turned crank

[tractorknut]

I have pulled the engine on a 1955 860 model ford tractor, due to the rear main leaking, and pulled main bearings down while there. I found that it had the rope seal in it, but not the neoprem seal. Anyway, carried the crank which had been turned some time ago 20/20. The machine shop was able to turn it to 30/30, put new bearings in, tightened center main cap to specs and crank locked up. Machine shop said it needed to be line bored. The front and rear bearings didn't show any scars on the bearings, but the center bearing did. Does the line bore sound right to you? Sorry for the long winded post.

Thanks for any input

 

[Bob]

Is the center main cap on backwards, or did someone swap in a cap from another engine?

 

[john in la]

The fact that the old center bearing was scared up while the other 2 were good is proof enough that the black needs to be line bored.

 

[tractorknut]

The cap is on correct, now whether it was swaped out sometime, who knows?

 

[tractorknut]

Thanks for your reply, looks like more money in the money pit.

 

[ErnieD]

I would check the diameter of the crank journal and verify it was turned correctly. Next check to see if the crank is bent. What was the reason for the bearings to be replaced?

 

[GlenIdaho]

Make sure the main bearing caps are in the right order. I had the same problem and found I had mixed them up. Boy, was I embarrassed!

 

[beastlybirdie]

Plasti-gauge, before you do anything. If the clearance is ok, then check the crank for run-out/bent (though the guy doing the grind should have), then look at the journals and line bore as needed.