Crankshaft Pulley - Rubber Damper - Dry Rot and Separation [not mine just reporting]

[OwnerCS]

I'm starting to see cases of crankshaft pulley rubber damper dry rot and separation. This one was reported by a FB group user. I see this with older Tacomas (95-96) models that are well beyond 25 years old.

I've experienced these before on other Japanese engines with over 20 years and 250,000 miles. To me, the rubber damper is like any other rubber or plastic component that begins to harden and disintegrate with age. I can usually start to see hairline cracks in the rubber damper part that indicate the rubber became brittle and may soon separate from the pulley.

This is a maintenance item that I try to stay on top of before it becomes a problem. I need to check mine for cracks. I will replace mine at the next timing belt/seal change if I make it that far.

I wouldn't call this a common failure but one that I have seen become more frequent with high mileage vehicles that are over 25 years old.

 

[sr5pickup]

A friend of mine found his this way while doing a timing belt job on his Lx. 280k miles, Florida truck most it’s life. What caught his attention was the timing marks weren’t lining up in relation to the crank and cam gears. Luckily he caught it in time.

 

[flintknapper]

A friend of mine found his this way while doing a timing belt job on his Lx. 280k miles, Florida truck most it’s life. What caught his attention was the timing marks weren’t lining up in relation to the crank and cam gears. Luckily he caught it in time.

That and some folks will try to use a strap/chain wrench to hold the damper when loosening the bolt. They find out the hard way....it is a poor method.

 

[OwnerCS]

That and some folks will try to use a strap/chain wrench to hold the damper when loosening the bolt. They find out the hard way....it is a poor method.

Yep. I use a multi-pin OTC 4754 Stinger tool that works for the crank pulley, timing cams, and AC by changing the pins. Taking the largest pins and buff them down a bit will fit in the crank pulley holes. $59.