Crank shaft bearings

[George Miller]

Originally Posted by Rich Bowes

How often should crankshaft bearings be checked. I have heard every 5000 miles. Is that correct?

When it is needed. There really is no answer to this question. Depends on how good the Babbitt was done how good the bearings were set. How fast you drive, plus a lot more.

I would just pay attention to the sounds of the engine when it is under load. If it knocks under load you may have a loose main. Also when you first start it after it has been setting for a while. The center main will knock when you first start it, on tell it gets oil if it is loose.

If you have to take the pan off for some reason, or you have a bad rear main leak check them then.

[Rich Bowes]

As some of you have suggested, the correct answer is: "if it ain't broke, don't fix it", or "don't go looking for trouble unless it comes knocking". Do I have this about right?

[Patrick L.]

Originally Posted by Rich Bowes

As some of you have suggested, the correct answer is: "if it ain't broke, don't fix it", or "don't go looking for trouble unless it comes knocking". Do I have this about right?

It may be smooth and quiet with no load and not rear its ugly head until put under a load. Then it can be hard to hear but may be felt. Main bearing that is.
If it seems OK, it probably is. If for reason the pan ever comes off, then is a good time to check them.