Timing belt replacement: time or mileage?

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Super77

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Lots of great TB info here, but one question not quickly answered: how critical is on-time replacement?

Situation: last full TB/WP was at 90K (dealership, OEM parts). Now at 140k, 15 years after the last service. So, at about half the miles but twice the age. The truck has seen very light duty over this time.

What’s the collective experience here about pushing the clock? I’ve seen timing belts in this same scenario come out of the engine looking brand new. Anything about the 100 that consumes them? Is it possible to check the condition?

And, what consequence if it fails? Are the V8s interference engines?
 
1998-2005 are not interference. Its about $400 in parts if you get the Aisin kit, including the fan bracket. Takes less than a day. I'd recommend getting the parts and doing it when its convenient, but no need to rush.
 
1998-2005 are not interference. Its about $400 in parts if you get the Aisin kit, including the fan bracket. Takes less than a day. I'd recommend getting the parts and doing it when its convenient, but no need to rush.
I’ve successfully done a TB/WP on a EJ253 boxer (09 Subie Outback) and B6-ZE I4 (91 Miata), plus just the WP on my 60-series. None was a V8, but I understand the principles and have the space, tools, and YouTube access. Am I ready to tackle a 2UZ-FE? 😂

It also sounds like worst case on a pre-05: snapped belt = a tow and some inconvenience, not a new engine.
 
The timing belt is NOT a difficult job. With your prior experience it should be no problem on the 2UZ.

Personally, I wouldn't like driving my 100 with a timing belt passed it's prime. The constant unknown condition of the TB would kill the experience. It could be just fine for a few more years...but what if it isn't. The tow home will probably cost more than the Aisin TB kit.
 
OEM belt with low miles last a very long time. My 4runner has 50K miles and 14 years. I have inspected the belt and it is still in very good shape (5VZFE non-interference engine). If the belt is non-OEM, then making to 90 is also risky! My gates belt in the corolla has cracks at 50K miles!

I did my first timing belt job on my LC 2uzfe (non-VVTI are non interference) and it was a breeze. Make sure to route the cam sensor wire behind the fan bracket when installing the fan bracket which also mounts the AC compressor.
The Water pump if OEM should easily last 200K miles, OEM bearings the same! So keep an eye on the belt time to time! Open the driver side timing belt cover..
 
I've done lots of timing belts. The 100 series was one of the easiest. If you've done a subaru then you should have no trouble with this one.
 
Mine goes by 100k intervals but I do that kind of mileage in just a few years. If I were buying a truck that has had little mileage put on it over the span of a long time, like 10+ years, I might opt to change the TB just for peace of mind.
 
Ya dang skippy they can be old but still amazing.... and the coinage savings to boot.
 
Is there trick to the inspection? Typically in my experience the belt tells a better story when you can bend it to expose cracks on the ribbed side. Does the belt’s routing allow this? I think the inspection cover on the cam pulleys only exposes the smooth side of the belt?
 
Passenger side cover is easier to remove. You'll be able to see both sides of the belt - top and bottom of cam pulley, won't be able to bend it much though. Do you have the paperwork for the last timing belt job? To me if it's a Gates or some other off-brand you replace it, if it's OE/genuine or Mitsuboshi and it looks fine you don't. The belt itself is probably the most time/age prone component.

ps - I see it was dealer, had to be OE/genuine, if it looks good you should be fine.
 

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