JDBob62

I know it is said many places that the rear main oil seal can be replaced with the crank installed.

What are the tips from those who have done it?

I have the oil pump off and bottom bearing cap removed. Do I have to also at least loosen the other bearing caps?

Instructions say to tap the upper seal half around and out. What are the tricks to break it loose from the block?

DZAUTO

You are correct, that is what the instructions say-----------------!!!!

I've done several (and I see a lot of flack coming). Here is what I found that seems to help----------ESPECIALLY getting the upper half to bust loose from up in the block. COMPLETELY loosen all the main caps (CAREFUL, not so much up at the front cap, because then the weight of the crank rests on the front seal!!!!). I like to use a VERY small, thin screwdriver to break each side of the upper seal loose from the groove in the block. Next, if you have some long, skinny needle nose pliers, grasp the seal and gently, gently work it down, constantly being careful not to scratch the seal journal of the crank.
When you install the new upper half, don't push it all the way around the crank. Leave about 3/16-1/4in of one side of the upper seal hanging down and do the same for the lower half in the rear cap. This staggers the joints of the seal halves so that they are NOT indexed with the mating surfaces of the cap/block.
Torque the caps, put it all back together.
Of course, you'll be installing a new pan gasket. I LOVE the 1-piece pan gaskets from Felpro. The instructions say NOT to use any sealer with the 1-piece pan gasket. I've had small leaks at the corners, and by applying a small amount of RTV (such as the Ultra Copper), this has been a permanent cure.

Tom Parsons

70vert

I've done a couple. The old upper can sometimes be a bugger to get out. I found that an old oil dipstick, sharpened on one side, makes an ideal putty knife. There is also a tool made for stuck seals, which is basically an extruded aluminum piece of the same profile as the seal that is used to push the seal out. Otherwise read and follow the shop maunual.

John

63 340HP

I have always had to loosen the other main caps, slightly, 1/32 (more in back and less up front). It allows the crank to slightly drop and take the crush off the upper half of the rope seal. You do not want to drop it too far up front, as it can damage the front seal.

Removing the upper main seal can be frustrating.

You may get lucky and tap the seal out. Use a brass or nylon drift (to prevent nicks on the journal) and gently try driving one end of the seal to run it up one side of the seat and out the other side.

If the seal fails to budge, carefully run a screw into one side of the seal. Use a long shank screwdriver and drive it by hand, to prevent slipping and to feel how the screw seats (I wrap the screwdriver shank with electrical tape to prevent the potential to mar the journal if I slip). Use needle-nose vice-grips on the screw and pull the screw & seal on one end, while you use the drift to push on the other end.

Do not pull the seal all the way out, keep it half-way out until you are ready to push in the new seal. The old seal maintains the clearance between the crank and seal's seat groove, and makes it easier to push in the new seal.

Prep the new seal with a light coating of Vasoline or other light lubricant. Once you have the new seal half-way around the journal, push it in while pulling the old seal out. Allow the new seal to follow the old seal out (it helps).

With the seal installed, use a single edge razor blade or Exacto-knife to trim the seal ends nearly flush with the cap & groove. Trim around the edges to prevent any seal "hairs" from getting caught under the cap as it is tightened. Don't worry too much about a rough texture with longer "hairs" in the center of the seal ends, these will crush together and help the ends of the seal to mate and mesh. In the old days the seal was ready to go with a dab of grease on the ends, and many builders these days add a drop of silicone on the seal ends (I do not, and never had a problem).

Loosely fit the cap, and check for alignment. Go back to the other main journals and tighten them first, and try to run each of the other main caps up into the block with the same torque and clearance to evenly seat the crankshaft. When all the other main caps are snug, then go back to the rear main and run it up snug.

Test your torque wrench a few times against another wrench to get it working (what is needed for most "click" type torque wrenches). If the wrench is good, torque the caps down in steps (I always use three steps of torque). Watch the torque ratings for the caps and bolts (they are not always the same).

I was also taught to pull the front main cap for inspection, because it is the last to receive oil (and the first to show wear). If you have the crank lose, you might as well check it out.

This was how my father showed me to pull the rope seal on my Pontiac's, and I have used it many, many, times (including the 327 in my 63').

Good Luck!

PS, in the proof read I caught DZAuto's advice to rotate or stagger the ends of the two seals, to locate the mating ends slightly off of the crank & cap center-line (damn good advice, if you can slip the seals).

JDBob62

Thanks guys. I will follow your advice tomorrow AM and give successful status report in PM

JDBob62

OK, I am at the Frustrating point mentioned earlier.

Just to make sure I am on the same page with everyone else. The engine with transmission attached (PG) are still in the car. I loosen all crank journal bearing caps just enough to get a little movement in the cap (less than 1 turn on the bolt).

If the crank is still mounted to the flywheel and that to the trans, will the crank move any to losen the crush on the top half of the rear main seal?

Does anyone know the name of the seal removal tool and a source mentioned in an earlier reply to this posting?

Thanks and THANK YOU ALL UNIFORMED VETS!

Bob

63 340HP

Go ahead and loosen the main bolts a few turns (more in back as needed). The front snout of the crank would have to drop ~ 3/32nd's before it has the potential to tear the seal (lots of room). Do not be shy about lowering the crank, it has considerable resistance to dropping, with the friction of the pistons and rings holding it in-place.

The torque Converter (TC) bearing slop should allow enough drop to lower the crankshaft and make it easier to pull the seal. If you think the TC is binding the crank you can loosen the bolts that hold it to the flexplate to gain more slop.