relief while pulling up (Fig. 9).
Reverse this procedure to reinstall it.

Fig. 9 Removal of Heyco strain relief using pliers.

G. To remove the bottom cover from the gearcase-

motor housing, unscrew the five (5) #10-24 special
screws (Fig. 10). These screws hold the internal
gear into the bottom cover.

Next remove the four (4) filister head screws from

the bottom cover (Fig. 11).

Fig. 7 Use two screwdrivers to pry the planetary off the
shaft.

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Stand Mixer Service Manual LIT4177310-C 2005 KitchenAid

Fig. 10 Removal of the 5 special screws holding the
internal gear in the bottom cover.

Fig. 11 The bottom cover is removed after removing the

four #10-24 filister head screws.

To remove the bottom cover from the gearcase­motor housing, insert a drift punch through the hole
in the center shaft and lift, while using a screwdriver
to break the bottom cover loose.

Use the slots in the side of the gearcase to do
this (Fig. 12).

Do NOT
as this may prevent the gasket from sealing properly
upon reassembly.

The transmission gears will come out with the
bottom cover. Be careful not to allow any grease to
fall into the motor area of the housing.

pry in the area of the transmission gasket,

Fig. 12 While lifting up on the center shaft, use a screw

driver to gently pry the bottom cover from the
housing.

H. Remove the attachment hub bevel gear from

the gearcase-motor housing.

This gear is removed by simply pulling it out of
the attachment hub (Fig. 13). The gear will clear
the worm of the motor’s armature shaft and
should be easy to remove.

Note: For clarity, the pictures in this manual have

no grease shown in the gearcase. Normally the
gearcase has 6 oz. of grease surrounding the gears.

Fig. 13 The attachment hub bevel gear being removed
from the mixer attachment hub bearing.

I. Clean out the gearcase and remove as much of

the grease as possible.

The gearcase may be thoroughly cleaned when
the motor has been removed.

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Stand Mixer Service Manual LIT4177310-C 2005 KitchenAid

SECTION 2

DISASSEMBLY OF STAND MIXER MOTOR

AND CONTROL UNIT

Note: All service operations discussed

here should be performed with the mixer
disconnected from the A. C. mains.

A. Start the disassembly of the control unit by
removing the cord flag terminals from the control
board and the ground wire from the bearing bracket
(Fig. 14).

Remove the end seal and disconnect the phase
control flag terminals from the control board

(Fig. 16).

Fig. 16 After removing the end seal, remove the
phase control flag terminals.

Unhook the control board spring at the bottom of

the control board (Fig. 17).

Fig. 14 Removal of the cord flag terminals and
cord ground wire.

Remove the motor stator flag terminals from the

control board ( Fig. 15).

Fig. 15 The removal of the motor stator flag
terminals from the control board.

Fig. 17 Unhook the control board spring.

Unlock the two lock nuts on the control board a
unscrew the two adjusting screws.

The mixer control board can now be removed a
set aside for later evaluation (Fig. 18 ).

nd

nd

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Stand Mixer Service Manual LIT4177310-C 2005 KitchenAid

Fig. 18 Mixer housing with end seal and
control board removed.

B. The phase control can now be disassembled from

the bearing bracket, if necessary, by unscrewing the
#4-40 x 1/4” pan head screw (Figs. 19 & 20).

Fig. 20 Phase control or (triac) shown
removed in lower center.

Fig. 21 Needle nose plier used to pry governor off
the motor shaft.

Fig. 19 Removal of the phase control (Triac)
from the bearing bracket.

C. With a pair of needle nose pliers, carefully pry

off the governor assembly. (Fig. 21) Do NOT
bend.

Remove the governor drive pin and lay it aside so

it will not be lost (Fig. 22).

Fig. 22 Governor shown removed from the shaft
of the motor.

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Stand Mixer Service Manual LIT4177310-C 2005 KitchenAid

D. To remove the speed control link and cam

assembly, take out the pivot screw and tension
washer (Fig. 24).

Flat Spring

Fig. 25 Removing the speed control spring, flat spring and
the speed control link assembly.

E. Unscrew and remove the two #10-24 nuts

(Fig. 26).

Fig. 24 The pivot screw and tension washer are removed
with a phillips screwdriver.

Before removing the speed control link and cam
assembly, remove the control board spring from the
link.

The flat spring is removed as you remove the speed

control link assembly.

The speed control link and cam assembly can be
removed by pulling it out of the gearcase-motor
housing (Fig. 25).

Fig. 26 Two 10-24 nuts are removed from the
bearing bracket.

Remove the bearing bracket (Fig. 27).
Now remove the motor stud sleeve from the stator

stud (Fig. 28).

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Stand Mixer Service Manual LIT4177310-C 2005 KitchenAid

Fig. 27 Bearing bracket being removed after two #10-24
nuts have been removed.

Fig. 28 The motor stud sleeve is shown being removed after
bearing bracket removal.

F. Unscrew the two brush holder screw caps and

remove the brushes and springs (Fig. 29).

Viewing from the rear, mark the brushes right and

Fig. 29 the brush holder caps are loosened to access
brushes for removal. Make sure to mark orientation.

G. The armature can now be removed.

With the attachment hub bevel gear removed,
insert a drift punch through the attachment hub
opening and gently tap the armature back through
the stator using a block of wood to protect the
shaft (Fig. 30).

left, and also the top of the brush, just as it was
removed from the motor.

Fig. 30 A block of wood is used to protect the motor
shaft when removing the armature.

Remove the worm end bearing washer and the
fan end spacer washer.

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Stand Mixer Service Manual LIT4177310-C 2005 KitchenAid

H. Pull the two wires from the rear of the stator

through the slot in the gearcase-motor housing so
they are inside the gearcase-motor housing and
sticking out the back (Fig. 31).

Stator Wires

Fig. 31 Wire orientation inside the gearcase-motor housing

Using long pliers, pull the brush slips from the
stator out of the brush holders. Note orientation of
stator clip in brush holder.

Remove the two #10-24 nuts from the stator studs

and carefully set aside for use during reassembly.

Unscrew one stator stud and pull out the stator

(Fig. 32).

I. To remove the brush holder , it will be
necessary to remove the other stator stud.

Under the stator studs are #10-24x1/4 cup point
screws. To remove the set screws, use a 3/32”
Allen wrench; older models may use a flat
screwdriver (Fig. 33).

Fig. 33 Removing the brush holder set screws with a

allen wrench.

Unscrew the set screws a few turns and (from
inside the housing) push the brush holder out by
hand. Note the orientation of the brush insert
inside the brush holder.

Fig. 32 The stator is shown being removed from the motor
housing.

To pull the stator out, reach into the motor housing

and grasp the stator and pull it out. Caution: Do

not nick or damage the copper coil wires on
the motor.

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