How to set timing?

JMUSINO

MEMBER
1998 TOYOTA RAV4
4 CYL
2WD
AUTOMATIC
370,000 MILES

My timing belt broke while driving. I tried to start the car not knowing the problem and now the crank and cam are out of position. It says to position the crank pully mark on the "0" of the cover and that is TDC. How do you know its at TDC of compression and not exhaust. And same with the cam. How do you know its not 180 in the wring direction?

Tuesday, June 13th, 2023 AT 5:05 PM

3 Replies

CARADIODOC

MECHANIC
34,331 POSTS

You're over-thinking this. When you set the crankshaft sprocket to its alignment mark, number one piston will be at top dead center. Now set the camshaft to its mark. The two are in time.

If you rotate the crankshaft one revolution, the piston will be right back at TDC. If you do that with the belt installed, you'll end up with the camshaft turned one half revolution, coming up on the exhaust stroke, or that 180 degrees you're thinking about. Just rotate the crank another revolution and the cam will be back on the compression stroke.

Do you have the written procedure for this job? If you do not, I can provide that, but I'll need some time to format the many drawings so they can be uploaded. Let me know.

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Tuesday, June 13th, 2023 AT 5:59 PM

JMUSINO