Question about the rear cam seal.

[Yellow Truck]

I had the engine mostly assembled when I realized the machinist had put the rear cam plug in backwards (concave rather than convex). To remove it I had to drive it out from one side and did a little damage to the chamfered lip. Being a rookie at this I have no idea what kind of pressures this seal will be exposed to, I realize it is right up at the end of the cam which will be spinning at 1/2 engine rpm, so there may be considerable local oil pressure.

My question - is the Motorcraft diesel silicone good enough or should I consider something else, such as epoxy to complete the seal? Do I need to worry about the new seal (I have the right part) going in too far and taking the endplay out of the cam?

[jayb]

If you have a new cam plug it should stop on a lip in the block, before it comes close to hitting the cam.  The Ford TA-31 diesel sealer should be fine to seal it, because there really shouldn't be much pressure at the plug, but having said that I have had them pop out.  I've put mechanical stops there in the past, drilling and tapping a couple of 8-32 holes on either side of the hole boss and using some short screws and either washers or a strap to keep the plug in place.  Almost nobody does stuff like that, but after you've had one pop out you take precautions...

[blykins]

You'll be fine.  Put some silicone around the lip of the new plug and drive it in.  There's a shoulder that it sits up against, so you can't drive it in too far.  That's the beauty of installing it the correct way, there is a mile of room between the end of the cam and the plug. 

I usually take some silicone and fill in the gap around the plug after you drive it in.  Smooth it out with your finger, wipe off the excess, and you're done. 

[fekbmax]

I noticed on the pond block I have that there are 3 small threaded holes around the outside of the cam plug for some kinda strap or restraining plate. They look factory but I guess could have been done by the previous owner. It's a good idea.

[C6AE]

There is theoretically no oil pressure there. If you notice on your posted image there is a drilled hole through the rear of the cam next to the center drill. (Your cam may have 2 drilled holes) This hole allows all oil pressure in the void between the cam plug and the cam to vent through that drilled hole to the crankcase.

I have drilled and tapped screws into my Pond block, but because of the different expansion rates of steel plug/aluminum bloc. I also made up my own aluminum plug with an o-ring seal

(I have also had a cam plug pop out...)

[Nightmist66]

I put the plug in dry and finish with a multi-purpose epoxy. The multi-purpose epoxy comes off decent with a chisel and chips right off. JB Weld seems to be very difficult to get off later. JMO

[Yellow Truck]

I love this forum.

I was thinking I was ready to put in the bushing, mount the flywheel and clutch and find out if I can get the engine in with the headers on (on the 4WD trucks one header wraps around the engine mount) - but when I put in the new throw out bearing I noticed the points of the clutch fork are worn flat. I think I'll get a new one while I can get at it. New boot and spring while I'm at it. It will slow me down a little but better than having to go back later.

[Yellow Truck]

The fork - C3AZ-7515-C - does not seem available at any price. Will have to use the old one, at least I can get on with the installation.

[66FAIRLANE]

You may be able to build it up with weld and grind/file it back to shape.