qtmxmom

So my husband tore my Expedition apart this weekend. One of the bearings was lose, just dropped out when he undid the bolts. The bearing itself was very slightly worn. No scratches, nicks.... just looked slightly worn. The crankshaft looks remarkably okay~ he cleaned the oil ports, bought an oversized bearing (I think 0.25MM) and it seemed really big. He is now contemplating putting the standard bearing back on. Any thoughts on this?

Haynes states that the connecting rod bolts are torque to yield for the main bearing bolts; however, it is not clear if the connecting rod bolts are torque to yield also.

Does anyone know if the connecting rod bolts are reusable or do they have to be replaced? What is the correct torque? torqueSpec online says 31LbFt + 105 degrees......

We called Ford and they sell new connecting Rod Bearing bolts.... since we didn't replace the crankshaft should new bolts be used?

All input is appreciated. Thanks

Bert

They are torque to yield bolts They're supposed to be replaced. The new ones are tightened in two stages, Stage 1: Tighten to 40-45 Nm (30-33 lb-ft). Stage 2: Tighten an additional 90-120 degrees.

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Bert

chipset

If your changing one bearing in a connecting rod your asking for problems. NOT RECOMMENDED. You can't do that. Well you can but you could smash the upper piston
ring and ring land. Bert forgot to tell you.

Bert

Chipset is right. When you put a new bearing in, that raises the upper position of the piston when it goes to the top. If there's any amount of ridge, the rings will hit and break.

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Bert

cannonfodder

I'll have to call bullshit on that one boys.

Bert

You've never seen that happen? If you're in the business awhile, you'll see it happen. Depending on the ring ridge it gas happened.

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Bert

cannonfodder

It must be REALLY EASY to be a master tech if you believe a piston will stop when the crank comes to the end of it's stroke. Do you think there might be a slight possibility that it will continue on until the crank pulls it back down? In which case the new bearing shell and reduced clearances would make this happen quicker not later. Even if you only replaces the upper the piston would turn around at the same time ignoring the fact that the oil pressure may be higher and there is a thicker film on the crank at the end of the stroke so the clearance will be larger if only by an infintesimal amont.

cannonfodder

Try not to run off at the mouth when you really have no grasp of the sitution guys!!!!!

Bert

The bearing wears on the upper shell, as it does, it doesn't push the piston up as high. the ridge forms slowly and if the ridge is large enough, the new bearing puts the upper position higher and the top ring hits it. If it's large enough in both parts, that's what happens. Have you ever tried pushing a piston rod assy out without reaming the ridge? I've seen guys break a piston land too.

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Bert

cannonfodder

Do you have even the faintest idea what inertia is? The piston sure as hell doesn't stop untill the crank drags it back down.