Rear main seal replacement from underneath - questions as I go

[p38fighter]

I have the engine jacked up as far as it will go. I am hanging up on the oil pump. I suspect the pickup tube is caught under the windage tray. So does that mean the oil pump has to come off? I can get at the mounting bolts easily and drop it into the pan. BUT how do I deal with remounting it and also making sure the pump drive rod stays in place? Ideas or your experience appreciated. Thanks, Chris

[Eric S]

From what I can remember I removed the screen and its tube (or maybe something else) that bolted on the oil pump. Opened the oil pump when the oil pan was out for checking the internals of the pump.
Nothing fells rom the pump at this stage.
To re-install, I had to have the oil pan close with the screen inside, bolted it up like blinded and then bolted the oil pan.

[jopizz]

Eric is correct. Just remove the two bolts that hold the pickup tube and drop it into the pan. Don't remove the whole pump. You may also have to rotate the engine by hand to clear the counter weights on the crankshaft.

John

[Eric S]

Right, I had to rotate the engine to clear the way...

[simplyconnected]

I don't know how many miles are on your oil pump but don't be afraid to change it after the pan is out. The intermediate shaft should come out with the pump if not, pull it out. That 'spring' goes on top of the shaft so that the shaft stays put if you ever pull the distributor out from the top.

Carefully inspect the pump rotors. The Service Manual uses feeler gauges but I simply look. If the parts are scored or sloppy, change the pump.

Remember, oil (and everything else) goes through the pump FIRST, before oil gets to the filter. I have had metal pieces embedded into the rotors in a 351W pump but it still ran ok.

FE engines tend to idle with extremely low oil pressure. If your pump is 'elderly' I suggest you get a new Melling M57 pump (for $32 at Rock Auto) AND Melling IS60 intermediate shaft (for $9). This is cheap insurance.

If you are using a neoprene-type rear seal, now is the time to pull the rear cap off and replace the seal. If you're using 'rope-type', some of our members use a 'sneaky pete' to pull the new one into the block side. I like neoprene but hey, the rope worked just fine for decades.

After reinstalling the seal and rear cap, put the new pump and shaft in (they go in easily) using blue LocTite on the bolts. Negotiate the cleaned pan* and gasket in place, then bolt the pickup to the pump.
DSCN0948a.jpg
*I go through a ritual when preparing the clean pan:
I use lacquer thinner to clean all mating surfaces. NO oil must remain. I also stick the bolts in a bowl of lacquer thinner to degrease them so the LocTite can work.

I use Permatex Black (RTV) for the whole engine: Spread a THIN coat on the pan, block and both sides of the oil pan gasket. Let it skin over for at least ten minutes before assembly. Since the bolts require very little torque, use Loctite blue on all of them. Be careful not to crush the new oil pan gasket. Torque them evenly (I use a 1/4" ratchet so I don't gorilla them). You want to tighten slightly more than snug. I'll say it this way, if the LocTite wasn't there they would almost fall out by themselves. I hope this helps. - Dave

[Dan Leavens]

Gentlemen great response and suggestions to Chris's situation. I am always amazed at the technical expertise that you our members have, when responding to someone's project not only explanations but pictures. That is why I always say, that squarebirds.org is the " Best TBird site on the planet "

[p38fighter]

The rear main bearing cap is off and shows the following, 1 - it seems oil is escaping primarily under the cap, 2 the side seal got damaged and the expander nail got deformed, 3, (orange circle)there are traces of RTV at the base of the cap side seals. Was there any other portions of the cap which should have got RTV? The seal instructions says - "Apply RTV sealer to the outside edges of the cap recess' in the block." Would that be red edge lines in photo 3? Thanks for the help.

[simplyconnected]

What did the seal look like when you took it out? Let's see some pictures.
The seal-surface of the crankshaft looks awfully dry. Was the seal getting lubrication?
I use just a small dab of Permatex Ultra Black in the bottom corners of the bearing cap because the nails taper at the ends where they don't expand the seals. BTW, stagger the ends of your new neoprene seals so the ends don't match with the block and cap.
DSCN0944.jpg
It's hard to see but here is what my block looks like after the rear seal is in place. You can see a very small amount of sealer on top of the nails.


I usually 'blunt' the ends of the nails before driving them in. Your nail bent because it was too long and it bottomed out, which is another reason why I blunt the point.
Your seals see more oil pressure than your oil pan gasket but not by a lot.

I have a lot more questions. What is your bearing clearance (use a Plastigage). How bad was it leaking?

Are you sure the upper plugs are not leaking at the rear of the block:
RearCamPlugl.jpg

[p38fighter]

Dave,
In order - the seal is a neoprene seal - not rope. The lip faced forward. It was oil covered. The ends were staggered 3/8 inch on installation. It appears that there was no sealer on the nail tops. Plastigage was consistent within a 1000th. The upper plugs were replaced by the machine shop. I have 30 years experience with this machinist. The engine was primed before fire up. We had oil everywhere we could see. All this occurred within the last 3 or 4 months.
Chris

[simplyconnected]

Mechanical failures can be traced back to their cause. I was hoping to see the damaged parts in pictures. If they are not damaged then something worked loose (like perhaps an oil gallery plug). "Oil everywhere", to me means a major problem, not just a drip. - Dave

[p38fighter]

What I meant was that oil was everywhere it was supposed to be. Sorry for misleading.

[p38fighter]

I managed to get this job done. Its a tough one unless you pull the engine or have a lift. Do it on the floor only if you absolutely have to. I used a 6 ton bottle jack on 6X6 blocks (properly braced) and used the pad at the front of the block near the oil filter to lift the engine. When I got the pan off I let the job sit for three days to allow for dripping to stop.
That said I experimented with a few things to try and make it easier. I used lots of assembly lube on the neoprene seal to protect it as it was rolled into the block. And I measured to get the 3/8 recommended offset on both the block and the bearing cap half seals. The roll in was not hard to do but a little nerve racking.
I made guide pins as shown. This allowed me to push the main bearing cap up straight and level into the block. I went slowly making sure the side seals were staying even. Once in it was easy to swap the pins for the bolts one at a time. I used a 1/4 inch nail set to tap in the nails. That prevented the tip from sliding off the nail as it was tapped in.
Getting the oil pick up tube on was a real challenge. I found that if I bolted the bottom hole loosely first I could then push the pan to the driver side and tilt it slightly; this opened up sight space to get the top bolt in. It seemed that trying to do the top one first caused a bind between the windage tray and the tube.

To tighten both bolts I used a flex socket.

I don't think you could do this with big hands. You have to make a contortionist's reach into the pan.
Good luck if you try it.

[Pat in Ma]

Wow, Nice job Chris and excellent idea making the alignment pins from some spare bolts. I sure hope this solves all your leak
problems as you continue to move forward on your project. Hope your out on the road this spring!