the wifes 66 Mustang 289 distroyed the thrust bearing surface on the crank, I don't know who built this engine or how many miles on it, but when I pulled the main cap and bearing there was no great wear on the bearing thrust surface, it measured at -.001, any ideas???? I'm at a loss for this

 

Was the crank welded up?

 

I don't think the crank was welded, I don't know which PO had the engine work done, but the crank is still std. so it hasn't been turned, I'm sure it was probaly some cheap rebuilt short block.we have had it since 2000 and put about 50,000 on it and don't know what the previuos milage was on the engine, everything else is tight, no smoke or oil usage and the bearing surfaces look good

 

Since there's minimal wear on the bearing itself, and the damage is done just to the crank, I would say the damage was done before the rebuild, and they didn't bother fixing it- you say the crank hasn't been turned- so they just threw a new set of bearings in it and called it good.



Pete

 

And they got away with it!

 

When a crank is welded up due to damage they return it to standard size or the size of the rest of the journals. I have seen cranks with a bad weld job show up as an irregular surface in the radii or thrust surfaces.

 

Thanks for the opions guys, I guess anything is possible...I just couldn't believe the amount of wear on the crank but not on the bearing face, it was moving so far forward the flywheel (flexplate) was engaging the starter drive, I originaly thought I had a starter problem, thats when I dicovered the real problem

 

I was curious what prompted you to check- wow, that's bad.


Pete

 

and naturaly this didn't happen at home, but about 15 miles away in a parking lot, so I put 2 washers between the starter and bellhousing and was able to start it and drive it home..if the problem with the starter hadn't happened I wouldn't have known...and then when I pulled the pan to check the bearing, which I asumed was the problem, but not with my luck..LOL..the lucky part was how close the crank throws were to the piston skirts...a few more thousands and it would have hit them...

 

and naturaly this didn't happen at home, but about 15 miles away in a parking lot, so I put 2 washers between the starter and bellhousing and was able to start it and drive it home..if the problem with the starter hadn't happened I wouldn't have known...and then when I pulled the pan to check the bearing, which I asumed was the problem, but not with my luck..LOL..the lucky part was how close the crank counterweights were to the piston skirts...a few more thousands and it would have hit them...

 

You stated the "flexplate" so I assume that it is an automatic.
So many people think that manual trans vehicle wear out the thrust worse.
But it seems that the auto trans are the worse. You usually need constant pressure pushing the crankshaft forward. They state that if the fluid pressure in a trans. get high it can ballon the converter & apply pressure all the time, causing a thrust failure.

From what I have seen, a softer material will usually wear better than a harder. Seems like the soft material will embed the hard particles, then the harder part like the crankshaft, is then rubbing against ends up wearing. Over head cam engines with no bearings, just the material of the head (aluminum) in a dirty situation the camshaft always wear out and the bearing area is fine.

Just an idea

 

Thanks Tim, thats great info I wasn't aware of, this is the only car with an Auto trans I have ever owned, I personaly hate them, and don't know much about them..I'm old school and have driven sticks all my life and been building Fords since 1964 and have never had this happen on any stick cars/trucks...something I will check out for sure