Yaris needing new timing chain after 4 years.

[DMZ]

Originally Posted by brbo

No No, I was referencing DMZ post - not really sure if it was in reference to the issue at hand and how it would apply to the original issue....as he quoted my message....

220mile - sweet you've gotta love that 22R engine, I have a few buddies that pound on them with 36" tires,, I personally do it with my 3B diesel...404km and counting...

My post was an attempt to clarify the fact that timing chains do not stretch. The gears wear and that what results in slack.

It is the same with motorcycle chains. There is a common myth that they stretch with age. If you measure one new and after 50K miles, the length is the same. The sprockets get worn and oval out, hence the need to adjust or tighten it periodically.

Sorry about the confusion. I am inclined to believe that a maintained Yaris should be able to go 400k without having a timing chain issue.

[brbo]

Really,, ok maybe stretch is perhaps too lay - the pins and bushes elongate causing poor mesh with the sprocket - resulting in premature wearing of the sprocket teeth,, culprit chain.... overheat it by lack of lubrication or poor lubrication pins wear chain gets longer...

Don't have acceptable tolerance specs handy,,,

Originally Posted by DMZ

My post was an attempt to clarify the fact that timing chains do not stretch.

[why?]

Originally Posted by DMZ

My post was an attempt to clarify the fact that timing chains do not stretch. The gears wear and that what results in slack.

It is the same with motorcycle chains. There is a common myth that they stretch with age. If you measure one new and after 50K miles, the length is the same. The sprockets get worn and oval out, hence the need to adjust or tighten it periodically.

Sorry about the confusion. I am inclined to believe that a maintained Yaris should be able to go 400k without having a timing chain issue.

they might not stretch like belts, but i bet if you don't change the oil enough and ignore other maintenance items you could get them to weaken and stretch some.