All Small Six Uh-oh. Found this in my oil pan.

[funkaholik]

I pulled my oil pan to replace a badly leaking pan gasket and when I looked in the bottom of the pan I found these broken metal parts. They are circular and very thin, almost looks like the side flange of a bearing to me.

Anyone know what this is (was?) from these photos? If not I can puzzle it back together and take some pics and measurements.

Looking at my main caps, #5 looks to have side flanges on the bearing, but I don’t see any anywhere else. Also, my main caps are numbered: 1, 2, 3, 4, T, 6, A

WTF?

 

[aussie7mains]

Yes it looks like the thrust bearing cheeks, and the clearance between the remaining bearing is quite high which tells you the other side has disappeared, pull the thrust bearing cap off and take a look. Sometimes there is only the top half of the thrust bearing fitted (Australia did this). You can roll the bearings shells out with the crank in place!

 

[DON]

Just in case… the cap with the T is where the thrust bearing is. The thrust bearing keeps the lateral movement of the crank in check. Before just replacing the thrust bearing, you need to do some checking on why it broke

 

[funkaholik]

I took a photo from a different angle of the cap with the thrust bearing, and it appears that the other side is intact. So if it isn’t the thrust bearing, I wonder what else it could be. I’m going to put the pieces together today and take some measurements.

 

[funkaholik]

@aussie7mains Is it safe to undo just the thrust bearing main cap, check the bearings, and then torque that one cap back on? I thought that crank mains had to be torqued in sequence, starting in the center and working your way out.

 

[drag-200stang]

Maybe you can feel with a wire to feel if it is parts of the bearing that you cannot see.. The bearings are all seated and all mains have been torqued that has been done ,you are not starting to install the crank. I think that it would be just fine to remove the thrust main cap only, just do not turn the crank it if you do not have to at this point to see what is up.
There is a procedure to align the thrust bearing and cap before final torqueing .

 

[drag-200stang]

It almost looks like some shims where crazily used to fix a crank end play issue, watch for that. What is the history of this engine?

 

[Frank]

@aussie7mains Is it safe to undo just the thrust bearing main cap, check the bearings, and then torque that one cap back on? I thought that crank mains had to be torqued in sequence, starting in the center and working your way out.

Any cap can be pulled one at the time. The inner bearing can be "rolled" out of the block without removing any other caps, and new ones rolled in.

 

[CNC-Dude]

It looks like ring lands from the pistons. Perhaps from a previous issue before you got the vehicle and they just didn't clean the oil pan out thoroughly.....

 

[aussie7mains]

@aussie7mains Is it safe to undo just the thrust bearing main cap, check the bearings, and then torque that one cap back on? I thought that crank mains had to be torqued in sequence, starting in the center and working your way out.

Yes, go ahead.

 

[aussie7mains]

It looks like ring lands from the pistons. Perhaps from a previous issue before you got the vehicle and they just didn't clean the oil pan out thoroughly.....

Possible, but unusual for them to get out from the piston, maybe the top half of the thrust bearing, you cant see it from below.

 

[funkaholik]

Well, it is definitely material from the thrust bearing. It looks like outer layer(s) split off and fell into the bottom of the pan. Looking at the crank surface that goes up against this bearing face, I don’t see any irregularities that would obviously cause this problem. What could cause the side of this thrust bearing to delaminate like that?

I am not in a position to turn this car into another paperweight right now. I already have one non-running Mustang project.

So, I know it isn’t the smartest and most complete course of action, but could I roll out the thrust bearing, insert a new one with some assembly lube on it, bolt it back together and fire it up? Or, is there another plan that doesn’t involve pulling the engine?

Any advice appreciated. This is reminiscent of the time we dropped the oil pan in my brother’s ‘69 Z/28 just to change the gasket because it was leaking. Of course, then we noticed there was one broken main bolt, and that started a whole chain of events which led to an entire rebuild. I mean, they were four bolt mains, but we didn’t think having one being a three bolt was OK.

No way am I getting into a full rebuild right now.

 

[DON]

Worst case scenario, put a new bearing in and run it. It would be real good if you could make sure there is end play in the crank. Use a dial indicator to see how much it moves, front to back. I don’t know what the specs are off the top of my head but I can look them up. If you have the end play needed, Run it. What is your oil pressure? Maybe swap out the whole set? It should be stamped on the back: FOMOCO, original. Or what size they are if not original.
These are tough little engines

 

[funkaholik]

Here is the lower thrust bearing. They are FoMoCo, so they are either original (doubt that) or were replaced when these parts were still available from Ford. I believe that the “A” suffix means that they are standard and not oversized. That jives with the measurement I took of the crank journal. Since I have to order the whole set anyway, I’ll look at the other bearings and possibly replace them, too. I’ve never done this with the crank in the car before, but there’s a first time for everything! I’m going to see what I can find about the proper procedure online. Any tips here? I’m especially interested in the best way to get the block side bearing out. I’m assuming I pull one cap at a time, replace the bearing, and then retorque that cap before moving onto the next one. I will use a liberal amount of engine assembly lube. I have the manual here with the end play specifications (0.004-0.008), so I will check those before I run the engine. I guess I should replace the rear main seal while I have the cap off.

I bought this car two months ago, and it was a really good deal. So if I can pull this off, I am ahead of the game. I don’t know anything about the history of this engine, but it looks a little grungy inside, as if oil maintenance schedules weren’t followed that closely.

 

[funkaholik]

Well the YouTube videos I’ve seen have shown everything from tapping the old bearing out with a flat blade screwdriver, to putting a screw in the oil hole of the crank and spinning the crank, using the screw head to force out the old bearing. Am I just over cautious or does that sound like a horrible idea?

 

[hodaka100]

Well the YouTube videos I’ve seen have shown everything from tapping the old bearing out with a flat blade screwdriver, to putting a screw in the oil hole of the crank and spinning the crank, using the screw head to force out the old bearing. Am I just over cautious or does that sound like a horrible idea?

I have not done it before but the screw driver sounds bad and the screw head sounds like a great idea.

 

[aussie7mains]

Well the YouTube videos I’ve seen have shown everything from tapping the old bearing out with a flat blade screwdriver, to putting a screw in the oil hole of the crank and spinning the crank, using the screw head to force out the old bearing. Am I just over cautious or does that sound like a horrible idea?

If you look in some manuals it describes how to do it, basicly you use a split pin, fitted into the oil hole, and turn the crank to rotate the bearing shell out, noting the correct rotation to not foul up the bearing tang. Then fit the new shel the same way. there is another way, if the engine is an auto, (no clutch thrust) if the top half of the bearing is OK and the end float is within spec, just put it back with no thrust on the bottom half. I doubt you can purchase just the thrust bearing on its own. hers a YT post:-https://www.youtube.com/watch?v=DSZiRBYgBNc

 

[hodaka100]

I was going to ask the history... if you just got it, the oil pan looks like it was recently off and cleaned. The engine may have been back yard "rebuilt". Lack of end play is probably what caused this problem. You will need a dial indicator or at the lest feeler gauges to check end play. If there is scoring on the bearing under that cap then it doesn't hurt to pull more caps to check them

 

[funkaholik]

No, I couldn't find just the thrust bearing, so I ordered the whole set. This way, if the rest look suspect, I can replace them too. If all the main bearings look worn out, then I guess the smart thing to do is to check the rod bearings, too. I don't want to go too far down the rabbit hole, but...
I'm hoping that @hodaka100 is correct, and the lack of endplay caused the thrust bearing sides to break, and the rest of the bearings look OK.
Of course, then I need to fix a lack of endplay issue, but it could be that someone didn't follow the proper procedure for seating the thrust bearings and checking endplay. .004 to .007 isn't much to start with.

All I wanted to do was fix my leaking oil pan gasket, but I'm glad I found this before it got worse.

 

[Frank]

Well the YouTube videos I’ve seen have shown everything from tapping the old bearing out with a flat blade screwdriver, to putting a screw in the oil hole of the crank and spinning the crank, using the screw head to force out the old bearing. Am I just over cautious or does that sound like a horrible idea?

Screwdriver is fine just don't ding the crank. I recommend replacing all the mains if you're changing one. Removing one cap at the time IS FINE and is the standard way of rebuilding diesels while still in-frame. I have done several main bearing replacements with the engine in the vehicle, including the '90 f150 and just a few months ago, a '59 Rambler. Purchase the old style tri-metal bearings like are in it, and check the size on the current ones and match it. If standard, go with standard, etc. Look for NOS bearings on ebay. If you can find old Ford, Michigan, Federal Mogal, Clevite, or Sealed Power brand bearings, these are closest to what's in it now.