Upper timing chain tensioner - What am I doing wrong?

XK-Engine
1

I am puzzled by the tensioning of the upper timing chain.

The manual says: to tighten turn the special tool anti-clockwise, but for me, the chain gets tighter when I turn clockwise.

Any idea what I am doing wrong?

Thanks.

2

The eccentric is “flipped” to the other side: not sure it makes a difference.

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3

In the meantime, I went down to the garage and took apart a spare timing chain assembly I have in a box (I should have started with this…).

Indeed, Paul, given the shape of the excentric, it makes no difference. May be it is better if it tightened anticlockise given that the locking nut is tightened clockwise, although that is counterintuitive to me…

Google Photos

4

If you disassembled it you’d see that the shaft on which that tensioner gear rides has a simple symmetrical cam lobe on the end of it. So irrespective of which way you rotate it, the gear will drop and tension the chain. However I’d caution you to pick a direction and stick with it. When I was timing the cams, I decided to experiment with it because for years I’d been just rotating it without a lot of thought. I timed them spot on perfect using the counter clockwise tension method, I tested several times around and each time it was perfect. The tool just slipped right into the cams.

Then I flipped the tensioner over to the right , then spun it over and stopped on TDC. Lo and behold the cams were both off about 3 degrees. I can’t remember which direction. So pick a side and stick with it.

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5

Since you took it apart, do try and clean out that shaft. Mine had a plug in the end. It required some heat to be able to unscrew it, and there was a lot of sludge in there as well as some filings because I had a chain guide come apart.

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