Help! She died today and won't turn over -UPDATE it's a spun bearing (1 Viewer)

gonzopancho

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Just hit the phone and the recommended shop in town said they won't build F's anymore. Too much trouble...Said they'd do the machine work, but won't assemble it. Has me think if these guys won't do it, I sure as hell shouldn't be doing it myself! He said they do a lot of 2F' and have 3 sitting there right now they just wrapped.

Guess I'll call around more but maybe Mark's 2F is back in play after all. 2f with my 3 speed would require less mod than 4 speed and transfer change. Again, I don't hate the 3 speed
If you want to keep the F, lmk and I’ll assemble it for you. No charge, you buy the parts. It’s just going to be getting it to and from ATX that’s the hassle.

Yes, I essentially own a software company now.
 
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If you want to keep the F, lmk and I’ll assemble it for you. No charge, you buy the parts. It’s just going to be getting it to and from ATX that’s the hassle.

Yes, I essentially own a software company now.
I really appreciate that generous offer. You're above and beyond! I think I'm gonna take Marks 2F and get it done here in town and bolt it to what I have. Think I'll keep the original just to have it..Maybe I'll redo it myself if I ever get the drive to.
 

gonzopancho

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If you want to keep the F, lmk and I’ll assemble it for you. No charge, you buy the parts. It’s just going to be getting it to and from ATX that’s the hassle.

Yes, I essentially own a software company now.
Didn’t always though. Back in the late 70s - mid 80s computers weren’t really a big part of my life.

Dad insisted I go to college though.

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Think I'm gonna have some hours after work tonight while the wife is at a work event to start the part pulling and get this removal going. Last we spoke you didn't have a hoist but I think you said you do now? I can buy one at H.F. or craigslist easy enough if not. Once I get to the point of total confusion or ready for a pull, I'm sure I'll take you up on that help with the rig up to the hoist and actual pull. Just not sure about it once I get to that point! They only show you so much on TV ;)
College was mandatory at my house too. So went to Arizona State. I'll show em!
Go Devils! Another ASU grad here…followed my wife to Tempe after a wasted year at the local jr. college.
 

PabloCruise

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So you're cooking along in 3rd (or 4th) gear and .. 65mph. Right? You don't drive your pig faster than 65mph unless your name is @wngrog or you've got something that isn't a F, 2F or 3F in your pig, right? It's a Land Cruiser, not a Land Speed Racer.

Anyway 65mph, 3rd gear, 33" tires, 4.10:1 gears. Call it 2700 rpm.

You've done 65mph for an hour on I-25 because you live in Ft. Colins, but the company called a meeting in Denver. Everything has gotten good and warm. The oil is hot, and has lost some of it's viscosity. You didn't really notice this, since the gauge shows good oil pressure, likely because the oil pump is still pushing enough oil that you're running against the pressure regulator. This is especially true if you've decided to run a 'high viscosity' oil.

Anyway, you exit I-25 and stop after 300 yards, because there is a stoplight at the end of the on-ramp. The oil is still hot, so viscosity is low. The engine is still hot, so while the heat source (your foot in the throttle) is now minimal, there are a couple hundred pounds of cast iron, aluminum, oil and water that are all well over 200F. The oil is thin, and the oil pump isn't turning very fast (you're at idle).

Your FJ55 is from the 70s, (unless you have the rare bird 67-69 vintage). it uses the tech of the era, including the "gauges" which are really indicators, not calibrated pressure meters. No fancy MEMs-based sensors here, it's all analog, with very little in the way of conditioning or protection circuitry. They run on the same 12V that runs your headlights. The 12VDC is supplied to the gauge, while the ground is at the sensor. A current passes through a wire-wound coil mounted within the needle's pivot and produces a magnetic field that moves the needle across the calibrated scale of the gauge. How far across the scale the needle goes - what reading it yields - depends on how much current flows through the gauge. This in turn depends on the resistance of the gauge's return wire which is again, grounded to the engine block through the sensor.

This is why if you managed to touch the wire that goes to the oil pressure sender straight to ground, your gauge will no longer work. The tiny wires in the coil in the gauge were never built to handle the current you just allowed through the gauge, and you now have an open in the coil and the gauge no longer works.

The resistance of the sensor depends on the oil pressure. Oil enters the end of the sensor which is screwed into the engine block and pushes against a diaphragm . The diaphragm moves a wiper inside the sensor which runs up or down a blade of known resistance this blade is connected to the return wire from the gauge. The more the diaphragm moves under pressure, the further down the resistance blade the wiper moves. So the resistance of the sensor varies with oil pressure and the needle of the gauge moves accordingly.

electric-sensor-units.png



If you have an indicator ("idiot") light, then the circuit largely works the same way, except the 'sender' is really a switch. With enough (oil) pressure, it stays open, and the light is not lit.

You've been cruising (cruising, right?) down I-25, with the alternator happily making as many amps as everything in the truck needs, but now you're idling, so there isn't quite as much current available. Voltage drops some, and resistance is up because everything is hot, and that's just how things are. Hot wires and devices have more resistance. This is also true of the oil pressure sender. These things also conspire to show a slightly lower reading on the indicator/gauge.

You have a few 100,000 miles on the engine, so the journal clearances are not like they were when new. This permits a lot more of the oil to pass right back out the main and rod journals. Fortunately, it doesn't take much oil pressure to support the journals at low rpm. 10psi will do it up to about 1,000 rpm. But 10 PSI looks *really low* on a gauge without numbers. I can't find any metrology but I'd bet the FJ40/FJ55 oil pressure indicator shows around 7.5 PSI at the 'L' mark.

Oh, and that 200,000 plus miles have also put a bit of wear on the oil pump, so it's not quite as efficient at idle as it was when new. IDK if replacement vanes are available these days, but one used to be able to turn the non-driven gear over in a straight-6 chevy if you couldn't afford to replace the pump or gears. Check around page 120-121 of the FSM posted earlier. @Cgn1976 will probably want to look the oil pump (and pressure regulator) over while it's all apart.

Back to the oil pressure regulator, which serves as a type of "safety valve" preventing the high pressure oil discharged from the oil pump to rise above a specified value by means of the adjusting valve. When the pressure is "too high" you can wash the bearings, leading to premature wear. Like any other mechanical part, it can wear, and if it fails to properly close, then more oil gets dumped back in the pan, and less is available for the main bearings, and subsequently rod bearings, camshaft bearings, and the rest of the engine.

This is especially true of the 'F' engine, and its oil pressure regulator. There is a pretty good writeup here: Oil Pressure Regulator - http://www.globalsoftware-inc.com/coolerman/fj40/30C.htm

@Cgn1976 probably wants to go through the oil pressure regulator while he has the engine disassembled.
Shoot, it was worth showing up in here just for that!

Thanks Pancho!
-Pablo
 
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Cheap and relativelyh close...

 
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Cheap and relativelyh close...

Thanks for keeping an eye out. Saw this one. Looks like he dropped the price. At this point, I'm pretty committed to taking Mark's local 2F from his 77 and having it rebuilt in town. A little pricey for the rebuild, but with no shipping or transport expenses it'll do.

Also I figured I'm gonna try the new bearing band aid on the current F in there, since it's a 2 month wait to get the rebuild done. Sanded the journal down by hand last night and it looks really good. No dings to be seen. If it goes again before the 2F get's in there, so be it. I consider it worth it just for the experience at this point.
 

bobm

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Thanks for keeping an eye out. Saw this one. Looks like he dropped the price. At this point, I'm pretty committed to taking Mark's local 2F from his 77 and having it rebuilt in town. A little pricey for the rebuild, but with no shipping or transport expenses it'll do.

Also I figured I'm gonna try the new bearing band aid on the current F in there, since it's a 2 month wait to get the rebuild done. Sanded the journal down by hand last night and it looks really good. No dings to be seen. If it goes again before the 2F get's in there, so be it. I consider it worth it just for the experience at this point.
Keep on track!! You're headed the right way in my opinion 😉 😏 😌🙂 😊
 

Zjohnsonua

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The bearing material is obviously markedly softer than the crank's steel, so it should've given up the fight long before any damage was done by sanding. If you're bright and smooth, you're likely good to go. Get the works medical-clean, and be careful to not get debris behind the bearing during install.

Has it been determined what killed the first #4 bearing?
 
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I’m happy for you that that journal cleaned up roll a new set of mains and Conrad’s bearings back in.
 
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The bearing material is obviously markedly softer than the crank's steel, so it should've given up the fight long before any damage was done by sanding. If you're bright and smooth, you're likely good to go. Get the works medical-clean, and be careful to not get debris behind the bearing during install.

Has it been determined what killed the first #4 bearing?
It looks like it's gonna work for the short term at least. Not sure what actually caused this failure yet. There was oil on the bearings and crank when I pulled them, so doesn't look like a total blockage issue there, but I won't really know for sure since I'm gonna fix this, button it back up and run it till the 2F is ready. I'll dig into the oil pump a little before I do that. I'm committed to the new motor and have no plans for this one other than to hold it just to have the original motor. Maybe someday I'll rebuilt it, although realistically, I doubt it if the 2F works out like it should.

Obviously something caused the failure. Thinking back to the day it happened again, it was a perfect day out so I don't think I let it warm up quite as much like I usually do, and then I have slight hill I run down for about a mile out of my neighborhood, where I can either leave it in 2nd or drop to 3rd, or sometimes I'll even just pull it out of gear and coast. I think I left it in 2nd, so maybe it not being fully warm and at a higher RPM, and the slightly low oil level was a bad combo on a bearing that had some wear already?

Regardless, I'm gonna see if I can get it going again with the bearing and if it makes it till I get the new engine in, great. If not, I'll know there's probably an oiling issue
 
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What size bearing set did you get and which manufacturer? I skimmed and did not see it in the thread. I'm assuming you are only replacing the failed bearing and not the full set, correct? Just curious, thanks
 
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Are you using the stock gage cluster for oil pressure, or do you have a real gauge? Maybe the pressure was dipping when your engine oil is warm. You came from a higher RPM and went to idle at the intersection. The other thing is loss of viscosity in the oil. A carburetor seat leaking by and slowly dumping fuel down into the oil pan. Might have been to thin for the engine temp. If the engine was rebuilt and not checking clearances with plastigage, to close. Mixing and main caps between engines, improper line bore. You can plastigage them when you install the new bearings to check clearance.
 
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Are you using the stock gage cluster for oil pressure, or do you have a real gauge? Maybe the pressure was dipping when your engine oil is warm. You came from a higher RPM and went to idle at the intersection. The other thing is loss of viscosity in the oil. A carburetor seat leaking by and slowly dumping fuel down into the oil pan. Might have been to thin for the engine temp. If the engine was rebuilt and not checking clearances with plastigage, to close. Mixing and main caps between engines, improper line bore. You can plastigage them when you install the new bearings to check clearance.
It's hard to know because I just don't have history on the engine. Stock oil gauge. New carb seat and gasket about 1000 miles ago, and new oil about then too. Might have to put a real gauge in there with the engine swap, just for good measure.
 

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