Getting ready to try to change the main seal (front) on my 1980 F-150 (300 in line six)

Whats the best way to go about this?

 

I've written it up about 4 times, and really don't want to again. Do a search and read.

 

Pull the radiator out, Remove the belts off the harmonic balancer, pull the center bolt off the balancer, Pull the balancer using a harmonic balancer puller or a three jaw puller.

Pop out the old seal. Clean the bore where it sits with some emery or scotchbrite. Install new seal with a thin butter of permatex on the outer edge and some clean greese on the iner seal lips. Reinstall.

Using a three jaw may damage your harmonic. I have had about 80% succes doing it with them but I have hashed a few over the years.

This aint terribly hard project but it can be a long afternoon on your back.

 

Unless I'm mistaken, the front cover has to come off too. Buy the Felpro kit with the sleeve that goes on dampener. Put in seal with the proper tool or a socket that fits. Use weather strip adhesive to glue o.pan front piece to pan, and let it dry well. Clean it first with something like laquer thinner. Use silicone at edges of gasket, where it meets the old one. Apply silicone in the keep slot on the dampener, and inside where it slides onto crank.

Take a long hard look at your timing gears while you're in there.

 

OK, why does one have to take the timing cover off? Just pull the old seal and install a new one.

 

The seal is pressed in/out from the inside of the cover. It can not be accessed from the outside.

 

Don't do what I did when I used a puller on the harmonic balancer.




The center of the puller is the press that pushes the pulley off. I just put it in the hole on the end of the crank that the bolt came out of. Afterwards, I realized that it had been resting on the threads, and I had completely buggered up the end of the crank. Had to track down a tap to fix the threads. Most parts stores don't carry one that large in stock, so it had to be special ordered.

 

Call me crazy but I am almost certain that I installed mine on my rebuild after the timing cover was on.

I remember using a punch to sink it home. It was a chicago rawhide oil seal, green in color.

 

AB brings up a great point. ALWAYS thread the center bolt back into the end of the crank after taking it out and removing the large washer, Before using a puller to get the balancer off.
Best way to protect the threads in the end of the crank snout......

 

Maybe they changed the cover for some years? Mine is a 75, and I know from experience that the seal is installed from the inside. However, that brings up an interesting point: The seal is pressed against a retaining lip. It certainly would simplify things to remove that lip so the seal could be pressed in w/o having to remove the cover. Of course, then there is nothing stopping it from going in to far or from sitting crooked in the housing.

 

Mine's the same as yours, F-250, installed from the inside. Did it just a month or so ago, so it's fresh in my memory.

 

Yup, AB and F250 are right.
I do it a bit different by using a steering wheel puller to remove the balancer; that way I don't need to remove the radiator. The steering wheel puller is shorter and doesn't need as much space.
One more nit pick- when you go back together, I install the cover loosely and install the balancer to "center" the cover. Pull the balancer, tighten the rest of the bolts, reinstall balancer. You don't HAVE to do it this way, I've just had better success doing it. Don't forget to put a LITTLE sealant around the crank snout and on the washer that holds the balancer on to seal it.

 

All that I have seen had the seal inserted/removed from the inside. I've done these on 69, 73, 75, 78, 82, 84, 89, and 92 model year trucks so that's got the range pretty much covered. You could pop the seal out from the front on the Granada 250 IIRC.

 

Ok, the engine in mine is out of a 92, so it looks like I'll have to wait till summer, when istart working again, and pay someone else to do it. I don't have a shop or garage, so don't have a good place to do it =/