Everything you wanted to know about Timing Belts...

But were too embarrassed to ask!

Interesting. I have often asked Toyota Service managers and tech when to
replace the Timing belt on verious cars: "The belts been on the car for 5
years!" Ans: "Replace it at XX,XXX miles!" I always wondered why Mileage
and not elapsed time. Well: (take a look at the LAST line...)




For preventative maintenance, and to comply with the recommended replacement
interval specified by the vehicle manufacturer. Rubber timing belts
contain reinforcing cords of fiberglass or Kevlar. These cords keep the
belt from stretching or breaking, which is no simple task considering the
strain that is on the belt. Many other engines use a steel chain for this
same purpose.

As the belt accumulates miles, the constant bending every time it passes
around a pulley plus constant exposure to heat causes the rubber to harden
and become brittle. Little cracks start to appear in the rubber. These
cracks are not serious as long as they’re not too deep or cause chunks
of rubber to break loose. The constant stress, heat and bending also
weakens the fibers that make up the reinforcing cords. Eventually the
point is reached where something gives and the belt fails.

Until recently, the incidence of failure peaked sharply after about 60,000 miles,
so the vehicle manufacturers mostly recommended replacing the best at
60,000 mile intervals. On newer engines, this interval has been extended
to as much as 100,000 miles thanks to improved belt materials.

So what happens if you don’t replace the belt? Maybe nothing. Some belts just
keep going and going and will last the life of the engine. Others may fail
at 60,001 miles or even sooner. Since no one can predict the exact mileage
at which a timing belt will fail, the safest bet is to follow the vehicle
manufacturer’s recommendations.

WARNING: A timing belt failure can cause extensive engine damage on many
overhead cam engines. If the engine lacks sufficient valve-to-piston
clearance, a belt failure can allow the valves to hit the pistons
destroying both. The cost of replacing the belt at the recommended
interval, therefore, is cheap insurance compared to the cost of replacing
or rebuilding the engine.

Engines with timing belts that are at risk for this type of damage include:
# All Accura four cylinder, five cylinder and V6 engines
# Audi 1.6L and 2.0L diesel engines
# Buick Skyhawk 1.8L and 2.0L engines
# Chevrolet Geo Metro 1.0L three cylinder engines
# Chevrolet Geo Spectrum and Prizm 1.5L and 1.6L engines
# Chevy Luv pickup truck 2.2L diesel engines
# Dodge and Plymouth Colt 1.5L and 1.6L engines
# Eagle Summit and Vista 1.5L and 1.6L engines
# Eagle Talon 2.0L engines
# 1981-85 Ford Escort (and Mercury Lynx) 1.6L engines
# 1985 Ford Tempo and Ranger pickup 2.0L diesel engines
# Ford Probe 2.0L engines
# All Honda four cylinder engines
# All Hyundai four cylinder engines
# Infinity 3.0L V6 engines
# All Isuzu four cylinder engines
# Mazda 2.2L four cylinder and 3.0L V6 engines
# Mitsubishi 1.5L, 1.6L and 2.0L engines
# All Nissan engines
# All Porsche engines
# Suzuki 1.3L engines
# Toyota Tercel 1.5L engines
# Toyota pickup 2.2L and 2.4L diesel engines
# Volkswagen 1.5L and 1.6L diesel engines
# All Volvo four cylinder engines
# All Yugo engines (if any are still running).

The later 3.5 Nissan has timing chains, my 96 Maxima had them. It is a
great engine.
Ron[color=blue]
>
>[color=green]
> > As the belt accumulates miles, the constant bending every time it passes[/color]
> around a pulley plus constant exposure to heat causes the rubber to harden
> and become brittle. Little cracks start to appear in the rubber. These
> cracks are not serious as long as they're not too deep or cause chunks
> of rubber to break loose. The constant stress, heat and bending also
> weakens the fibers that make up the reinforcing cords. Eventually the
> point is reached where something gives and the belt fails.
>
> Until recently, the incidence of failure peaked sharply after about 60,000 miles,
> so the vehicle manufacturers mostly recommended replacing the best at
> 60,000 mile intervals. On newer engines, this interval has been extended
> to as much as 100,000 miles thanks to improved belt materials.
>
> So what happens if you don't replace the belt? Maybe nothing. Some belts just
> keep going and going and will last the life of the engine. Others may fail
> at 60,001 miles or even sooner. Since no one can predict the exact mileage
> at which a timing belt will fail, the safest bet is to follow the vehicle
> manufacturer's recommendations.
>[color=green]
> > Engines with timing belts that are at risk for this type of damage include:[/color]
> # All Accura four cylinder, five cylinder and V6 engines
> # Audi 1.6L and 2.0L diesel engines
> # Buick Skyhawk 1.8L and 2.0L engines
> # Chevrolet Geo Metro 1.0L three cylinder engines
> # Chevrolet Geo Spectrum and Prizm 1.5L and 1.6L engines
> # Chevy Luv pickup truck 2.2L diesel engines
> # Dodge and Plymouth Colt 1.5L and 1.6L engines
> # Eagle Summit and Vista 1.5L and 1.6L engines
> # Eagle Talon 2.0L engines
> # 1981-85 Ford Escort (and Mercury Lynx) 1.6L engines
> # 1985 Ford Tempo and Ranger pickup 2.0L diesel engines
> # Ford Probe 2.0L engines
> # All Honda four cylinder engines
> # All Hyundai four cylinder engines
> # Infinity 3.0L V6 engines
> # All Isuzu four cylinder engines
> # Mazda 2.2L four cylinder and 3.0L V6 engines
> # Mitsubishi 1.5L, 1.6L and 2.0L engines
> # All Nissan engines
> # All Porsche engines
> # Suzuki 1.3L engines
> # Toyota Tercel 1.5L engines
> # Toyota pickup 2.2L and 2.4L diesel engines
> # Volkswagen 1.5L and 1.6L diesel engines
> # All Volvo four cylinder engines
> # All Yugo engines (if any are still running).[/color]

"ronbon" <n877@msn.com> wrote in message
news:1165377839.737421.91980@80g2000cwy.googlegroups.com...[color=blue]
> The later 3.5 Nissan has timing chains, my 96 Maxima had them. It is a
> great engine.
> Ron[color=green]
>>[/color][/color]

The first line of the guide says "Engines with timing belts..."

IOW, engines with chains are not included in the list.
--

Ray O
(correct punctuation to reply)

As the belt accumulates miles, the constant bending every time it passes[color=blue][color=green]
>> around a pulley plus constant exposure to heat causes the rubber to
>> harden
>> and become brittle. Little cracks start to appear in the rubber. These
>> cracks are not serious as long as they're not too deep or cause chunks
>> of rubber to break loose. The constant stress, heat and bending also
>> weakens the fibers that make up the reinforcing cords. Eventually the
>> point is reached where something gives and the belt fails.
>>
>> Until recently, the incidence of failure peaked sharply after about
>> 60,000 miles,
>> so the vehicle manufacturers mostly recommended replacing the best at
>> 60,000 mile intervals. On newer engines, this interval has been extended
>> to as much as 100,000 miles thanks to improved belt materials.
>>
>> So what happens if you don't replace the belt? Maybe nothing. Some belts
>> just
>> keep going and going and will last the life of the engine. Others may
>> fail
>> at 60,001 miles or even sooner. Since no one can predict the exact
>> mileage
>> at which a timing belt will fail, the safest bet is to follow the vehicle
>> manufacturer's recommendations.
>>[color=darkred]
>> > Engines with timing belts that are at risk for this type of damage
>> > include:[/color]
>> # All Accura four cylinder, five cylinder and V6 engines
>> # Audi 1.6L and 2.0L diesel engines
>> # Buick Skyhawk 1.8L and 2.0L engines
>> # Chevrolet Geo Metro 1.0L three cylinder engines
>> # Chevrolet Geo Spectrum and Prizm 1.5L and 1.6L engines
>> # Chevy Luv pickup truck 2.2L diesel engines
>> # Dodge and Plymouth Colt 1.5L and 1.6L engines
>> # Eagle Summit and Vista 1.5L and 1.6L engines
>> # Eagle Talon 2.0L engines
>> # 1981-85 Ford Escort (and Mercury Lynx) 1.6L engines
>> # 1985 Ford Tempo and Ranger pickup 2.0L diesel engines
>> # Ford Probe 2.0L engines
>> # All Honda four cylinder engines
>> # All Hyundai four cylinder engines
>> # Infinity 3.0L V6 engines
>> # All Isuzu four cylinder engines
>> # Mazda 2.2L four cylinder and 3.0L V6 engines
>> # Mitsubishi 1.5L, 1.6L and 2.0L engines
>> # All Nissan engines
>> # All Porsche engines
>> # Suzuki 1.3L engines
>> # Toyota Tercel 1.5L engines
>> # Toyota pickup 2.2L and 2.4L diesel engines
>> # Volkswagen 1.5L and 1.6L diesel engines
>> # All Volvo four cylinder engines
>> # All Yugo engines (if any are still running).[/color]
>[/color]

"Hachiroku ????" <Trueno@AE86.gts> wrote in message
news:n0rdh.1025$4p2.783@trndny07...[color=blue]
>
> But were too embarrassed to ask!
>
> Interesting. I have often asked Toyota Service managers and tech when to
> replace the Timing belt on verious cars: "The belts been on the car for 5
> years!" Ans: "Replace it at XX,XXX miles!" I always wondered why Mileage
> and not elapsed time. Well: (take a look at the LAST line...)
>[/color]

I believe that Toyota recommends at XX,XXX miles or YY months, whichever
comes first.

--

Ray O
(correct punctuation to reply)

"Hachiroku ????" <Trueno@AE86.gts> wrote in message
news:n0rdh.1025$4p2.783@trndny07...[color=blue]
>
> But were too embarrassed to ask!
> # All Porsche engines[/color]

all Porsche engines are interference type?

That would be a VERY expensive belt to have break on you! Glad I can't
afford a Porsche, after all.

"mack" <mackerel@dslextreme.com> wrote in message
news:12ptnqidaufb11c@corp.supernews.com...[color=blue]
>
> "Hachiroku ????" <Trueno@AE86.gts> wrote in message
> news:n0rdh.1025$4p2.783@trndny07...[color=green]
>>
>> But were too embarrassed to ask!
>> # All Porsche engines[/color]
>
> all Porsche engines are interference type?
>
> That would be a VERY expensive belt to have break on you! Glad I can't
> afford a Porsche, after all.[/color]
Gates does not list a replacement timing belt for any vehicles after 1995
model year, and does not list any 911's, suggesting that 911's and
everything after 1995 model year is either chain or gear driven.
--

Ray O
(correct punctuation to reply)

On Fri, 05 Jan 2007 15:29:16 -0800, mack wrote:
[color=blue]
> "Hachiroku ????" <Trueno@AE86.gts> wrote in message
> news:n0rdh.1025$4p2.783@trndny07...[color=green]
>>
>> But were too embarrassed to ask!
>> # All Porsche engines[/color]
>
> all Porsche engines are interference type?[/color]

Yup. So are a fair amount of Toyotas...
[color=blue]
>
> That would be a VERY expensive belt to have break on you! Glad I can't
> afford a Porsche, after all.[/color]

Car companies will tell people belts are quieter and better than
chains, and the next thing you know everybody is going to chains.


ronbon wrote:[color=blue]
> The later 3.5 Nissan has timing chains, my 96 Maxima had them. It is a
> great engine.
> Ron[/color]