The document discusses timing belt and auxiliary drive systems used in modern automotive engines. It provides an overview of timing belt and chain systems, explaining the components and operation of manual and automatic timing belt tensioners. It also discusses the multi-V belt used to drive multiple engine accessories and the importance of the cooling system, specifically the water pump. The document focuses on technology and material changes that have increased the performance and lifespan of modern timing belt and auxiliary drive components.
2. The crankshaft drives the camshaft(s) and actuates the valves via a belt or a
chain. Due to its advantages compared with those of a chain, namely reduced
space, as well as lighter and quieter running, the timing belt is widely used by
many car manufacturers.
Belt
tensioner unit
Idler pulley
Water
pump pulley
Crankshaft
Camshaft pulley
Timing belt
Injection
pump pulley
In today’s modern automotive engines, there has been a quiet revolution. The
need to run more auxiliary equipment such as water pumps or injection pumps,
combined with efficiency demands and noise reduction, has caused new timing
belt and tensioner systems to be developed.
At first, tensioners were of a fixed nature, usually of metal design. They were
simple to install: just set tension and tighten. Today, tensioners more likely
include an internal spring or external damper, and non-metallic components
are becoming more common. This illustration provides an overview of a modern
timing belt and tensioner system.
Engine-front wheel drive
Technical overview
3. Belt tensioner unit (TBT)
with an eccentric adjustment
Automatic TBT with a built-in
spring and friction system.
Timing belt tensioner (TBT) with rear plate
Automatic TBT
Belt tensioner unit (TBT)
The belt tensioner unit sets the right tension and provides guidance for the belt.
The adjustment of tension during mounting is achieved by means of an eccentric
or by means of a spring acting against a rear plate.
The automatic belt tensioner unit, with its built-in spring and friction system,
maintains a constant tension of the belt while the engine is running.
Main designs currently used are shown here:
Idler p
The idler
Main des
Timing
Timing b
greater e
Stable, h
Belt te
SKF belt
of-the-a
SKF in th
world’s a
quality a
the SKF
Timing
Tensile
aramid c
Material
reliability
Facing—
the tooth
frictional
4. Idler pulley
The idler pulley is fixed and allows the belt to be correctly wound around the driven component.
Main designs currently used are shown here:
Timing belt
Timing belts offer numerous advantages over chain and gear drives:
greater efficiency, reduced weight, quieter operation and fuel savings.
Stable, high tensile strength synthetic cords resist shrinking and stretching.
Belt tensioner pulley (TBP)
SKF belt tensioner pulleys for timing system are based on state-
of-the-art technology. The years of experience accumulated by
SKF in the design and supply of belt tensioner pulleys to the
world’s automotive manufacturers provides assurance of high
quality and performance of each belt tensioner unit included in
the SKF product range.
Idler pulley Idler pulley with rear plate
TBP with a rear plate
Timing belt
Rubber backing
Tensile members
Rubber tooth
Tooth facing
Timing belt construction
Tensile cords—High tensile strength fiberglass or
aramid cords resist stretching and shrinking.
Material—Durability, performance and
reliability in tough engine environments.
Facing—Wear resistant fabric protects
the tooth surface and keeps
frictional loss at a minimum.
5. How to use this catalog
1
This catalog has been divided into three sections: Applications, Information and Reference
1.) Refer to the table of contents for page number of section that is desired.
2.) How to use timing belt kit application section
Simply locate Manufacturer (manufacturer's are located in alphabetical order-refer to manufacturers index) and
model, locate year and message, locate your application information and once application has been found,
find the SKF kit number. (See below)
3.) Included for your information are: Engine drive system-overview, kit contents, installation information and frequently
asked questions.
4) For your reference included are: belt specifications, troubleshooting and failure analysis, good practices and helpful hints and a
kit reference buyer's guide.
Note: Part numbers with WP suffix (ex: TBK221WP) indicate kit contains a premium water pump plus camshaft and timing cover
seals along with belt(s), tensioners, idlers and detailed instruction sheets. (See kit product box image below on right side)
Part number with P suffix (ex: TBK147P) indicate kit contains camshaft and timing cover seals plus belt(s), tensioners, idlers
and detailed instruction sheets. (See kit product box image below on left side)
Honda Truck Passport, Ridgeline
Engine
Timing Belt and Tensioner Kit
2006 Ridgeline w/3.5L Eng.:
Belt & Tensioner Kit w/Water Pump......................t TBK329WP
2002-1998 Passport w/3.2L Eng.:
Belt & Tensioner Kit w/Water Pump......................t TBK303WP
1997-1994 Passport w/3.2L Eng.:
Belt & Tensioner Kit w/Water Pump......................t TBK221WP
Engine (Cont.)
Timing Belt and Tensioner Kit (Cont.)
1996-1994 Passport w/2.6L Eng.:
Belt & Tensioner Kit w/Seals..................................... t TBK147P
3
1
1
4
2 3
4
2
t Interference engine for most applications.
6. 2
Table of contents
Applications
Manufacturers model index........................................................................................... 22
Passenger car and light truck........................................................................................ 24
Information
Engine drive systems.........................................................................................................3
Failure analysis overview................................................................................................ 11
Chrysler application installation information............................................................... 17
Cadillac, Saab and Saturn application installation information................................ 19
Ford & Mercury application installation information.................................................. 20
Abbreviation list............................................................................................................... 21
Kit contents....................................................................................................................... 51
Frequently asked questions............................................................................................ 74
Reference
Belt performance and quality........................................................................................ 75
Belt specifications............................................................................................................ 76
Timing belt removal and installation............................................................................ 81
Typical timing belt installation........................................................................................ 82
Troubleshooting and failure analysis for timing belts................................................. 83
Belt life vs correct tension.............................................................................................. 84
Analyzing belt wear and damage.................................................................................. 85
Troubleshooting and failure analysis for all other components................................ 86
Good practices and helpful hints................................................................................... 89
Setting up automatic tensioners: a typical example................................................... 90
Kit reference buyer's guide............................................................................................. 92
7. 3
Engine drive systems
Technology and material changes
Many components and systems in the engine depend
on the correct functioning of the timing and auxiliary
drives. This is also driving the technology and design
of these systems, so they can live up to the more
demanding criteria required.
Timing drive system
The controlled operation of this system is dependant
on either a chain or a belt. A general drive for design
improvement for performance gain, coupled with the
pressure to reduce emissions, have seen twin overhead
cam, multi-valve engines become commonplace.
Timing belt
A timing belt is typically rubber with high-tensile fibers
(e.g. fiberglass or Kevlar) running the length of the
belt. Rubber degrades with higher temperatures and
contact with motor oil and antifreeze. Therefore, the life
expectancy of a timing belt is lowered in hot or leaky
engines. While older belts were of chlorobutadiene
rubber material and trapezoidal shape, today’s modern
belts are even more specific to particular engine
designs, with subtle profile changes to the curvature
of the teeth. In addition the improved material means
these new designs optimize the power transfer without
wear or noise, reaching ever higher lifespans in excess of
over 93,000 mi/150 000 km.
Timing chains
Encased on the front of the engine, this power
transmission drive frees up space to give the auxiliary
system more space. On average, these chain systems
have a longer life span on recent engines. The typical
life of a chain is around 74,500 – 155,300 mi/120 000
km – 250 000 km. The disadvantage with chains is that
they are noisy in comparison with belts and they lack
the capacity to handle modern hp injection systems.
In the immediate future (5–10 years), new cars sold
with chains fitted on the engine drive system will rise by
around 50%.
Timing system, belts vs. chains
For car manufacturers, engine assembly is all about
numbers built – faster. Unfortunately, the time taken
for the ABTU and belt on the timing system to be set up
correctly, can eat into production time. Chains are easier
and faster to install. This fact contributes to the use of
chains today. The use of high performance material such
as HSN, advanced automatic tensioner units, specialized
bearings and pre-set tensioner springs for speedier and
easier mounting, adds up to belt systems that reach
the life time level of chains, while still offering design
flexibility, cost and weight savings, as well as easier
maintenance in the aftermarket. This is an advantage
when it comes to car manufacturers’ choice. But, for
now, chains are still the preferred option.
Timing belt system
Timing chain system
8. 4
Engine drive systems
Manual timing belt tensioner (MTBT)
The original timing assembly process, when mounting
onto the engine, was accomplished by manually
setting the tensioner by rotating the tensioner unit and
locking it permanently at the required tension. This
meant that as the engine warmed up to ever higher
temperatures, and new designs required different
operating characteristics with higher performance, the
fixed tension control from the manual BTU was not
able to reach the desired performances for extended
component life required by the designers.
Automatic timing belt tensioner (ATBT)
The ATBT promotes longer belt life, by better handling
of the engine loads, and is less affected by running
temperature variations after correct set up. This is why
it has become the norm fitted to today’s belt-driven
engines. These tensioner units are made up of many
functional sub-components that ensure the correct
operation of the automatic tensioner.
Key ATBT components:
1. Mounting eccentric: Provides smooth adjustment by
rotation to facilitate correct set-up of initial tension.
2. Bushing: Self-lubricating, highly wear-resistant
polyamide component. Primary source of damping.
Also provides axial alignment and sliding surface.
3. Bearing: Maintenance-free and sealed for life. The
component is specifically adapted for the relevant
application.
4. Pulley: Metal or polyamide, depending on the
application.
5. Hub: Transmits the torque of the spring to the pulley.
6. Spring: Designed to provide optimum belt tension
control for engine running.
7. Pivot shaft/plate: Ensures proper placement and
angular location on engine block.
1.
2.
3.
4.
5.
6.
7.
MTBT ATBT
MTBT
ATBT
Belt losing grip
Noise generation
Belt load, N
Engine temperature, °F / °C
250
200
150
100
50
0
32 / 68 / 104 / 140 / 176 / 212 / 248 / 284 / 320 /
0 20 40 60 80 100 120 140 160
MTBT vs ATBT chart
9. 5
Engine drive systems
Variations of ATBT design
Even an apparently basic pulley component may need
to be used differently when the engineer sets his
specification. There are pros and cons when it comes
to the optimum choice of materials best suited to a
particular engine’s requirements:
The polyamide pulley:
Positives:
• Polyamide is light.
• Polyamide retains heat longer than metal.
• The clearance of the bearing is not affected by the
moulding.
Negatives:
• Dirt and grit can be embedded in the plastic, risking
belt damage.
• Moulding process can affect the bearing and grease
life.
The metal pulley:
Positives:
• Thermal properties of steel dissipate heat efficiently.
• Metal resists abrasion to maintain proper belt
alignment.
• Metal deflects dirt and grit particles.
Negatives:
• The assembly can affect the clearance of the bearing
causing operation and life issues.
• Metal is heavy compared to plastic.
Hydraulic automatic timing belt tensioner
The hydraulic system design is mainly used on
applications with high loads and/or angular vibrations,
where a mechanical automatic tensioner cannot provide
sufficient damping or tensioner movement. Due to weight
and space limitations, the design is limited to a few
engine types and is not expected to become as common
as the more compact ATBT.
The unit can operate with a large range of dynamic belt
lengths, unlike the mechanical tensioner, due to the
length of stroke of the actuator and the lever design. The
damping characteristics from the piston are particularly
suitable for large V6/V8 engines (amongst others).
Hydraulic automatic timing belt tensioner
These units are made up of many functional sub-components that
provide the correct operation of the automatic tensioner.
10. 6
Engine drive systems
Aggressive oils
The additives used with engine oils have changed in
order to cope with increasing temperatures and the
extension of oil change intervals. This has led to oils
attacking some conventional fluorpolyamide (rubber)
materials. PTFE is inert, so the changes to material
properties, and hence reduced sealing capability, have
been eliminated.
Robust design
The design of a PTFE seal means that the sealing lip
contacts the shaft over a width of 0.079-0.118 in/2–3
mm. This compares with a width of 0.004-0.008 in/
.1–.2 mm for a conventional rubber seal. If there is
a small defect in the shaft’s sealing lip, then with a
conventional seal, this would probably lead to leakage.
With the much wider sealing track of the PTFE, the
probability that the same defect will lead to leakage is
much reduced.
Reduced wear
Shaft wear is an important issue. With PTFE, because of
the wide contact area, the depth of wear grooves in the
shaft is significantly reduced.
Shaft contact with rubber seal.
Shaft wear conventional rubber materials.
Shaft wear with PTFE.
Valve stem seal
Oil pan drain plug Valve cover seal Rear retainer assembly / Rotostat
Static plug Spark plug tube seal Sensor seal
Shaft contact with PTFE seal.
shaft
shaft
line contact surface contact
11. 7
Engine drive systems
Cooling system
With gasoline most of the energy (about 70%) is
converted into heat from the effects of friction and
combustion. The cooling system must keep the engine
from overheating, obviously, but it should also be
efficient, allowing the engine to operate within a tight
temperature range to reduce friction.
Water pump
Water pump requirements, like other components, are
becoming more exact and demanding; pump rates,
pressures and fluid flow paths contribute to the efficient
operating temp of the engine, and provide precise
cooling performance.
Water pumps have been constantly improved through
the years, but due to the aggressive operating
environment of the engine, a water pump replacement
will most likely be performed sometime during the life
of a motor vehicle. Today, they are very often an integral
part of the timing drive system.
Timing belt kit, including water pump. Here is a popular VAG engine timing layout where, typically the
water pump is an integral part.
12. 8
Engine drive systems
Auxiliary drive system
The role of this particular drive system is growing
in importance every day, as modern cars cover
more demanding consumer requirements; comfort,
electronic devices, fuel efficiency, etc. PAS (power
assisted steering) and AC (air conditioning), once costly
options are now standard on a wide range of cars. The
aftermarket for multi-V belt idler and tensioner units
has seen a steady rise as a result of this technology
being implemented. The auxiliary drive system will
continue to grow in importance for the modern car in
the coming years.
Multi-V belt
The multi-V drive belt has become standard on new
applications since the late 90’s. The design covers the
need to drive multiple accessories from one belt around
a compact area. The belt therefore needs to be flexible
to offer tight wraps and return the belt on small radius
pulleys, but also to be able to handle the higher tension
needed to “grip” the functioning components without
slippage. Reliability and endurance should similarly
match the timing system on the engine.
The multi-V belt operates in tough environments,
sometimes low down on the car and often exposed
to dirt, water and oil, and with more utilities added
to the car, the strain on the belt increases. Other
arrangements may see the system operate high up in a
compact area where higher temperatures will affect the
belt. Newer materials, such as EPDM, are common on
the belts offering superior performance features.
Even though the multi-V belt profile (pk) has become
a recognized standard, there is no standard belt for
the application. For every engine model there can be
more than a handful of different auxiliary drive belt
arrangements (different span lengths), depending
on the type of equipment fitted. This span
length is very important, down to the
last millimeter for optimum operation.
A typical timing or multi-V belt will, in its lifetime, travel a distance
equal to one lap around the world, where the teeth of the timing
belt takes as many “bites” as there are people in the world. When
the lap is completed, and sometimes sooner, as people today travel
longer distances more quickly, the belt and bearing components
need to be replaced.
13. 9
Engine drive systems
Accessory belt idler pulley (ABIP)
Idler
Idlers can be found in varied positions on the engine
timing system, each with specific loading and
performance conditions. Today’s engineers are trying to
find ways to increase the life span of the idler to reach a
target of 124,300 mi/>200 000 km (with the eventual
aim of it having the same life span as the engine). They
need to withstand the higher operating conditions
through component design evolution. For example, a
significant area of improvement is bearing sealing and
greases. Finally more polyamide pulleys fitted results in
overall weight gain for the designers.
Engine seal
Engine sealing arrangements have advanced
dramatically over the last few years. Although hidden
from view, modern sealing techniques, such as
moulded-in-place permanent gasket solutions, have
delivered significant improvements in achieving oil-tight
assemblies for the effective life of an engine. Dynamic
sealing, for crankshafts and camshafts, is now receiving
similar design and material attention.
Traditional elastomeric lip seals are today being replaced
by PTFE (PolyTetraFluoroEthylene) thin film seals. They
offer extended sealing life and a far greater level of
protection from chemical attacks. This is a particular
problem with diesel engines and some of the more
exotic synthetic based oils. However, these provide the
extended service intervals demanded in the market-place.
The idler pulley allows the belt to be correctly wound
(providing optimum wrap angle) around the driven
components, while also reducing the free belt length,
which, if not accurately calculated into the design build,
could cause excess vibrations and noise.
Polyamide idler, with
single row bearing (Fiat).
Traditional engine shaft seal design
Modern engine shaft seal designs - PTFE:
1. Sealing lip (varied material)
2. Metal or rubber casing
3. Contact spring
Standard PTFE-seal with
elastomeric or felt dust lip.
4th Generation PTFE-seal
with improved durability
and “easy-assembly”.
Unitized PTFE-seal for
heavy contamination.
Idler
slack span
tight span
engine
rotation
Metal idler, with
double row bearings (VW).
1.
2.
3.
14. 10
Engine drive systems
Automatic accessory belt tensioner unit
(AABT)
In the auxiliary drive, the control tension can be
provided by an hydraulic piston damping solution. This
is a mechanical belt tensioning device based on spring
and damping components to provide the running
tension required for the belt. Due to the materials
used, high and consistent damping values, irrespective
of temperature and frequency, as well as minimal
running-in effects, can be achieved.
It is usually very easy to set up this unit for assembly
for engine build for manufacturers and also for
maintenance. It is normally bolted on and pin-released.
The tension is, of course, optimized based on specific
belt and components fitted into the system.
Future trends
One direction being pursued to lower fuel consumption
is the new technology called “stop/start” based on a
combined starter/alternator and electronics.
When the car is moving around town, for example,
below 30 mi/hr/50 km/hr, or if it stops a traffic jam, the
engine is automatically shut down and electric motors
powered from battery could drive the vehicle. When
speed increases to a suitable level or the car needs to
accelerate, the normal combustion engine is restarted
automatically via the auxiliary drive system. So, in effect,
this system is restarted via the combined alternator/
starter.
Power steering may move away from auxiliary drive
systems in the future, due to an electrical conversion
of the function.
AABT
15. Failure analysis overview
11
90% of engine running faults are caused by basic
problems, many of which can be prevented by correct
mounting and maintenance.
This chapter will cover some of the most common
drive system failures and how to prevent them from
happening.
Engine
Today, the timing cycle of the engine is more crucial
than ever. Almost every new engine is the “interference”
type, with the valves and pistons in close proximity. A
broken or “tooth-jumped” timing belt can cause the
piston to crash into an open valve, resulting in bent
valves, broken pistons, and serious engine damage.
Even though the older “non-interference” engines with
timing belt problems may not sustain the same type of
damage as “interference” engines, the driver will still be
stranded with a dead engine beside the road.
Timing drive system
Engine oil seal
Common failures:
1. Heat builds up (poor lubrication).
2. Stress due to out of round shaft (worn crankshaft/
camshaft).
These conditions will eventually cause the seal to fail,
with leakage and/or ingress of particles into the oil as
a result.
- Don’t let this happen to your customers!
An example of engine
damage caused by timing
component failure or
tooth jump.
Here you can see oil on
the tensioner. A leaking
oil pump or damaged
engine seals will cause
the tensioner to fail.
1. Heat builds up 2. Stress due to out of round shaft
16. Failure analysis overview
12
Timing belt
The material in the belt is sensitive to bending
(crimping) more than its maximum natural curve, and
should therefore be treated gently.
Common failure causes:
1. Incorrect tension.
2. Misalignment.
3. Foreign object in the drive system (oil, cooling liquid,
water, stone, etc).
4. Contamination or uneven surface between the
tensioner mounting plate and the engine block.
5. Tensioner/Idler failure.
6. Worn crankshaft or camshaft dampers.
Engine type
Depending on the design of the engine, the piston
and valve paths may “interfere” with one another, and
incorrect timing in their movements may result in
the piston and valves colliding. (Such designs are also
called “interference head” or “interference engines”.
Conversely, non-interfering engines are called “free-
wheeling” or “non-interference” engines.)
You can see on the tensioner that the surface has been colored blue/
brown from the heat. On the belt you see traces of wear in the middle.
This indicates that the tension is too high, i.e. bad mounting.
1. Incorrect tension
2. Misalignment (incorrect centering of the belt)
The edge of the belt has been worn down to almost half its size. On
the tensioner, you can see clear marks indicating a misaligned belt.
You can see on the belt pictures, showing both sides, that a foreign
object, or perhaps a damaged tooth on the pulley, have made marks in
the belt that eventually cracked.
If the belt has been contaminated with oil or water, you will see this by
the glazing on the belt. You may feel it, as the belt will be soft and the
rubber coming away from the construction.
4. Contamination on the belt
3. Foreign object in the timing drive system
17. Failure analysis overview
13
Tensioner and idlers
A common reason for bearings to fail early, is
the tension being too high or when there is load
misalignment outside the set parameter for that bearing
design. Wrong belt centering will cause the bearing to
run off line due to an increased radial load. See picture
to the right.
Load forces are only one of the key factors that need to
be calculated in the design phase of the tensioner.
The International Standards Organisation (ISO) has
adopted the SKF Life Theory in ISO 281 to calculate
bearing life.
Always use the correct equipment to set the belt tension
when a TBT is changed. Check car manufacturers’
specifications for correct tension value.
Common failure causes:
1. Bad mounting. The component has been damaged
when mounting or adjusting the tension.
2. Wrong torque. The mounting bolts have not been
tightened to the car manufacturers’ specification.
3. Leaking oils/fuels will cause plastic damage
(softening/cracking).
4. The engine is not at the ambient temperature when
the components are mounted and set up.
5. Mounting of tensioners/idlers onto uneven or
contaminated surfaces on the engine block.
6. The timing cover may be damaged and foreign
objects can enter the timing system.
7. If the idler or tensioner is dropped, even if the
external damage does not seem important, internal
components (balls, cage, etc.) can be weakened or
damaged.
Radial load, Fr
Axial load, Fa
Combined load
The tensioner has been blocked, stopping correct rotation, caused
by damage to the tensioner during tension set-up and initiated from
incorrect mounting onto the engine block.
The indicator arm has been hammering on its end stop.
The mark from the mounting bolt around the mounting hole is clearly
visable. It has weakend the bolt and loosened the tensioner.
You can see friction marks
and corrosion on the back of
the tensioner. This is caused
by the tensioner running
loose and has turned during
the engine running.
1. Bad mounting
2. Wrong torque
5. Mounting problem
18. Failure analysis overview
14
Troubleshooting the ATBT set-up:
1. The mounting bolt is not correctly torqued (to
car manufacturer recommendations). If it is not
tightened, the tensioner will gradually loosen under
running, and the indicator arm may come into
contact with the end stop. The engine begins to run
rough as the timing is affected, before failing.
2. Incorrect mounting (location pegs or holes are not
correctly located).
3. Correct set-up is not possible for proper running
of the engine. Check for correct back plate locating
point; some engines can indicate incorrect
alternatives causing visual error.
4. Unevenness between the mounted tensioner plate
and the engine block can cause incorrect tension/
belt run out or even block bearing rotation. Check for
debris or possible fouling points on mounting.
5. The indicator arm is not set to the correct tension
position. You need to turn the engine twice to
reconfirm a correct position. If it is not in the advised
position, remount and perform the set up process
again. Don’t take the risk, play it safe and be sure.
Hydraulic tensioner
Apart from the traditional weaknesses on the tensioner
pulley component, the actuator part can be affected by
wear and premature failure.
Common failure causes:
1. An oil leakage through the seal. Even the smallest
leak in the actuator through time will cause gradual
loss of damping effect and possible belt damage
(ripped teeth from poor tension may be found).
2. Failure in the spring or valves will lead to system
failure, and probably engine damage, very quickly.
To maintain correct function, this damping control unit
should be changed at the same period as the timing belt
and pulleys (around 70,000 mi/around 110 000 km).
The indicator arm on the ATBT is broken.
1. Wrong torque
1. Oil leak through the seal of the hydraulic tensioner
19. Failure analysis overview
15
Water pumps
Although modern coolant pumps are maintenance-free
for a number of years, they are not fault-free and some
problems do occur:
A water pump leak can be due to:
1. Damaged water pump seal due to incorrect
mounting.
2. The use of excessive or wrong sealant type with
gaskets or O-rings. This can lead to early leakage or
even incorrect mounting angle when tightened. This
leads to incorrect centering of the belt. Here, you
can see rubber residue on the idler and the coating
around/under the O-ring.
3. A badly corroded water pump, whose lifespan has
expired. This pump was not changed in time during
the timing system maintenance. A severe leakage of
coolant past the mechanical seal and out of the drain
vent, washed the grease from the bearing spindle
and this lead to the failure/breakdown.
4. Abrasive particles originating from metal corrosion/
erosion are carried around by the circulating coolant
and score the seal contact faces.
5. Worn spindle bearings allow shaft misalignment to
occur between the seal contact faces.
The water pump may be inefficient due to:
1. Metal corrosion/erosion gradually destroying the
form of the impeller vanes.
2. Excessive end float of the impeller spindle in its
bearing increasing the working clearance between
the impeller vanes and the pumping chamber.
3. Internal engine condition and component life is
highly dependant on good coolant, which prevents
the build-up of corrosive and/or calcareous
materials that are harmful to a water pumps’
components. A thorough flush through and complete
refill with approved coolant type for the engine is
recommended to ensure maximum life from a new
water pump.
1. Incorrect mounting
2. Excessive sealant
3. Life-span expired
20. Failure analysis overview
16
If you hear noise coming from the water
pump, it could be for one of the following
reasons:
1. Wear in the impeller spindle shaft bearing assembly
due to foreign particles through grease loss.
2. Airlocks, due to an improperly purged cooling system.
3. Bad coolant forms coating on mechanical seal giving
rise to noise.
Auxiliary drive system
Multi-V belt
Common causes of failure:
1. Damage to the timing system, causing an engine
breakdown.
2. Overheating, if it is water pump driven.
3. Loss of power steering.
4. Dead battery, i.e. non-operational alternator.
5. In the long term the stop/start mechanism will not
function, thus the car will not function if the belt
breaks when the car is in the stop mode.
Damage from other components can also be the cause
of the system failure – mounting brackets, damper
units, and injection/water pumps.
Tensioner and idler
Common failures often follow similar patterns to the
timing system tensioners and idlers. However, the metal
parts are more prone to corrosion and material debris
due to their low position on the engine in relation to
the road. Any damaged covers will allow this material to
enter.
3. Wrong/bad coolant
1. Damage to the timing system
The driver of a car with a broken multi-V belt could be left with a
non-functioning alternator, loss of power steering or, in the worst
case, even a belt that has entered the timing system resulting in
engine breakdown.
Loss of power steering.
Tensioner bracket and shaft has become
misaligned due to heavy belt load.
Note: For more detailed information on troubleshooting and failure analysis see pages 86 thru 88.
21. 17
SKF Timing kits
Application installation information—Chrysler
TBK245WP, TBK245AWP & TBK245BWP
Chrysler 2.0L SOHC—Timing drive tensioner troubleshooting
The 2.0L Chrysler engine has gone through several timing belt tensioner design changes
since its introduction in 1996 through 2005. Three different timing belt tensioners
were used between 1995 and 2005, and tensioner TBT55016 is considered the
recommended replacement assembly for all three. Not included in any TBK kit, the
TBT55016 is only available separately to ensure proper replacement.
First design
The 2.0L engine was originally produced with the hydraulic timing belt tensioner
assembly TBT55008. The complete assembly is not sold in kits. The complete assembly
TBT55008 is available separately if needed.
The pulley used with this design can be serviced with pulley part number TBT51001, the
pulley bearing is included in TBK245WP.
TBT51003 has the TBT51001 bearing, with hydraulic tensioner bracket attached.
TBT51003 is included with kit TBK245BWP.
TBK245WP, TBK245AWP or TBK245BWP all include a W1201300 water pump.
Note: Previous timing belt replacement(s) may have utilized the TBT55016 design. Check
components on vehicle to make sure the correct kit is selected.
Second design
The second timing belt tensioner design is no longer available. The recommended
replacement is tensioner TBT51006 which is available in kit TBK245AWP or to retrofit
the complete assembly. TBT55016 is available separately if needed.
Third design
Tensioner TBT55016 is a direct replacement for this design. The tensioner without
the bracket is available as part number TBT51006. This tensioner (without bracket) is
included in TBK245AWP which also includes a W1201300 water pump. TBT55016 is
available separately if needed.
TBT51001
TBT51003
Second design w/steel bracket
TBT51006 Third design—TBT55016 w/aluminum
bracket
First design—TBT55008 assembly
w/TBT51003 mounted
22. 18
SKF Timing kits
Application installation information—Chrysler
TBK265WP, TBK265AWP & TBK265BWP
Chrysler 2.4L DOHC—Timing drive
TBK265AWP - Idler (TBP51007) and Tensioner (TBT51016)
Fits Chrysler 2003 and newer vehicles, but can be retrofitted on older vehicles with some modification of the inner timing cover.
TBT51016 is a complete assembly with TBT51006 mounted on bracket.
TBK265WP - Idler (TBP51007) and Tensioner (TBT51006)
Fits Chrysler 2003 and newer vehicles. 2002 and older vehicles will require modification of the inner cover if the complete assembly
TBT51016 is to be installed.
TBK265BWP - Idler (TBP51007) and Tensioner (TBT51004)
Replaces original equipment on 2002 and older vehicles.
Note: Previous timing belt replacement(s) on 2002 and older vehicles may have utilized the TBT51016 design.
Check components on vehicle to make sure the correct kit is selected.
TBP51007
TBP51007
TBP51007
2003 and newer inner
timing cover
2002 and older inner
timing cover
TBT51016 assembly
w/ TBT51006 mounted
TBT51006
TBT51004
23. SKF Timing kits
Application installation information—Cadillac, Saab, Saturn
19
TBK285P, TBK285AP & TBK285BP
Cadillac, Saab, Saturn V-B 3.0L
All three makes with V-6 3.0L utilize the same lower idler (TBT25500).
Note: Verification of the tensioner/idler bracket on the vehicle is recommended prior to selecting a TBK as designs changed in mid-model years
1999 and 2002.
Original design utilized a fixed lower idler which is no longer available. TBT25500 is available and is an adjustable idler. Note:
TBT25500 must be adjusted properly to prevent the belt from “tracking off the drive”. Validate the spacer thickness before
reinstalling TBT25500 to ensure proper distance from engine block is maintained. If spacer is damaged, do not substitute, obtain
correct spacer from OEM manufacturer. Spacer is not provided in kit to ensure you re-use old, undamaged spacer or replace spacer
with correct thickness from the OEM manufacturer.
TBK285P—Includes seal and TBT15500 assembly. This assembly is set
at the factory. Avoid loosening the adjusters prior to reading full set of
instructions included in kit to prevent belt mis-alignment. Adjust belt with
TBT25500.
1999 (Early)..........................................Cadillac Catera 3.0L
1998-97................................................Cadillac Catera 3.0L
1997-95................................................Saab 9000 3.0L
1999 (Early)..........................................Saab 9-5 3.0L
TBK285AP—Includes seals and TBT55002 assembly. This assembly is
set at the factory. Avoid loosening the adjusters prior to reading full set of
instructions included in kit to prevent belt mis-alignment. Adjust belt with
TBT25500.
2001-00...............................................Cadillac Catera 3.0L
1999 (Late)...........................................Cadillac Catera 3.0L
2002 (578511 & before)....................Saturn L-Series 3.0L
2001-00...............................................Saturn L-Series 3.0L
TBK285BP—Includes seals and TBT55001 assembly. This assembly is
set at the factory, avoid loosening the adjusters prior to reading full set of
instructions included in kit to prevent belt mis-alignment. Adjust belt with
TBT25500.
2003-00................................................Saab 9-5 3.0L
1999 (Late)............................................Saab 9-5 3.0L
2005-03................................................Saturn L-Series 3.0L
2002 (578512 and after)....................Saturn L-Series 3.0L
2003-02................................................Saturn Vue 3.0L
TBT25500 Front TBT25500 Back
24. SKF Timing kits
Application installation information—Ford & Mercury
20
TBK294WP, TBK294AWP & TBK294BWP
Ford & Mercury 2.0L engines
All of these kits fit 2.0L Ford engines. Note: the timing belt drives on these engines are very sensitive to belt tension. If the
tensioner is not adjusted correctly the belt will lose tension and walk off the drive. This may damage the belt and possibly
damage other engine components.
Special installation instructions for TBK294WP, TBK294AWP & TBK294BWP
• Proper installation and belt tension is critical to insure the belt does not track off the drive.
• Ford Contours, Mercury Cougars and Mystiques built after 3/28/99 must use TBK294AWP.
Ford Contours, Mercury Cougars and Mystiques built before 3/28/99 use TBK294WP. Confirm idler pulley diameter is
correct before opening kit. (Not required for TBK294BWP)
• Ford Escorts built after 2/9/99 must use TBK294AWP, and those built prior to 2/9/99 should use TBK294WP. Confirm idler
pulley diameter is correct before opening kit. (Not required for TBK294BWP)
• Tensioner mounting bolt must be installed with proper torque.
• Base plate tab on automatic tensioner must be inserted in hook up slot.
• Tensioner adjustments should be made in a counterclockwise direction only.
After installation is complete, with the top timing belt cover removed, start the vehicle, and from a safe distance observe the
timing belt. Belt should be tracking straight and consistent over the camshaft sprockets. Shut off vehicle and check tensioner
for proper adjustment. Installation instructions for tensioning must be followed completely. Camshafts must be secured
with cam sprockets free to rotate on shafts prior to adjusting the tensioner. Repeat this procedure until proper tensioner
adjustment is achieved. Improper tension will cause the belt to track off the pulley. Do not attempt to adjust tension while
the engine is running.
TBK294WP
The upper idler (TBP64004) in
TBK294WP has an outside diameter of
70 mm / 2.756 in. (w/DOHC)
TBK294AWP
The upper idler (TBP64005) in
TBK294AWP has an outside diameter
of 60 mm / 2.362 in. (w/DOHC)
TBK294BWP
TBK294BWP uses the same upper idler
as TBK294AWP and does NOT have a
lower idler pulley. (w/DOHC)