Hi guys,

Recently acquired an XJR. This was supplied with the relevant parts and tools to replace the notorious chain tensioners.

My question is in regards to the cam locking tool. When it is bolted down, with the cam flats up, there is still a little bit of rotational movement in the cams. Only slight, perhaps a degree, but some slight movement nonetheless.

Is this usual or might the cam tools be dubious?

 

I had no movement when I did mine, they should be "locked" in position.

If you haven't already reviewed the process... Tmingi chain and tensioner replacement

 

It’s not uncommon to find that they aren’t 100% lined up. You need to pin the crank as it’s very important to not skip this step. What can cause the cams not to be lined up? Chain stretch, plastic guides on the secondary timing chain tensioners are heavily worn or more so one or more of the plastic slippers on the tensioners are missing.

 

I think what the OP is saying is that when the cam locking tool is bolted down tight, there is still some gap between the top of the camshaft flats and the tool surface. That would have nothing to do with chain stretch or anything else related to the engine, but rather the issue would be the tool itself. Unless you buy the real Jaguar specialty tool, most of us are using a Chinese knock-off of the Jaguar tool set. There could be some variation in the machining of these Chinese tools and too much looseness could present a problem. You have to be able to put I forget what 75 or 100 ft/lbs on the cap screws holding the cam gears and all you've got is just the one side of those flats holding the cams from turning. Being that there is a gap, I'd get my feeler gauges out and measure exactly how much gap on each side of the engine and each cam, then clamp the Chinese tool in my mill and shave an appropriate amount off both legs to close the gap and square it up. Our OP probably doesn't have access to a mill but he could clamp his tool in a bench vice and carefully make the necessary adjustments by hand with a file.

 

I get what you’re saying Phil and I can see what you mean by the cheap timing tools. I personally haven’t any bad luck with the two different sets of cam tools. I am sure there’s more of those out there that I haven’t dealt with. I will still say that the cam flats with crank locked can be out of phasing by stretched chains and what I previously mentioned. I have done dozens of engines that needed the secondary tensioners replaced. This is just my experience of why cam flats aren’t perfectly lined up.