My 2011 rav4 maintenance manual does not mention ever needing to replace the timing chain, why?

Déjà Vu, All Over Again…
Comments From February, 2011, When @nativetexan Asked,
“Do I need to replace a timing chain?”

@Goldwing
"No. You have a timing chain (not a timing belt). The timing chain should last the lifetime of your car."

@mcparadise
"No. You do not need to replace the chain. This is one of the nice things about timing chains; they do not require periodic replacement. The timing chain should last the life of the engine."

@MikeInNH
“Timing chains DO need replacing…but not for at least 250k miles. For some that’s the life of the engine. And one nice things about chains is they will make a lot of noise before they break.”

CSA

I wonder why https://www.rockauto.com/en/catalog/ sells timing chain sets for just about every vehicle?

I mean, if timings chains/guides don’t wear out, why would they list them?

They do wear out…but usually after 250k+ miles. If you keep your vehicle long enough you may eventually end up replacing the chain.

As for why they list them? They list and sell pretty much every part on most vehicles…do you think that all those parts wear out on a regular basis? Probably not.

Before cars had rust protection, the body was usually the first to go. With big V8s the engine usually held up and no one thought about replacing a timing chain. Having had 11 car with timing chains, I have only ever replaced one.

We now have cars routinely getting 300,000 to 400,000 miles out of their engines, timing chains have become an actual replacement item.

It’s a little like medicine. Altzheimer’s is prevalent now partly because people now live longer and we have conquered many of the diseases that felled people at an earlier age. So cancer and Altzheimer’s now loom large.

“Before cars had rust protection, the body was usually the first to go”

That is very true. I can recall a lot of rotted-out rocker panels and fenders after just a few years.
On the other hand, let us not forget that it wasn’t unusual in those days to have to do a valve & ring job on an engine once it reached ~50k miles. Those old engines could go for many more years, as long as you put a few hundred $$ into that type of repair job every 5 years or so, but those few hundred $$ would translate to a few thousand $$ today!

And, let us also not forget that a lot of the old engines used timing gears, instead of timing chains!

We now have cars routinely getting 300,000 to 400,000 miles out of their engines, timing chains have become an actual replacement item.

It’s not just mileage. Like everything designed today, it’s about cost. Nothing is quite as robust as it was back in the day. So you can’t make comparisons about timing chain longevity based simply on the assumption that nothing has actually changed in their materials or design. It’s not apples to apples…

BTW- regarding “plastic” gears, my 1969 Corvette(s) had nylon teeth on timing gears- ostensibly to reduce noise. One one, it disintegrated sometime in the 80s and the bits plugged up the oil intake screen. GM was not the only mfr doing it either. Plastic coating of the gears is not a new(er) idea…

@Docnick
"It’s a little like medicine. Altzheimer’s is prevalent now partly because people now live longer and we have conquered many of the diseases that felled people at an earlier age. So cancer and Altzheimer’s now loom large."

Wow! You reminded me of a Car Talk Puzzler that I heard in 1999.
http://www.cartalk.com/content/world-war-i-puzzler-number?question

Here was Tom and Ray’s answer:
http://www.cartalk.com/content/world-war-i-puzzler-number?answer
CSA

@CSA Yes, you can play with statistics. I once worked for a large company which had a company paper that went to all employees and known retirees. The personnel manager was a good natured person and took his job very seriously.

Over lunch one time I remarked that the company was “working it’s employees to death”. As proof I used the company paper which corporate wide listed all deaths. The average age was well below 65!

After he calmed down I explained that the paper listed all KNOWN retiree deaths as well as those employed, who had a different death frequency but were all under 65… However, few retirees kept the company up to date on their addresses, so there were far more working employee deaths reported than retiree deaths.

A famous politician once summed up statistics as being “like a bikini swimsuit; what they reveal is suggestive, but what they hide is vital”.

@Docnick - I thought the quote was “There’s lies, damned lies, and then statistics”. Another favorite of mine was always “The figures don’t lie, the liars can figure”.

@bloody_knuckles It was Benjamin Disreali, Prime Minister of Great Britain who uttered that famous phrase.
When JFK ran for office his Great Society pitch was that “13 million American children are going to bed hungry each night”. This was based on an obscure nutrition study that US children were not getting the right nutrition for proper growth. It had nothing to do with how wealthy the country was and everything with US mothers being ignorant about what to fed their kids to get proper nutrition balance.

If you visit a supermarket today in a poor neighborhood you’ll see expensive junk food selling well compared to relatively inexpensive nutritional food.

Basically …everything wears out eventually. Machines, humans, be what it may…we are all unfortunately moving into a state of inexorable decline. Need any other good news today ?

Blackbird

If you visit a supermarket today in a poor neighborhood you'll see expensive junk food selling well compared to relatively inexpensive nutritional food.

That’s pretty much every neighborhood.

After 50 years of the war on poverty, we still have millions of kids going to bed hungry. I guess they are different kids though than in the 60’s. I think the point was that the way my grandmother cooked was with the raw ingredients from scratch which are quite cheaper and more nutritious than the processed foods. I think its a lost art. I can still see the beans soaking in the pot. Now we just buy the stuff in the can at our own peril.

Those older Chevy V8s with a nylon gear would do good to last 100K and people around here used to burn up the timing covers on Nissans and Toyotas because of timing component wear,the oil wasnt as good in those days for some reason ,the Isuzus would go through a timing set fairly regularly too ,most mechanic around here accepted the timing chain failures and just replaced them when they started rub against the timing covers, the best fix in those days was replacement with a double row set ,with metal gears ,rather then the Hy vo ,witha plastic (nylon gear )