Tiffin Motorhomes PowerGlide 2020 User manual

ALLEGRO RED-340 POWERGLIDE CHASSIS MANUAL
TIFFIN MOTORHOMES, INC.
105 2nd Street NW Red Bay, Alabama 35582 U.S.A.
2020PowerGlide®
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 RED-340 POWERGLIDE CHASSIS MANUAL
TIFFIN MOTORHOMES, INC.
Red 340 Chassis Owner’s Manual
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 © 2019 by Tiffin Motorhomes, Inc. -- all rights reserved
Printed in the United States of America: Sixth U.S. Printing: March, 2019
[20190301]
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
Allegro Red 340 Tiffin 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. 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)
COACH-NET
(Nights and weekends)
1-866-590-5937
CUMMINS ENGINE COMPANY
1-800-DIESELS (800-343-7357)
ALLISON TRANSMISSIONS
1-800-524-2303
MICHELIN TIRE
800-TIRE-HELP (800-847-3435)
Visit our website at www.tiffinmotorhomes.com

ALLEGRO RED-340 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 2-4
Chapter 3
Brake System
Brake System 3-2
Compressed Air System 3-4
Air Dryer 3-6
Engine Brake 3-7
Chapter 4
Cummins Engine
EPA Mandates 4-3
ATS Warning Lamps 4-4
DPF Maintenance 4-4
Aftertreatment Operation 4-5
Engine Indicator Lamps 4-7
Engine Starting 4-11
Cold-Weather Starting 4-12
Engine Braking (optional) 4-12
Cruise Control 4-13
Engine Shutdown 4-14
Diagnostic Fault Codes 4-15
Towing Hitch 4-15
Chapter 5
Scheduled Maintenance
Scheduled Maintenance Chart 5-2
Fluids 5-5
Lubrication Points 5-8
Maintenance Parts 5-13
Tiffin Assistance 5-14
Chapter 6
Pre-Trip Inspection
Pre-Trip Inspection 6-2
Chapter 7
Instruments & Controls
Tiffin Instrument Panel 7-2
Driver’s Information Center 7-5
Trip Reset and Average Fuel Economy 7-9
Modes of Operation 7-10
Chapter 8
Air Supply
Air Supply 8-2

ALLEGRO RED-340 POWERGLIDE CHASSIS MANUAL
iii
Chapter 9
Warranty
Chassis Warranties 10-2
Chapter 10
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
PSI=>
70
75
80
85
90
95
100
105
110
Max
Load per
Tire
KPA=>
480
520
550
590
620
660
690
720
760
Single LBS 3,875 4,070 4,300 4,440 4,620 4,805 4,975 5,150 5,205 5,205
Dual LBS 7,050 7410 7,720 8,080 8,410 8,820 9,050 9,370 9,610 4,805
Single KG 1,760 1,850 1,950 2,010 2,100 2,180 2,260 2,340 2,360 2,360
Dual KG 3,200 3,360 3,500 3,660 3,820 4,000 4,100 4,260 4,360 2,180
255/80 R22.5 LRG - XRV
Load per Wheel-end
22.5 X 9.00” Wheel

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 .
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
Operation
The Allegro Red 340 with the Powerglide Chassis is equipped with an Allison 2500MH transmission.
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 2800 RPM on the Cummins ISB 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 225°F
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, or if the stop engine light comes on,
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 ether 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.

ALLISON TRANSMISSION OPERATION
2-3
Mode Button
The mode button is located on the keypad pushbutton shift selector. The mode button can
be pressed at any time after engine start to activate the alternate shift schedule. There are two shift
schedules, a primary and a secondary.
The primary shift schedule is normally used each time the vehicle is started and is specified
in such a way to accommodate “NORMAL” vehicle operation. This shift schedule is also known
as “PERFORMANCE” mode.
The secondary shift schedule is an alternate shift schedule that the TCM only uses upon
request. This shift schedule is also known as “ECONOMY” mode.
“ECONOMY” mode will allow the transmission to make shift changes at a lower engine
RPM, thus making it possible to get better fuel mileage.Factors such as terrain, driving habits,
vehicle weight and towing will still have an impact on mileage.
Fluid Level Check
Use the transmission dipstick 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.
The dipstick is marked with temperature bands for a COLD and HOT fluid level check. The fluid check
marked COLD is designed to allow the fluid level to be checked from 61-140°F (16-60°C). The fluid check
marked HOT is designed to allow the fluid level to be checked form 160-220°F (71-104°C).
Check the transmission fluid level with the following steps (HOT CHECK PROCEDURE):
Conditions that must be met for checking transmission fluid with the dipstick:
•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 park brake applied
•Engine is at low idle
•Wait until vehicle has been stationary for two minutes
•With the engine running, remove the dipstick from the tube and wipe the dipstick clean
•Insert the dipstick into the tube and remove. Check the fluid level reading. Repeat the check
procedure to verify the reading.

ALLISON TRANSMISSION OPERATION
2-4

BRAKE SYSTEM
3-1
Brake System
Chapter
3

BRAKE SYSTEM
3-2
Brake System
Figure 3-1: Rear Brakes
•Front brakes are air applied disc
•Rear brakes (Figure 3-1) double as parking brake
-Park brakes are spring applied – air released
-Two large 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

BRAKE SYSTEM
3-5