Fact vs. Myth timing belts
#1
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Fact vs. Myth timing belts
A while back i posted a thread about Gates rubber saying the t belt life on a ferrari was something like 9 years.
Fact vs. Myth - What is the earliest age, not mileage, AGE a T-belt broke?
Not one that was installed wrong, just plain age?
If you had one that broke or know of one that broke, what was the age and mileage?
Fact vs. Myth - What is the earliest age, not mileage, AGE a T-belt broke?
Not one that was installed wrong, just plain age?
If you had one that broke or know of one that broke, what was the age and mileage?
#2
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Hey;
In the old days, they broke because they were not tough enough. In as little as 10k miles. Most of the time, I think they broke because they were not adjusted often enough.
These days, the belts are so much tougher that they rarely fail anymore. If you have a failure, it is probably due to something else being wrong or failing first.
Modern Causes;
#1 Improper setup
#2 Related component failure.
In the old days, they broke because they were not tough enough. In as little as 10k miles. Most of the time, I think they broke because they were not adjusted often enough.
These days, the belts are so much tougher that they rarely fail anymore. If you have a failure, it is probably due to something else being wrong or failing first.
Modern Causes;
#1 Improper setup
#2 Related component failure.
#3
Race Car
More than 90 percent of the balance belts are installed improperly one way or anotherfrom what I have seen. That is a fact I have seen from over 150 timing/.balance belts I have checked on a 944 and over 100 I have replaced personally. If that is indicative of how people and SHOPS do their timing belt also, I can't imagine how much premature waterpump and belt failure improper installation has caused.
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Hey;
In the old days, they broke because they were not tough enough. In as little as 10k miles. Most of the time, I think they broke because they were not adjusted often enough.
These days, the belts are so much tougher that they rarely fail anymore. If you have a failure, it is probably due to something else being wrong or failing first.
Modern Causes;
#1 Improper setup
#2 Related component failure.
In the old days, they broke because they were not tough enough. In as little as 10k miles. Most of the time, I think they broke because they were not adjusted often enough.
These days, the belts are so much tougher that they rarely fail anymore. If you have a failure, it is probably due to something else being wrong or failing first.
Modern Causes;
#1 Improper setup
#2 Related component failure.
More than 90 percent of the balance belts are installed improperly one way or anotherfrom what I have seen. That is a fact I have seen from over 150 timing/.balance belts I have checked on a 944 and over 100 I have replaced personally. If that is indicative of how people and SHOPS do their timing belt also, I can't imagine how much premature waterpump and belt failure improper installation has caused.
#6
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FWIW when I bought my car there was no record of the timing belt being changed (it probably had been but I wasn't sure)...the car had been sitting outside for 6 years.
It started up fine, drove it a short distance home, and the belt worked just fine for a few weeks until the headgasket blew. Car had 66,XXX miles on it.
It started up fine, drove it a short distance home, and the belt worked just fine for a few weeks until the headgasket blew. Car had 66,XXX miles on it.
#7
Race Car
I really never trust any paperwork even if they have changed the belt. If you don't change your own belts, take it to a shop where you can truly trust their work. One of the main reasons why I changed so many belts is because I pretty much change every T belt of every 944 I buy that I don't take apart.
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#8
Race Director
The truth is belts are cheap and if you can do it yourself not that hard to do considering the worst case result. As such it is always good to do the belts on a newly purchased car. The exception is you have good documentation and know the car has been well taken care of. If there is ANY doubt it makes sense to do it.
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I agree, anecdotes are not going to help much since (I feel) the early death of some timing belts is due to installation problems, overtensioning, roller issues, lack of retensioning, etc.
Skipping the retensions is probably really hard on the belt with all that flapping around.
-Joel.
Skipping the retensions is probably really hard on the belt with all that flapping around.
-Joel.
#10
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Case in point: one car I bought had records of the belt(s) replaced prior to purchase. However, the BS belt failed on the car sometime later. After inspecting the failed belt, it was obvious it was the original belt, only the cam/timing belt was replaced when the car had been serviced. Dont trust sellers or repair receipts.
For what its worth, the original BS belt lasted 11 years, 85k miles.
Tom, a 2-3 year old t-belt w/ 10k miles is fine w/ lots of life left. Not a reason to deduct value of a for sale car.
For what its worth, the original BS belt lasted 11 years, 85k miles.
Tom, a 2-3 year old t-belt w/ 10k miles is fine w/ lots of life left. Not a reason to deduct value of a for sale car.
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Case in point: one car I bought had records of the belt(s) replaced prior to purchase. However, the BS belt failed on the car sometime later. After inspecting the failed belt, it was obvious it was the original belt, only the cam/timing belt was replaced when the car had been serviced. Dont trust sellers or repair receipts.
For what its worth, the original BS belt lasted 11 years, 85k miles.
Tom, a 2-3 year old t-belt w/ 10k miles is fine w/ lots of life left. Not a reason to deduct value of a for sale car.
For what its worth, the original BS belt lasted 11 years, 85k miles.
Tom, a 2-3 year old t-belt w/ 10k miles is fine w/ lots of life left. Not a reason to deduct value of a for sale car.
on the other hand, in 03 i looked at a 86 NA with just under 50K miles and the owner who had the car at least ten years told me he never changed the belts. I showed him the receipts for the belts on my then freshly stolen S2 and incorporated new belts and wp in my offer.
So how old regardless of miles should "belts" be changed?
#12
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I always had a question about the 90° rule. When they say tension until the belt can be turned 90°, does that mean easily? Or that's is as far as you can possibly turn it with finger force?
And Clarks says to turn the timing tensioner CCW, but it has always made sense to me to turn it CW. Any input here?
This is all on my early belt setup with no spring tensioner.
Thanks
-Brett
And Clarks says to turn the timing tensioner CCW, but it has always made sense to me to turn it CW. Any input here?
This is all on my early belt setup with no spring tensioner.
Thanks
-Brett
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I bought a 924S in 1997 with no belt maintenance history, and by the condition of the car I can assume it had been quite a while. Car sat for another year before I needed it and I put 60,000 miles on it until the belt broke in 2002. So probably 6+ years and 80,000+ miles is my experience. I change belts more frequently now.
I use the 90 degree method to tension belts and I give it a reasonable amount of finger force turning it 90 degrees. It is a feel thing and if it feels like its not going past 90 degrees without putting my arm into it then I am done.
I use the 90 degree method to tension belts and I give it a reasonable amount of finger force turning it 90 degrees. It is a feel thing and if it feels like its not going past 90 degrees without putting my arm into it then I am done.
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Also..... based on the many 944's that have passed my way, they can wear down with age, as much as mileage. Case in point. A belt with 5 or 10K that is 5ys old, is a lot more dangerous than a belt that is a year old with 15K on it. I have pulled belts off of cars that have been sitting for long periods (more than a couple of yrs), and when you lay the belt down, it is still shaped like it was still on the car!! In other words, the belt had become brittle.