timing belt 300zx na

[ellyesfairlady]

im changing the timing belt on my 300zx and the crankshaft is not aligned to the spot its supposed to be on, the cams are alinged to the points on the back plate, i was thinking i needed to keep turning the crank with the timing belt in place till i get all 5 dots aligned but the engine locks after a half turn and its not on gear, what should i do?? continue changing the cam seals and not bother aligning the cranck??

[zcar93na]

The marks on the backing plates are just for reference. You need to make sure you have the mark on the crankshaft sprocket lined up with the mark on the oil pump and new belt, and the marks on the cam sprockets ( V-groove on exhaust, punch mark on intake) lined up with the mark on the belt. If it stops turning after 1 1/2 turns that's piston to valve contact, you're a tooth or more off. I know it's aggravating, but take the belt back off and get your marks right. After you for sure get everything lined up, spin the motor over. I turned mine quite a few times to make sure i had it. Oh and after you turn the crank, don't freak out when your marks don't line back up. They don't line back up until MANY revolutions later.

[ThisIsSparTTa]

TRUST ME ON THIS. COUNT. THE. TEETH. "24-45-24-59,and if you care,76 from the crank to the right exhaust cam" http://www.twinturbo.net/nissan/300zx/f ... count.html . I was lazy and thought the crank was close enough, ended up 1 tooth off, caused weird problems, mostly that the engine still ran okay until about 50% load, then would hesitate and stumble big time. Also, I found it easier to count from the passenger side exhaust cam to the crank, than trying to follow it along the passenger side. So, count between the top 4 gears, and then count the 76 down the long side.

[ellyesfairlady]

i still havent removed the timing belt yet, does that mean i should still take of the timing belt and aline the crankshaft to the point that is giving?? and leave the cams alined to the points??

[ellyesfairlady]

thanks for the help though i really appreciate it! i was almost giving up

[zcar93na]

Yes, take the belt off and align the crankshaft to the mark on the oil pump. I know this picture is blurry, but the red dot is where you need to make the dot on the crankshaft sprocket line up. Line up the cam sprockets aligned to the marks on the backing plates, but don't be surprised if you have to move a couple of them. As long as the white lines on the belt line up with the marks on the sprockets, you are good. Like sparTTa said, count the teeth on the belt to double check

**EDIT** You'll have to click on the picture to see the red dot

[ellyesfairlady]

Should the oil seals fit tight on the cams because the top cam (The one with the spring) seal fits tight around but in the center its open

[zcar93na]

Yeah they should be tight, and the hole in the intake cams are for oil to pass through.