Timing Indicator Issue

That is the harmonic balancer. Do not run the engine, because it may cause damage to the engine internal parts because the engine now has a serious out of balance condition.

The local auto parts store should have the harmonic balancer and the harmonic balancer puller.

You will need to remove the serpentine belt, the fan blade assembly and quite possibly the radiator. The extra clearance gained by removing the radiator makes this a much easier job. The gotcha is that you probably will not be able to remove the radiator unless you remove the fan shroud first. There are just 2 bolts in the top of the fan shroud, but there are some tabs that are on the bottom of the fan shroud. These tabs sit in slotted holes or clips in the lower part of the radiator.

Using a 3/4" socket and long breaker bar, release the tension of the serpentine belt and remove it. Then remove the 2 bolts that hold the fan shroud on place. Once the fan shroud is loose, then slide a large piece of cardboard between the radiator and the fan blades. This helps protect the radiator. If you seriously ding the radiator, you may end up with a leak that requires you to remove the radiator and get it repaired. Next remove the 4 bolts from the fan blade clutch. Then you can lift the fan blades, fan clutch assembly and fan shroud out together. Again, be careful not to ding the radiator.

If you have a 5 speed, put the transmission in 5th gear. If you have an auto trans, someone else will have to suggest something to keep the engine from turning. Use a 15/16” socket, short extension bar and a LOONNGGG breaker bar or ratchet to loosen the harmonic balancer mounting bolt. Remove the bolt and washer, take the washer off the bolt and screw the bolt back into the crankshaft 4-6 turns. Then mount the balancer puller on the harmonic balancer and crank away until the balancer hits the bolt. If you are lucky you may get a balancer puller that has a special round block that fits in the balancer bolt hole and seats up against the crankshaft. This saves using the bolt and having to remove the balancer puller midway in the job to get the bolt out of the way. Be sure to never tighten up the balancer puller main bolt unless you have something in place to prevent it for damaging the threads in the crankshaft. That is the purpose of either putting the balancer bolt back in the crankshaft or using the round thread protector block.


See View: https://www.youtube.com/watch?v=ylyq6Iz5qYk
for some ideas it isn’t for a Mustang, but it will be of some use.

Now that you have it out, smear some Never Seez all the way around on the crankshaft. Then put a dab on the balancer bolt threads and underside of the bolt head. Line the keyway on the crankshaft up with the slot in the balancer hub and press it on. Use the balancer mount bolt to get it seated in place, torque to 70-90 ft./lbs. for final tightening. Put the rest of parts back in place; watch out that you get the fan shroud tabs stuck back in their mount slots on the bottom of the radiator. Take a 5/16" fine thread bolt with the head cut off and thread it into the water pump flange. That will help you line up the fan clutch with the bolts holes in the water pump flange. Then put the fan assembly mount bolts in and take out the 5//16" headless bolt you used as an alignment aid. Make sure that the fan assembly is bolted down tight. Then remove the cardboard from between the fan shroud and radiator and tighten the 2 bolts that hold it in place.