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

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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
Well, again I don't have much info or experience here and since I'm just going the band aid route for a few months without pulling the motor, I bought a cheap set of Federal Moguls off ebay that appeared to be one step up oversize (6785m .25mm). I figured for $30 I'll put it in and plasti-gauge it. If it's not gonna work, at least then I'll have a measurement baseline to work off of and I'll just flip the bearings back on ebay for what I paid or eat the $30. I don't have a micrometer; only a manual caliper , but even if I did I don't think I'd be able to get a crank measurement with it in the motor. I tried measuring the thickness of the current bearing in the good sections that didn't fail, and it looks to be 2.5mm. I'm not experienced and couldn't find much out about bearing sizing without just getting confused and that 2.5 mm number didn't match up with anything I could find....so again, I'll try these and see how far off they are and then I'll know what size to get in relation to these because I'll know how much the clearance is out of spec. Probably could have gotten some help here on this but got ahead of myself and just jumped in.
 

whitey45

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Bearing shell should have the size on it. If its destroyed pull another cap to see if you have standard or oversized bearings, crucial that you have the correct clearance. Usually if there are no size stamped its original standard size.
 
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Bearing shell should have the size on it. If its destroyed pull another cap to see if you have standard or oversized bearings, crucial that you have the correct clearance. Usually if there are no size stamped its original standard size.
I looked for that and didn't see anything helpful. I'll post images in a second from my phone. That said, I guessed they weren't stock and likely things had been done before, hence the try for something a bit over.
 
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When was the last oil change?
If you still have the filter that was on when this event took place, maybe should cut it open and check the pleats and see if there’s any metal in there.
About 1000 miles ago. The one from that is long gone, but was planning to on the one in there now. I still have the oil I drained from this go round, so I suppose I could sift through that again. I also figured I'd do a double change when I refilled it after the band aid...meaning fill it, run it through the system for a few minutes with the fresh oil, then drain and change again with fresh.
 

gonzopancho

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  1. The bearings are “fit”, you need plastigauge to set the shims under the main cap. See the engine manual posted upthread.
  2. Be sure to check the thrust clearance (if possible with the block still in the truck)
  3. Check the pressure relief valve. If it stuck open, then insufficient oil pressure is the direct result. See the engine manual.
 

whitey45

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Shims under the main cap? Thats old school 50’s 60’s factory stuff. No way you have shims in an f engine from the 70’s? Plastigauge new bearings and fit the correct bearing size or grind the crank..
 

gonzopancho

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I appreciate the post. I have the manual and have since the week I got the truck, thanks to MUD and some PDFs'. I also have a Haynes. I've looked all the pages you posted. I'm doing my best to process all of this, but this is the first time I've ever looked at or tried to really process anything remotely like this and I'm more of an experiential learner when it comes to hands on stuff. I realize it's old hat to a lot of you and truly appreciate all the help.

I also realize what I'm doing patching this engine up just to see if I can do it until I get the other one built probably doesn't make a lot of sense, but where I'm at, I've already moved on from this engine. I'm essentially playing with it and don't really care so much how it turns out long term. That said, I think I can get it to run until the 2F gets done, probably sometime near years end. In the mean time I'm learning a ton and trying to soak this all up. If it dies again the day I get it going again, so be it... lol

There are in fact Toyota labeled shims under the main caps. I have no idea if they are factory or not, again because I have no history on the motor. I noticed a set for sale somewhere while searching for bearings. I was planning to just re-use these ones. I read the section posted above and watched a few youtube videos about how to use plastiguage. Without knowing what the size of the bearings I have are, I bought the ones I guessed might be right and with those in, I will have a baseline size I know. I'll use some plastigauge to tell me what the clearance (within the limits of plastigauge) is with those. If I need bigger or smaller and by approximately how much, I ought to be able to an educated decision about what the right size is, or at least that's the plan. Not ideal but I can't find anything on the bearings that came out of it and I haven't seen anybody post anything based on the pictures, and a web search on those numbers turned up a goose egg.

I'll check the relief valve. Good to know! I was gonna dig into the pump intake and pump mechanism too and looks for clogs and obstructions.
 

PabloCruise

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When was the last oil change?
If you still have the filter that was on when this event took place, maybe should cut it open and check the pleats and see if there’s any metal in there.

About 1000 miles ago. The one from that is long gone, but was planning to on the one in there now. I still have the oil I drained from this go round, so I suppose I could sift through that again. I also figured I'd do a double change when I refilled it after the band aid...meaning fill it, run it through the system for a few minutes with the fresh oil, then drain and change again with fresh.

Do you know what viscosity oil was in the engine?
 

gonzopancho

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There are in fact Toyota labeled shims under the main caps. I have no idea if they are factory or not, again because I have no history on the motor.

See?

I was planning to just re-use these ones.

Do this. Should be fine assuming you get the right size bearings.
 

gonzopancho

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Followed some MUD threads and ended up with Shell Rotella T4 15W40 and used the ZDDP additive recommended. Good, bad, way off?

Folks like Rotella T4 because of the zinc levels. It’s good stuff. I run Rotella T6 in the 2008 Ford and will run T4 in the 1HD-FT and FTE engines.

Remember that the ZDDP tribofilms only form under heat and pressure / sheer. Cold and/or new oil doesn’t present these conditions.

Anyway, if you used the additive and let the engine warm up, you did all you could for the cam lobes and lifters/followers. Even then, if a follower stops turning, the lifter and lobe will enter an “advanced wear” state. There is a micro-fine taper to all flat tappet lobes that causes the lifters to spin. This is the primary wear reduction strategy. Once that taper is lost, the jig is up. Doesn’t matter how much zinc you have in the oil.
 

gonzopancho

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This was a factory method, (from the factory 50 years ago, things have changed!

Yes, things have changed (I was 10 years old in 1972), but the machining on @Cgn1976’s F engine has not.

This is about two things: oil clearance and bearing “crush”. Early engine manufacturing at volume didn’t rely on precision machining. Line boring and line honing were relatively expensive operations in terms of time, so the engines were “fit” by skilled technicians.

Bearing crush wasn’t really accomplishable, so the upper and lower bearing halves were held in-place by dowels. Later the rods and mains got anti-rotate tabs, so the bearings could be changed with the crankshaft still in the block.

The F engine has these tabs.

Anyway, bearing crush and oil clearance are why the Plastigauge procedure is documented.

Before Plastigauge, a small piece of .002" shim stock was placed between the lower main bearing shell and the crankshaft, the cap was torqued, and the flywheel was given a firm tug. If the crankshaft turned freely, a shim was removed. Once the crank turned with a moderate drag, the clearance was assumed to be .002" and the procedure was repeated for the rest of the main bearings. Babbit rods got the same procedure.
If your F engine has been line bored, and the caps milled it’s likely that someone has done the work to establish the right clearances and crush so you don’t need (and won’t find) the shims under the main bearing caps.

Since the shims are still present… I’d retain them until a bunch more machine work is accomplished (which … you aren’t doing.)

You’re not turning the crankshaft, so you’re not running oversized bearings, (unless that’s what was present when you dropped the pan!) and nothing has really changed.


P.S. Aftermarket bearing boxes used to come with a paper note inside that told the person performing the assembly what to do with the shims and what clearances to use, but that whole scene probably disappeared 30 years ago.
 
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Yes, things have changed (I was 10 years old in 1972), but the machining on @Cgn1976’s F engine has not.

This is about two things: oil clearance and bearing “crush”. Early engine manufacturing at volume didn’t rely on precision machining. Line boring and line honing were relatively expensive operations in terms of time, so the engines were “fit” by skilled technicians.

Bearing crush wasn’t really accomplishable, so the upper and lower bearing halves were held in-place by dowels. Later the rods and mains got anti-rotate tabs, so the bearings could be changed with the crankshaft still in the block.

The F engine has these tabs.

Anyway, bearing crush and oil clearance are why the Plastigauge procedure is documented.

Before Plastigauge, a small piece of .002" shim stock was placed between the lower main bearing shell and the crankshaft, the cap was torqued, and the flywheel was given a firm tug. If the crankshaft turned freely, a shim was removed. Once the crank turned with a moderate drag, the clearance was assumed to be .002" and the procedure was repeated for the rest of the main bearings. Babbit rods got the same procedure.
If your F engine has been line bored, and the caps milled it’s likely that someone has done the work to establish the right clearances and crush so you don’t need (and won’t find) the shims under the main bearing caps.

Since the shims are still present… I’d retain them until a bunch more machine work is accomplished (which … you aren’t doing.)

You’re not turning the crankshaft, so you’re not running oversized bearings, (unless that’s what was present when you dropped the pan!) and nothing has really changed.


P.S. Aftermarket bearing boxes used to come with a paper note inside that told the person performing the assembly what to do with the shims and what clearances to use, but that whole scene probably disappeared 30 years ago.
Very interesting, thanks for explaining that.
 

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