Tiffin Motorhomes PowerGlide 2019 User manual

ALLEGRO BUS POWERGLIDE CHASSIS MANUAL
T
TI IF FF FI IN N M MO OT TO OR RH HO OM ME ES S, , I IN NC C. .
105 2nd Street NW  Red Bay, Alabama 35582 U.S.A.
2019 PowerGlide®
Owner’s Manual
WARNING: Breathing diesel engine exhaust exposes you to chemicals known to the
State of California to cause cancer and birth defects or other reproductive harm.
•Always start and operate the engine in a well-ventilated area.
•If in an enclosed area, vent the exhaust to the outside.
•Do not modify or tamper with the exhaust system.
•Do not idle the engine except as necessary.
For more information go to www.P65warnings.ca.gov/diesel.

ALLEGRO BUS POWERGLIDE CHASSIS MANUAL
TIFFIN MOTORHOMES, INC.
Allegro Bus Chassis Owner’s Manual
2019
 Tiffin Motorhomes, Inc.
105 2nd Street NW, Red Bay, AL 35582 U.S.A.
Telephone [phone] • Facsimile 256.356.8219
E-Mail: [e-mail]
Copyright © 2018 by Tiffin Motorhomes, Inc. -- all rights reserved
Printed in the United States of America: Sixth U.S. Printing: June 2018
[20180601]
DISCLAIMER
Many of the features and appliances described in this manual may or may not be reflected in the
actual motor home purchased, depending on the options and models selected by the motorhome
owner. All items, materials, instructions, and guidance described in this manual are as accurate
as possible at the time of printing. However, because of Tiffin Motorhomes’ ongoing and
dedicated commitment to excellence, improvement of Tiffin motorhomes is a continuing process.
Consequently, Tiffin Motorhomes reserves the right to make substitutions and improvements in
its makes and models of motorhomes without prior notification. Substitutions of comparable or
better materials, finishes, appliances, instrumentation, and instruction may be made at any time
it is deemed prudent to provide the customer with the best possible motorhome meeting the
customer’s requirements.

ii
Tiffin Allegro Bus - PowerGlide Chassis
Customer Support
256-356-0261
Monday-Friday
6 a.m. - 4:30 p.m. CST
If you should require chassis service, you should first contact your nearest Tiffin
Powerglide®Chassis service center. Use
https://tiffinmotorhomes.com/locate_dealer/map.php to find an authorized warranty
service facility. If for some reason this is not possible or if you would like to call the
manufacturers direct, you can contact them at the following telephone numbers:
TIFFIN POWERGLIDE CHASSIS
256-356-0261
(Please have your VIN# ready)
SAFE RIDE
(Nights and weekends)
1-877-276-0619
CUMMINS ENGINE COMPANY
1-800-CUMMINS (800-286-6467)
ALLISON TRANSMISSIONS
1-800-524-2303
MICHELIN TIRE
800-TIRE-HELP (800-847-3435)
Visit our website at www.tiffinmotorhomes.com

ALLEGRO BUS POWERGLIDE CHASSIS MANUAL
ii
Table of Contents
Chapter 1
Tire Care
Tire Care 1-2
Correct Tire Pressure 1-3
Chapter 2
Allison Transmission Operation
Driving Considerations 2-2
Fluid Level Check 2-3
Chapter 3
Brake System
Brake System 3-2
Compressed Air System 3-4
Air Dryer 3-6
Engine Compression Brake 3-7
Chapter 4
Cummins Engines
Engine specs and maint. 4-2
EPA Mandates 4-4
ATS Warning Lamps 4-5
DPF Maintenance 4-6
Aftertreatment Operation 4-6
Engine Indicator Lamps 4-8
Engine Starting 4-12
Cold-Weather Starting 4-13
Engine Braking (optional) 4-13
Cruise Control 4-14
Engine Shutdown 4-15
Diagnostic Fault Codes 4-15
Towing Hitch 4-16
Chapter 5
Scheduled Maintenance
Scheduled Maintenance Chart 5-2
Fluids 5-5
Lubrication Points 5-8
Maintenance Parts 5-13
Tiffin Assistance 5-15
Chapter 6
Pre-Trip Inspection
Pre-Trip Inspection 6-2

ALLEGRO BUS POWERGLIDE CHASSIS MANUAL
iii
Chapter 7
Instruments & Controls
Graphical Instrument Cluster
Operation Guide 7-2
Overview 7-5
Indicator Quick Reference 7-6
Gauge Quick Reference 7-8
Navigation 7-9
Indicators 7-10
Gauges 7-14
Selectable Display 7-18
Alarm Messages 7-23
Menu Map 7-28
Parts Gallery 7-31
Smart Wheel Steering Wheel 7-33
Chapter 8
Air Supply
Air Supply 8-2
Chapter 9
Tag Axle
Tag Axle Operation 9-2
Chapter 10
Warranty
Chassis Warranties 10-2
Chapter 11
Allegro Club
Allegro Club Information 11-2

TIRE CARE
1-1
TIRE CARE
Chapter
1

TIRE CARE
1-2
Tiffin Motorhomes: “Wherever you go…we go”
Tire Care
Maintaining the proper tire inflation pressure is the most important thing you can do to maximize the life of
your tires. An under-inflated tire can build up excessive heat that may go beyond the prescribed limits of
endurance of the rubber and the radial cords. Over-inflation will reduce the tire’s footprint on the road,
reducing the traction, braking capacity, and handling of your vehicle. An over-inflated tire will also cause a harsh
ride, uneven tire wear, and will be more susceptible to impact damage.
Keep in mind that the pressure rating on the side wall of your tire is the maximum pressure for that tire. This is
not necessarily the correct pressure for the tires when installed on your vehicle. Maintaining the correct tire
pressure for your vehicle’s loaded weight is extremely important and must be a part of regular vehicle maintenance.
TIRE CARE
•What is the most important component of tire care?
TIRE PRESSURE
oWhy?
Improved Ride
Improved Tire Wear
Improved Road Handling
Improved Braking

TIRE CARE
1-3
Correct Tire Pressure
•How to determine the correct pressure:
Weigh each wheel position
Set tire pressure according to chart
* This Chart Shows Cold Inflation Pressures
315/80 R22.5 LRL X LINE ENERGY Z COACH
Load per Wheel-end
22.5 X 9.00” Wheel
PSI=>
90
95
100
105
110
115
120
125
130
Max
Load per
Tire
KPA=>
620
660
690
720
760
790
830
860
900
Single LBS 13,340
13,880 14,380 14,880 15,220 15,840 16,540 17,380 18,180 9,090
Dual LBS
24,280 25,580 26,180 27,760 27,760 28,840 30,440 31,640 33,080 8,270
Single KG 6,060 6,300
6,520 6,740 6,900 7,180 7,500 7,880 8,250 4,125
Dual KG
11,000 11,600 11,880 12,280 12,600 13,080 13,800 14,360 15,000 3,750

TIRE CARE
1-4
To determine the correct air pressure for your tires, load your motor home as you would normally travel,
including water and fuel. Go to a truck scale as found at most major truck stops and weigh each wheel
position independently, with driver and passenger(s) in the vehicle as described in the Michelin Recreational
Vehicle Tire Guide (MWL43146 Rev. 03/12) to determine the correct air pressure for the weight on each
wheel position. Then use the charts in the guide and adjust the pressure accordingly when the tires are cool or
have not been driven for more than one mile. You may call 1-800-847-3435 for a copy of the Michelin
Recreational Vehicle Tire Guide , or visit: https://www.michelintruck.com/reference-materials/manuals-
bulletins-and-warranties/load-and-inflation-tables/#/
NOTE: Never reduce the air pressure in a hot tire.
REMEMBER: For control of your RV, it is critical that the tire pressure be the same on both sides of the axle.
Emissions and Fuel Efficiency
Compliance
Your chassis was designed, and built, with components including, but not limited to, low rolling resistance tires
specifically designed and manufactured to exacting standards for regulatory fuel efficiency and greenhouse gas
emissions compliance. The vehicle owner is responsible for being sure these components are replaced with
the same or equivalent components that maintain compliance with federal and local regulations.
For help with determining tires that are the same or equal in regards to rolling resistance for maintaining
compliance with the regulatory standards, please contact Michelin at 1-800-947-3435.

ALLISON TRANSMISSION OPERATION
2-1
Allison Transmission Operation
Chapter
2

ALLISON TRANSMISSION OPERATION
2-2
Driving Conditions
•Normal driving – best fuel economy
oSelect “D” and “Mode On”
•Performance
o“Mode Off”
oFor mountain driving, select lower gears to maintain 2000+ engine RPM
•Hill climbing on hot days
oKeep RPMs high to cool engine
Driving Tips with the Allison 3000MH or 4000MH Transmission:
The points at which shifts occur depend upon predetermined speeds and other operating conditions. A
transmission “shift calibration” includes several sets of shift points used according to current or anticipated
operating conditions, such as engine or transmission fluid temperature. You can change shift schedules using
the MODE button.
The transmission control module (TCM) includes the capacity for two separate and distinct shift calibrations,
one for use in “Primary Mode” of operation and one in “Secondary Mode.”
Primary – This shift schedule is typically used for all normal vehicle operations.
Secondary – This is an alternate shift schedule that the TCM uses upon request. This is operator-
controlled using the MODE button.
When you are driving under normal road conditions, the DRIVE mode is recommended for the best
performance and fuel economy. The MODE switch should be set to ON for economy mode, but MODE off
should be used when climbing hills and when extra performance is required.
The display screen on the shift control pad will indicate the highest selected gear for the transmission. When
mountainous or up-and-down terrain conditions are encountered, you should manually select a lower gear,
preferably lower than 5th gear. This can be done at any road speed by pressing the down arrow repeatedly until
the desired gear is indicated in the window of the shifter pad. When your road speed decreases to a safe point,
the transmission will downshift at a higher RPM than normal. This will decrease the use of overdrive while
pulling hills, which can result in excessive heat build-up in the transmission, and keeps the engine operating at
peak horse power and performance.
When ascending a grade, maintain engine speed to within 400-500 RPM of governed engine speed. Governed
speed will be 2200 RPM on the Cummins ISL engine model. Road speed may decrease, but the engine will be
at its peak in the power curve.
It is especially pertinent to monitor your water temperature gauge when climbing steep grades. Keep in mind
that it is not uncommon for the temperature to increase, especially in hot weather. If the gauge reaches the end

ALLISON TRANSMISSION OPERATION
2-3
zone or if the temperature warning light on the gauge panel should come on, reduce your road speed, shift to
the next lower gear and keep your tachometer within 500 RPM of engine governed speed. In many cases this
will stabilize the water temperature. If the temperature gauge continues to rise, pull to the side of the road and
shift the transmission into neutral. Bring the engine RPM to 1,700—2,000 RPM until the temperature drops
down into the normal range. This should occur in a relatively short period of time. If the temperature gauge does
not begin to drop, stays in the red zone, or continues to rise, shut down the engine and allow it to cool. After the
engine is allowed to cool check the fluid level in the reservoir and add coolant if needed.
A good “rule of thumb” for descending grades is to never use a higher gear than was used to climb the same
or similar grade. Try to keep the engine within 500 RPM of governed speed. This will give the best engine
braking and reduce the need to use the service brakes. Select a gear that will keep you at a safe speed with
minimal brake application. Never ride your brakes when descending a grade since excessive brake heat will
build up and your brakes could fade, leaving you with little or no braking power.
Your vehicle is equipped with an engine brake. The engine brake will assist in slowing your vehicle on a
downhill grade. With the engine brake switch in the ON position, release the accelerator and depress the
service brake to activate the engine brake. When the engine brake is activated the transmission will pre-select a
lower gear to aid in braking. This is indicated by a “2” in the left hand pane of the transmission shift selector.
The transmission will begin to down-shift as soon as the road and engine speed will safely allow. This will
produce a slowing effect and will remain engaged until either the exhaust brake switch is turned off, the
accelerator is pressed, or the engine speed drops to 800 RPM. If your initial speed is high, you may have to
step on the brake to slow the vehicle before the transmission will down-shift from 6th gear to 5th gear. This is
normal.
Always select (N) neutral on the transmission shift pad prior to turning off the vehicle engine.
Fluid Level Check
Use the transmission shift pad for best results in checking the transmission fluid level. The transmission will
not reach operating temperature until the coach has been driven for at least 15 miles. Therefore, it may be best
to check transmission fluid level at the end of your driving day.
Transmissions do not consume fluid. If your transmission shows to be low of fluid, it should be inspected for
leaks.

ALLISON TRANSMISSION OPERATION
2-4
Check the transmission fluid level with the following steps:
Conditions that must be met
•Be sure transmission is at operating temperature (104° to 220° F)
•Vehicle is parked on level ground with the parking brake is set
•Transmission in neutral and engine at idle
•Wait until vehicle has been stationary for two minutes
•Simultaneously press the up and down arrow keys
•Correct fluid level will be indicated by
•Low fluid level will be indicated by
•High fluid level will be indicated by
If conditions are not met one of the following messages will be displayed
•Oil temp too low
•Not in neutral
•Not stationary for two minutes
•Engine not at idle
TRANS OIL
LEVEL OK
TRANS OIL
2QT LOW
TRANS OIL
3QT HI
OIL TEMP
TOO LO
MUST BE IN
NEUTRAL
SETTLING
:62
ENG RPM
TOO HI

BRAKE SYSTEM
3-1
Brake System
Chapter
3

BRAKE SYSTEM
3-2
Brake System
Figure 3-1: Rear Brakes
Front brakes are 17” air applied disc
Rear brakes (Figure 3-1) double as parking brake
-Park brakes are spring applied – air released
-Two large 16.5 x 7” drum brakes
-Park brake remains applied even if air pressure is lost
If air pressure is lost
-A buzzer and warning lamp will alert you
Chassis is equipped with automatic slack adjusters (Figure 3-2)
-No brake adjustment required
Figure 3-2: Automatic Slack Adjuster
The rear brakes on the PowerGlide chassis are also used as the parking brakes. This provides you the holding
power of two large drum brakes to prevent your coach from rolling, even when fully loaded on a 20% grade.
A decrease in air pressure while driving will not cause an immediate loss of brakes. If a significant leak develops
in the air system, at approximately 60 PSI you will be alerted by a lamp on the instrument panel, and by an
audible alarm. As you apply the brakes, the air supply holding the park brakes in the released position will
gradually be depleted. When system pressure drops to approximately 40 PSI the rear brakes will set. This allows
you sufficient time to pull over to the side of the road.

BRAKE SYSTEM
3-3
NOTE: The rear brakes have dual chambers – one for the service brakes and one for the park brake. The
service brakes are air applied and spring released. The park brake is spring applied and air released.
The brake system is equipped with automatic slack adjusters that avoid the need to manually adjust your brakes.
Each time you step on the brake pedal, if adjustment is needed, the adjusters will take up the slack.

BRAKE SYSTEM
3-4
Compressed Air System
36’ and 40’ Bus Non-Tag Tank Drains

BRAKE SYSTEM
3-5
43' Bus Tag Tank Drains

BRAKE SYSTEM
3-6
Compressed Air System
The compressed air system is comprised of multi-air storage tanks. The primary tank stores and supplies
air for the rear brakes, the secondary tank stores and supplies air for the front brakes.
When air is compressed it becomes hot. As it cools, condensed moisture forms in the system. The air system is
equipped with an air dryer to remove most of this moisture. The dryer has an automatic moisture ejector that
releases the trapped moisture back into the atmosphere. However, some moisture will form in the system
beyond the dryer, and make its way into the storage tanks. As moisture collects in the primary and secondary
tanks, it displaces the area needed for air storage, thus requiring that the tanks be drained periodically.
The air system is equipped with air tank drains conveniently located in the compartment with the DEF tank.
Each drain is attached to a different tank. These drains should be opened regularly for a few seconds to
remove any moisture trapped in the tanks.
Air Dryer
The Tiffin PowerGlide chassis air brake system features a Haldex Purest air
dryer (Figure 3-3), which removes the condensed moisture from
compressed air. The air dryer is equipped with a desiccant cartridge that
needs to be changed every 36 months. The dryer is located on the driver's
side (LH) frame rail (behind the rear axle).
Figure 3-3: Haldex Purest Air Dryer
Warning
Air tanks should be bled of all pressure any time you perform work on the air system.

BRAKE SYSTEM
3-7
Engine Compression Brake
Figure 3-4: Compression Brake
The engine compression brake (Figure 3-4):
Improves braking power
Reduces the chance of overheating brakes on steep grades
Works in conjunction with the transmission to help slow the vehicle
Has two stages (low and high) for varying terrain
All brakes will build up heat when being used due to friction – this is normal. However, excessive use of the
brakes when descending a grade can result in excessive heat and can cause “brake fade” or a loss of braking
power, even with disc brakes. The proper way to use your brakes is to go slowly enough that a fairly light,
occasional use of the brakes will keep your speed from increasing.
NOTE: DO NOT maintain continual brake pedal pressure when descending a hill with any type of brake
system.
Rather, down-shift the transmission to slow the vehicle and make light, intermittent brake applications to
control downhill speeds. By utilizing the transmission gears and compression brake, continual use of the brakes
will not be necessary. When using the transmission’s lower gears to slow the vehicle on hills, be careful not to
exceed the governed speed of your engine. If engine-governed speed is exceeded, the transmission will shift up
to the next range, rapidly increasing the speed of your vehicle. If you find that you are continually using the
brakes to maintain a safe speed and to keep the RPM within this range, slow the vehicle down even further and
shift the transmission to a lower gear.
Warning
DO NOT USE the compression brake on wet roads, hazardous, or slippery conditions.
As with any motorized vehicle, practice safety when on the road.