Gday fellas need to know how to set timing after head replaceme

If you are referring to the ignition timing, the you connect the timing light into the no 1 spark plug lead. Start the engine and shine the light - which should be flashing - at the front of the engine onto the harmonic balancer. You should be able to see the timing mark on the harmonic balancer, and the scale on the engine you align it to. It may help to mark the harmonic balancer with a small dot of white paint to make it more visible. Adjust the distributor so that the timing mark on the harmonic balancer aligns with the timing mark on the block that the manual tells you to use. Make sure that the idle speed is correct first. However if you have not removed the distributor, then the ignition timing should still be OK. If you are referring to the timing of the camshafts and gears, then you do not use a timing light. Most vehicles have special tools that are installed onto the camshafts and crankshaft which lock them into the correct position so that the timing is correct. If you have replaced all these parts and do not know how to set the timing of them, get help from a mechanic otherwise you will break you engine when you try to start it.

need a harmonic balancer pulley you can rent them at your local auto part store

Duplicate question.

the pin is a line up pin for the balancer it does not hold the 2 together if the balancer is stuck you may have to use a puller to remove it

remove radiator and hoses, remove enough accessory brackets to get to water pump, remove waterpump & harmonic balancer, take timing cover loose,loosen oil pan bolts(take about the first 3-4 completely out and loosen the rest), reinstall harmonic balancer bolt and line up timing marks. cylinder #1 at top dead center and valves for cylinder #1 closed. remove harmonic balancer bolt and remove cam gear bolts and crankshaft gear, install is reverse order..

1.9L the camshaft gear has an arrow bumped up from it's center. This arrow lines up with a dot on the cylander head. A mirror placed in front of the camshaft gear may help see the arrow and dot. The crankshaft mark is a bump up on the washer between the hamonic balancer and the timming belt gear. This bump is lined up with the middle slot of the indicator located right above the crankshaft and between the timingbelt. this mark is tough to see with the harmonic balacer still installed but can be seen with a little mirror. Another way to find TDC for the crank is on the harmonic balacer there is a sensor ring it looks like a gear with a tooth missing. T he sensor ring should be 9 teeth to the left from the space from missing tooth. If one way doesn't line up and the other way does then you need a harmonic balancer.

i have a 1998 caravan my harmonic balancer fell off my qquestion is is there 2 separate keys that hold on the timing gear and the balancer pulley on, i have been to the dodge dealer and they printed me out pics but i still don't know for sure if the timing gear has it's own key or there is just 1 long key that holds both the timing gear and the balancer ......PLEASE HELP

First remove right front tire and support vehicle with a jack stand. Remove splash guard lower portion near the harmonic balancer. Remove all drive belts. First remove the A/C alternator belt. Loosen the 14mm bolt at the front of the belt tenioner and then loosen the tensioner bolt (it is the one that stands out, you use a socket on it.). The power steering adjuster bolt with be gained from the bottom. It has a 12mm bolt head on it. You will break the jamb bolt loose first and then loosen the adjusting bolt. Pull down on the belt the help move it after you've loosened it some.Then remove harmonic balancer bolt (19mm).If the harmonic balancer will not slide off the crankshaft then use a two finger gear puller. Place the harmonic balancer bolt back in the crankshaft but do not tighten it. Leave it about a half inch from being all the way in. Next place the puller onto the harmonic balancer (one finger on each side securely press into the belt groove. The center puller bolt will rest against the harmonic balancer bolt head. Tighten the puller bolt and make sure the harmonice balancer bolt does not turn. The balancer should come off at this point.

Greetings!
Further to Tinkertoys1's note...

Yes, the harmonic balancer is manufactured to only fit on one way.
Now, knowing this, the harmonic balancer has a timing mark set into the outside area of the balancer.

Cheers, Jay