Crank Rotation with Cam Chain Tensioner Removed

[St. Hubbins]

I've been perusing this forum occasionally over last year since getting a GS (425L). Lots of good stuff on here.

I pulled the cam chain tensioner out yesterday since I already had the carbs out anyway and figured I should learn how it works and make sure it's working properly. I followed the bwringer guide which was very helpful. I set engine at TDC before doing it. Things is, it looks like the crank moved a little bit during the tensioner removal somehow, either after tension was already off, or while tension was being released. Not much, about the half the distance between the the F and T timing marks, on the order of a few degrees.

I don't have a feel for these things, so I'm not sure if a little bit of crank rotation is enough to merit pulling the cam cover off and checking to make sure no teeth were skipped. Or is that totally unnecessary? I did just adjust the valve clearance last month, so there would really be nothing else I'd need to do while I've got camshaft the cover off.

[chef1366]

If you did not rotate the motor it nature for it to shift removing the tensioner.
Cock the tensioner and install.
Uncock the tensioner and recheck TDC. It should be dead on with the cams.

[St. Hubbins]

If you did not rotate the motor it nature for it to shift removing the tensioner.
Cock the tensioner and install.
Uncock the tensioner and recheck TDC. It should be dead on with the cams.

After reinstalling the tensioner and placing tension back on the chain, the crank didn't return to the original TDC position. So I'm wondering whether I should take the camshaft cover off to investigate, or if it's unlikely that any teeth were skipped. I think I will take the cover off to take a look to be on the conservative side.

[JEEPRUSTY]

Yes err on the side of caution always.

[St. Hubbins]

Yes err on the side of caution always.

I pulled the cover and took a look at the camshaft chain and everything looks good, arrows in right place at TDC and correct chain pin count, so I think I'm good to go. Thanks.

[Steve]

If only one item moves (crank or cam), it will be the one with less resistance.

In the case of removing the tensioner, it appears that the crank was able to move a bit.

When you installed the tensioner, apparently the crank was happy where it was, so the cam moved.

You didn't rotate the crank through a few turns, so there was really no chance for anything to skip a tooth.

.

[St. Hubbins]

If only one item moves (crank or cam), it will be the one with less resistance.

In the case of removing the tensioner, it appears that the crank was able to move a bit.

When you installed the tensioner, apparently the crank was happy where it was, so the cam moved.

You didn't rotate the crank through a few turns, so there was really no chance for anything to skip a tooth.

.

Thanks, this description helps me visualize what was going on.