Machine Shop ruined stat gear bearings

[RETed]

Originally Posted by JustJeff

^ thanks, I called the owner as soon as I got home and looked them over in better lighting. He claims that there is no way their press could have damaged the bearings because they used aluminum...which couldn't have damaged the bearing...???

Is this a reputable shop???

This guy is an idiot.
(Journal) bearing material is usually some soft metal like lead, antimony, etc.
http://en.wikipedia.org/wiki/Babbitt_(metal)
Although aluminum's harness is very close to (pure) lead and (pure) antimony, enough abuse will cause damage.
On top of that, you can work harden aluminum to the point where it can get harder than the bearing babbitt surface - any competent person who does metal machining should KNOW this.
http://www.tedpella.com/company_html/hardness.htm
Damage to a journal bearing surface is DEATH.
I bet the aluminum guide / bearing press had sharp edges or the person doing the work was hamfisted or drunk.


-Ted