Had my timing belt replaced after 10 years and 25,000 miles. The few inches shown in the attached photo pretty much represent what the rest of the belt looks like.

To my inexperienced eye, it looks like it's in pretty good condition.

 

Seems to confirm that the belt condition is mostly dependent on mileage. Age may only play a small role.

I have 58k miles on the original belt which is 9.5 years old. Plan to change it around 80-90k miles. I know some change it early for the peace of mind. It is like insurance. Depending on your risk tolerance you may buy it or not.

 

I'd like to buy it from you and I'll install it when I hit 90,000.

 

Yea I'd say it looks in real good shape - looks almost new. Still changing the TB at 10 years is probably a reasonable plan given the downside of an age related TB failure on that big honking V8 will ruin your whole day.

Thanks for posting the pic - very interesting.

 

Great picture. Gives us an idea that mileage more than time is the factor. Thanks for the post.

 

Wow...very nice...ten years in cold weather climate too, but super ultra low mileage though. Good to know that it's more dependant on mileage than years. Best said earlier: It's like insurance...IMO I'd rather err on the conservative side and not take that gamble. Thanks for the post!

 

I suspect also that Lexus has built a lot of cushion into that 90K mile recommendation. Driving conditions (temperature extremes) and driving style probably factor into it as well. I'm doing mine something in the next month - 90Kmiles on a 2002 Texas car. I'm planning on photographing it's condition to share here as well.

 

I am sure not just Lexus but also other brands build in a lot of room for the timing belt. It is quite rare to encounter a snapped timing belt.

Question is whether there are any signs of an impending timing belt breakage?

 

Here's another data point - a very serviceable belt that I removed from my '02 SC at 38K and 10 years. Although it's not totally visible in the photo, there is perfect detail at the ridge and gullet of each tooth, practically no wear on the drive surfaces. There was slight fraying of the cords at the edges but that was true of the new replacement belt also. In the lower cover there was no buildup of belt particles.

If there is a good method for predicting a timing belt failure I've not heard of it. You could waste a lot of time removing the covers and doing periodic inspections but I'm not sure it would tell you that much and the time or labor could approach that of a replacement. After all the belt is probably good until it slips one tooth. I figured it makes better sense to stick close to the factory recommendations and throw away a perfectly good belt than to be faced with costly engine work for not replacing it at all.

 

Wow more food for thought because I am at 9 years and 28K in my SC..

 

A friend of mine just paid off his 2009 Range Rover Supercharged (HSE size not sport) and paid it in cash from new. Although it's paid off, and it's not driven that much except for his wife to take the kids to school, starbucks runs, tennis lessons around town, etc., he was still carrying very expensive insurance on it with low deductibles. When I asked him why...he simply said, "better to be safe than sorry, the difference between little or no coverage versus full blown coverage definitely doesn't beat the price to replace my $60k RR".

It's all about risk

 

You wouldn't expect a low mileage car to have worn belts unless the pulleys or pully teeth are bad. What you would expect are cracks or belts that are dried out if the belt has gone bad due to age.

 

>cracks or ... dried out ... due to age<

Unfortunately that also happens to guys like me.

 

Agreed. I would think we'll be seeing some pretty decent cog belts coming out of these low mileage '02s. The protected environment where the timing belt runs probably helps preserve it to an extent. In contrast, on the outside of the engine I found the original serpentine belt clearly beginning to crack and deteriorate. I'm sure that it's an over-simplification to compare those two belt types but considering only the texture of the rubber there was a huge difference.

 

My original serpentine on my 02 went out at 4 years and 25k miles. Definitely apples and pineapples comparision, but thank God you can DIY and the part is like $40!