Timing Belt Alignment Marks

[Olie]

Hi guys! Been a long time lurker and finally have something that I can share.

I'm in the middle of changing the timing belt on my '05 Pilot and I can't seem to get the three marks to line up correctly: one on the harmonic balancer and the two on the cam pulleys. I can get them close but not dead nuts on.

1. Here's the harmonic balancer lined up as close as I can get:


•Right cam with the cover on:


•Right cam with the cover off (the alignment marks are circled in red):


2. The right cam aligned perfectly with the cover:


•And with the cover off:


•But the harmonic balancer then isn’t aligned anymore:


Of course the back cam is such a pain to see it’s either aligned or not, depending on how you look at it:




So, is that as good as it gets? Or should they be spot on all the time and there’s no question if they’re aligned or not. Keep in mind this is my sixth time reassembling the belt to see if I can get it better, and this is the closest I’ve got. But if it’s not right, I’ll just have to do it over again.

But I really, REALLY want to know before I start pulling it back apart.


PS: Sorry for the blurry pics.

[2010exl]

That looks to be correct.

Keep in mind that there is no fine adjustment of the belt as far as the timing marks are concerned. The smallest adjustment is one complete tooth on the cam sprocket.

If you look to the tooth next to the cam sprocket timing mark, you will see how far off that one tooth is.

Be sure to rotate the crankshaft 2 revolutions, and slowly bring it back to TDC and verify that the marks are still lined up.

[KKL]

I typically mark the old TB at the alignment marks (crank and cams) BEFORE I take it off. That way I can (i) check the old TB against the new TB with fresh markings, (ii) counting the number of teeth between adjacent alignment marks, (iii) check against the repair manual (some manufacturers, e.g. Subaru, give the spacing down to fraction of a tooth. The check suggested by 2010EXL also works (and if the alignment is off, you have to take the belt off and start over). My procedure might be overly cautious, but it is my approach.

[Olie]

Thank you!

The one thing I wasn't sure about was the balancer's alignment because the gear is so small. I didn't know if that was one tooth width or not. I guess that's what I get for being OCD.

The next time I'm definitely going to mark the old belt before I remove it. I did mark the cam gears and the crank gear but then, because the new belt isn't as stretched, they no longer lined up either. I was getting a half tooth difference on the right cam and a full tooth difference on the left (rear) cam.

On the plus side, I figured out what the battery hold down bolt is supposed to do.

[archie]

Not sure if the pictures are of the old belt or new. Anyway, found that the plastic cover mark for the crank pulley did not seem to line up as well as when checking the crank pulley and the mark on the engine with plastic cover removed. Maybe rotate the engine a few times and see if the marks line up right. Or check with lower plastic cover off. Of course, crankshaft must make two revolutions in order to turn the cam one revolution.

[goneb4u]

looks good, KKL's share is very interesting, will use it on my ridge change in teh spring...thanks.

[rocky]

KKL is right on the money, especially with marking the old TB before removal. Did the same thing to wifey's Volvo last week. It was time after ten years to replace it per Volvo. Everything looked in excellent condition.