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

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

If your rod bearings are ok, Im going with a spun main bearing. Pull your main caps off, you will find your problem!
 
The manual shows how to use the main cap bolts to apply a little leverage to crack the caps loose.

Maybe loosen them one at a time (back the bolt heads on each cap out 1/4”) and try to turn the crankshaft after each is loosened. If there is Babbitt transfer to the main journal(s), this should allow it to pass.
Tried that. No go. Can't get the front cap to budge or the crank to drop at all. Have the front main cap bolts out and the rest loose a bit. Nothing changed thus far, but i don't think the crank has moved down at all.

Your next post about dropping the trans...Not something I can do now. I don't have much more time till the weekend and then not probably going to happen. Not to mention I've never done that before. Gotta read about what I'd need to even do it. I'm sure I don't have everything I need. Just read the process for pulling the engine....Might be coming to the end of my abilities, time and effort thresholds here. Was hoping for the bandaid level fix or something without tearing quite so deep. Doesn't appear to be in the cards. I think I'll try a little more to get the main front cap off without damaging anything and then maybe this weekend pull the radiator, timing cover and see what's in there....but

a rebuilt 2F is starting to sound nicer by the damn second, even as expensive as that's gonna be. Already losing confidence that I'm gonna be able to get apart what I need apart and then back together and functioning properly again? I could just see myself thinking I have it after tons of work to then screw something else up and have to go back to start. Not worth the aggravation & time suck and this may be the only time I'm gonna have the opportunity $$$ wise to pull this trigger any time soon.
 
Can't get em off!
Put your prybar back on the flywheel, turn your 2 teeth one way, then 1 tooth back. Maybe un -bind it?
Maybe pull the timing cover and check for physical obstruction before you give your flywheel hell.
 
Actually, maybe, If you have the means, drop the transmission before you go much further.
Dropping the trans is a big, hard job. Re-installing a trans is a bigger, harder job.
Let us exhaust all other possibe remedies before we resort to that
 
Not sure what dropping the trans would achieve? If a main bearing has spun, it will bind the whole crankshaft including the main caps.
 
Ok, thinking more. Your crankshaft is not going to drop even if all maincaps are removed. Transmission input shaft won't let it.
 
Ok, thinking more. Your crankshaft is not going to drop even if all maincaps are removed. Transmission input shaft won't let it.
Makes sense. That said, I still can't get the front cap to budge. Was gonna use the mallet, but didn't want to damage the area where the oil pan gasket sits, therefore creating a leakage point later. I'll see if some force on the sides of it will break it free.
 
Find the easiest main cap to get to, get medieval on it. Get it off.
Time to show that engine who's boss...
 
If you run out of cuss words I have a few in reserve, just trying to help! :)
I work in sustainable building so I tend to just recycle the good old MFr!

Mother Fr!!!!!!!!!!!!!!!!!!!!!!!!

It does look like my land deal is a go so, making a fresh motor happen is 100% in the cards. Gonna go little deeper down the rabbit hole first though...Maybe there's a chance! Either way i think the AC is getting bumped for a while :rofl:
 
It does look like my land deal is a go so, making a fresh motor happen is 100% in the cards
Then tie that winch cable to a tree jam that thing in high gear and literally break it free.
Take lots of pictures..

cffmbl-jpeg.457946
 
Last edited:
Tried that. No go. Can't get the front cap to budge or the crank to drop at all. Have the front main cap bolts out and the rest loose a bit. Nothing changed thus far, but i don't think the crank has moved down at all.

Your next post about dropping the trans...Not something I can do now. I don't have much more time till the weekend and then not probably going to happen. Not to mention I've never done that before. Gotta read about what I'd need to even do it. I'm sure I don't have everything I need. Just read the process for pulling the engine....Might be coming to the end of my abilities, time and effort thresholds here. Was hoping for the bandaid level fix or something without tearing quite so deep. Doesn't appear to be in the cards. I think I'll try a little more to get the main front cap off without damaging anything and then maybe this weekend pull the radiator, timing cover and see what's in there....but

a rebuilt 2F is starting to sound nicer by the damn second, even as expensive as that's gonna be. Already losing confidence that I'm gonna be able to get apart what I need apart and then back together and functioning properly again? I could just see myself thinking I have it after tons of work to then screw something else up and have to go back to start. Not worth the aggravation & time suck and this may be the only time I'm gonna have the opportunity $$$ wise to pull this trigger any time soon.
However limited you think your skills are, make no mistake that they are growing by leaps and bounds as you go through these steps to diagnose!

A 2F might be the ticket, but see this through and figure out your issue -

go-for-it-you-can-do-it.gif
 
Agree it’s unlikely to be in a cylinder/combustion chamber. Only thing I can think of there is a broken piston ring that’s limiting one of the remaining two pistons, since the rod journal would move away from the rod in one of the two directions. Pulling the head is unlikely to show a broken ring; but maybe it scored the cylinder before things locked up.

According to cnzjzy.com, the F/2F flywheel ring gear is 349.7mm OD 319.3mm ID and has 136 teeth. This means the circumference of the ring gear is 1098.61mm, so each tooth is about 8.08mm or 0.318”, which is just over 5/16” for those of us who are old.

More importantly, if the flywheel is moving 2 teeth, that’s 2/136 * 360 degrees. About 5.3 degrees. At/around TDC (and BDC) the piston doesn’t change position much as the crank rotates. I don’t know the center to center length of the rods, or I’d calculate it.

Since #3 and #4 are near TDC the pistons aren’t moving very far with 5.3 deg of crank rotation.

I can’t think of how a follower (“lifter”) would break to bind in both directions. Same thing with the crank/cam gears.

One thing to note: the F engine oil system allows oil from the pan into the engine. There is a tee where the oil flows both to the filter housing and the oil galley that feeds the main journals. If something broke and passed to a point far enough to block the galley on one journal, you might still see oil everywhere on the rods, if you got lucky.



My guess is still a main bearing.

View attachment 2810240

View attachment 2810241
Hmm... I wonder what % of oil gets filtered in this scenario?

Maybe they figured over time, all the oil would get filtered...
 

Users who are viewing this thread

Back
Top Bottom