[ds968]

I have an old tread here somewhere on the forum , but no way to revive it .. so here’s a new one . 

The last timing belt I purchased and installed was the Gates High Performance one ( as opposed to their “regular”  timing belt ) .  I wrote to, as well as spoken to Gates at that time , and they asserted this particular belt has a safe longevity of 100,000 miles, OR, 25 years + , whichever comes first .    I had this belt installed in 2019, and only put about 10 K miles on it since .  Do I take their word for it and not worry about replacing the belt until it reaches those thresholds, or plan to change it at, say, a ten year interval,  regardless of mileage ? 

Of course Gates does not warranty the belt for what the state is the mileage and time durability is, so it’s just their guideline …    What do you guys think ? 

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[unknown4u]

Since I owned the car I always changed it every 5 years. Always it looks like new. But I saw the the hydraulic tensioner has have a small cleareance what causes a roller that is a little bit offline. I always clean the total area from dust and rubber particals. After 5 years, still the belt looks new there is always a lot of rubber parts that comes loose from the belt. The last time I chanched the belt I also fitted a new bearing in the arm from the hydraulic tensionar with a new axle. Last summer I retensioned the secundairy belt and I saw there was no dust or so ever in this area. My advise is pull the cover and inspect with an endoscope for dust etc. Than make a decision. In my case when al is still clean than I will last it for a year longer and inspect again. I have a dayco timingbelt

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[ds968]

Thanks, that’s a good suggestion . Will do.    My understanding is that Dayco belts are also excellent .  Although this is hearsay,  Continental belts are of lesser quality ( or at least used to be many years ago ) and carry a higher risk.   My first belt was a Conti, and it broke apart right around the 60k miles mark .   And five years .   Ironically I had a scheduled appointment to replace it the week after it snapped .    :angry2:  :whine:

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[vliegwielolaf1234]

Was it the timing belt  , because i have seen a few 944's mainly with broken balance shaft belts wraped around the crankpully , and my guess with the broken drive belt ones ,it  might have beemnthe balanceshaft belt taking out the drive belt .

 

So i swap them on time , and not taking any risk .

 

I don't see an advantage with the stronger gates belt , since they don't sell a balanceshaftbelt with the same stronger specs !

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[ds968]

Yes, the balance belt was intact and in its place .   At one time Gates did sell the Kevlar reinforced balance belts also, but I don’t see them available any more .. I’ve read that balance belts tend to come loose and take out the timing belts,  maybe I’ll just have the shop take the cover off and inspect everything meticulously ; condition or both belts , tension, teeth , etc.    Worth the price for peace of mind ..

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[Ryan]

Call California Psychics.  I am sure they will know. :glare:  

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[ds968]

Call California Psychics.  I am sure they will know. :glare:  

Same psychics who predicted Kim Kardashian will pass  the bar the second time she takes it ?    Oops , guess all three missed that prediction 

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[ds968]

So just for some peace of mind , I’m taking the car to the shop to have them take a look at whatever segments of the belts they can check with a high definition borescope camera they have .   They can open the cover a little bit , just enough to get the camera in there and check it out . Yes, it’s no way near the same as inspecting them comprehensively, for pliability, etc ., but they said if the segment they check looks good ( no surface signs of cracking at all,  intact teeth, etc . there is a 99% chance the rest of the belts are in the same shape .   I’ve had this done once before at my previous mechanic’s shop . 

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[Kim]

just remember that 69% of all statistics are made up.

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[ds968]

just remember that 69% of all statistics are made up.

and the other 31% use the 69% ones as a baseline 

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[ds968]

Had the belts inspected with a high definition borescope  by the Porsche shop.   They said that the belts top and bottom , sides, etc . of both the timing belt and balance belt look brand new . Not the slightest sign of wear , not any hairline marks on them , nothing !   I expected that , it’s been only about 10-K miles on it , and under 7 years .   The latter ( years are almost insignificant ) belt degradation is 99 % mileage and 1% time.  According to Gates and Dayco .   See my original post re what Gates asserted regarding their high performance “racing” belts which have a Kevlar composition as part of the belt construction.    

So at least , based on appearance , I  have a high degree of confidence these are essentially good for another 80k to 90k miles and another 15-20 years , whichever comes first  .  But I’ll probably replace them in another 50k miles or ten years , just for safe measure. 

I could be wrong , but I’m willing to take that risk .   

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[Cloud9...68]

I think the quality of timing and balance shaft belts has improved significantly in recent years, so you're probably safe going well beyond the historically understood change interval.

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[ds968]

I think the quality of timing and balance shaft belts has improved significantly in recent years, so you're probably safe going well beyond the historically understood change interval.

Agreed . And that’s the case with even “ regular “ belts ,  the racing ones from Gates are exponentially better .   I have done an insane amount of research on this , mostly because I have experienced a broken belt which at the time resulted in a $ 5,000 repair bill ( and that was from an independent mechanic, the dealer quoted almost $ 11,000 ! ). I’d be willing to bet that now both of those costs would be double .   And that’s if by miracle you can find 968 valves and all the other parts needed.  If the break results in damage to pistons and/of cylinders, a distinct possibility , forget about a fix, no matter how much it costs , unless you find a totaled 968 with an intact engine you can buy. 

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[Inkedupfatboy]

Porsche shops here told me they wouldn't work on my car when I bought it and that included Brumos.

Nice huh?

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[ds968]

Porsche shops here told me they wouldn't work on my car when I bought it and that included Brumos.

Nice huh?

I found one shop close to me whose other business is developing and building race engines and race cars for BMWs, and Porsches .  They also do general maintenance for BMWs, Porsches , Audis , and Mercedes .    They’ve never seen a 968 but said they’re confident they can fix anything on it .  The only issue ; they don’t have a diagnostic instrument for a car this old . So far they did not need if because they identified the issues based on their knowledge and intuition .  For that matter the Porsche dealer whose repair shop also specializes in vintage Porsches, does not have a diagnostic tool for anything that’s not 2000 and younger . .  Just not 968s.   So I have to upgrade my old Durametric software which no longer works , with another software.   

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