Timing belt tdc

Bruiser

Image description

So about to replace belt on 78 245. With old one still on when crank turned to line up with 0 the rotor isn't pointing to no.1 cylinder. Can I just remove old belt and turn cam to line up notch on valve cover and should that get rotor to point to no.1 cylinder?

ramrod

As long as crank pulley mark and cam pulley mark are aligned, position of distributor rotor is irrelevant

If you have the camshaft not meeting with the mark on the cam cover it won’t align number one on the distributor

carnut222

You may just need to rotate the crank 360 degrees…what spark plug lead is the distributor rotor pointing to in your photo? It will be off by about 10 degrees due to the timing advance/retard. Main thing is to align all three pulley marks (crankshaft, camshaft and intermediate shaft) once you've removed the timing belt, before installing the new timing belt.

VolvoHordz

Don't worry about the lines on the timing belt cover. Just take the timing cover off and turn the motor over until all the lines for the crank, intermediate and camshaft line up with there respective marks.

With the marks lined up, the distributor rotor should line up more or less with a line on the distributor housing (just lift the plastic disc slightly to see it). Well at least I think there is a mark with that ignition system…

The distributor needs to also be phased correctly with the intermediate shaft. I have seen it in the past where someone has changed the phasing to 'fix' the intermediate shaft not being timed right.

If required, changing the phasing of the distributor is as simple as unbolting it, lifting it up and turning it slightly before reinserting Though they can get pretty seized up tight with the block.

dmc

a little further info, the distributor will be at cylinder no. 1 or no. 4 with crank at tdc.

the cam will have its marks align (at the top) only when distributor is at no.1 (spins at half crank speed)

the intermediate shaft should line up when the cam does. best not disregard this.

some timing belts have lines drawn on them to make it easier to line everything up.

a 3mm allen key is also handy for the tensioner. compress the tensioner with a bench vice and slot the allen key in. a qik-grip will also work if you are careful, they can pop out.

pull the allen key out when it is all back together and tighten it up. i always turn it over twice and check the marks again.

the block on the pics looks clean, if necessary do crank and cam/int shaft seals while you have everything apart.

Bruiser

dmc Is it advisable to remove old belt then individually turn cam and intermediate until both line up then put new belt on?

ramrod

It’s good practice to time the engine to TDC #1 before removing the belt that way the new belt goes on without any of the pulleys turning but you should always triple check your marks regardless