Replace harmonic balancer on 2005 ford explorer

[gdy]

Hi, I am new to the website. I need to replace the Harmonic Balancer on my 2005 Ford Explorer, 2 wheel drive, 4.0 gas engine. There is some pretty good posts on this website on how to determine if a harmonic balancer is defective and some info on replaceing it. However, there is one thing I am confused about and that concerns getting the engine to TDC and making sure it stays in time. Some posts say to make sure you secure the harmonic balance with some kind of wrench to make sure the engine does not turn when you loosen the bolt securing the harmonic balancer. Other posts say it is not an issue because the harmonic balance has a keyway in it and it can only go in one way. Can someone tell me which is correct? It seems to me that even if the engine turns it shouldn't matter unless it is turned when the harmonic balance is out of the engine.

 

[Rick]

Your best bet would be to ask within one of the threads you've found.

 

[sas ranger]

1. A harmonic balancer does not stop engine vibrations from reaching the rest of the car.
2. The only way to tell if one has slipped is to check for TDC or top dead center and its relationship to the timing mark on the balancer.
a. Pull of the cap and the number one plug
b. With a socket on the harmonic balancer bolt, place your finger over the sparkplug hole and turn the engine over.
c. As you turn the engine over feel for the compression stroke (watch the rotor to confirm you’re on the compression stroke)
d. Once you have confirmed you’re on the compression stroke place a large screw drive into the spark plug hole.
e. Continue to turn the engine over with one hand while holding the screwdriver with the other. As the piston moves up it will force the screwdriver down. When the screwdriver is no longer moving you’re at TDC.
f. Look at the harmonic balance and timing tab on the front engine cover. The timing tab should have a 0 mark on it and this should line up with the mark on your balancer. If you’re only off a couple of degrees you’re okay (The piston has a dwell angle, the point between where it stops going up and starts going down.). If it is off by more then 10* then you have a slipped balancer
Everything that spins has what is known as harmonic vibrations. The purpose of the balancer is to help absorb those vibrations and prevent them from tearing the crank bearings, pistons pins, and cam bearings (through inter-block transmission) apart. Many newer and faster reving four and six cylinder engines are also using a counter rotating shaft to help with the vibrations caused by long chain driven cam systems.