For those of you that are always asking how long a timing belt will actually last, here is some info.

I changed my timing belt two weeks ago on my 2002 4Runner 3.4L Auto (Belt had 92 000 miles on it and was 6 years old). The old belt was in good shape, but due to be replaced based on mileage.

Yesterday, I changed my buddy's timing belt on his 1999 Tacoma 3.4L Auto (Belt had 94 000 miles on it and was 9 years old). The old belt had numerous micro cracks all over the back side (non-ribbed side). The cracks ran across the belt like you would expect (and not along the length of the belt), and ranged from 1/8 to 1/4 inch in length. I would assume that his belt was on it's last legs.

For those of you that have actually suffered a broken timing belt, how badly was it cracked on the back side (not only where it broke, obviously... but on the rest of the belt?)

 

isn't it supposed to be replaced at 60,000 miles (100,000 km)?

at least that's what toyota recommends for jdm 3rd gens 4Runners (petrol and diesel).

 

I had a beater corolla that had similar cracks as your buddy's, I drove it like that for another 32,000miles(about 14months) before it let go and bent the valves, I didn't care because it was just a $500 commuter car, it wasn't worth the down-time to fix it.

 

3rd gens are at every 90K miles.

 

Good info. Thanks. Luckily, Toyota 4Runner 3.0L and 3.4L engines are non-interference engines, so no worries about bending valves, but being stranded on the side of the road is no fun either.

 

Yep... 90,000 miles.

 

Yeah, especially in winter up here where temps can often be -20 or less.

 

Ha... Yeah. Even more reason not to skip this maintenance.

 

I figured at -20 that would be a good reason to skip it. :-)

I changed the belt in mine when it has about 140k on the clock. I have no information that it had ever been changed before though.

 

im at 150K ('02)and am also curious as to how the original belt is gonna look when i finally change it...