Does touching bearing surfaces ruin them?

High entensity electric lamps and strobe flash tubes can be ruined from the acids & oils in fingerprints due to the high temperatures they operate at. I always handle those with a tissue during replacements. Some are even too expensive to take that chance. The highest dollar ones I've worked with are for the aircraft search lamps with 8,000,000 or more candlepower. Some are over $1,800.00 each. With a price like that you take all the care you can with them and wear surgical gloves.
 
The deal about not criss-crossing radial tires is very out-dated. This was a problem with the first radials such as Firestone 500's and 721's but this was corrected long ago (25 or more years ago). Check your car's owner's manual for tire rotation instructions. You will see that they recommend some type of side-to-side switch.
Still too many myths, legends and old wives' tales in this business, but I guess if it makes a person more meticulous in his work habits, that's good!
P.S. My favorite myth is the one that says if you line up the ring gaps on a piston, the engine won't have enough compression to start!! Poppycock!
 
My early career was with Federal Mogul Corp. Some of you may know of them. There has been all kinds of advise here. As an engine bearing salesman and having gone through many hours of factory training I will tell you this. Engine bearing 101, Never touch the bearing surface with your fingers. The acid from your body will actually etch your finger print into the bearing surface. Call it hog wash but I have witnessed it first hand on several occasions. Our competitors will tell you the same thing be it TRW, Clevite, Michigan etc. My customers included several engine rebuilders and speed shops, ie; Jack Merkel on L.Is. Jasper etc. I have never seen them touch the bearing surfaces with their bare hands. You will get all kinds of information from all kinds of people. When I worked for F. M. we had a tech department that anyone was able to call with questions. Do you want an answer from an expert? Call them, hopefully the tech department is still there. The Corporate headquarters is in Southfield Mich.
I was retired in 1989.

Rich O.
 
Rich Overton said:
My early career was with Federal Mogul Corp. Some of you may know of them. There has been all kinds of advise here. As an engine bearing salesman and having gone through many hours of factory training I will tell you this. Engine bearing 101, Never touch the bearing surface with your fingers. The acid from your body will actually etch your finger print into the bearing surface. Call it hog wash but I have witnessed it first hand on several occasions. Our competitors will tell you the same thing be it TRW, Clevite, Michigan etc. My customers included several engine rebuilders and speed shops, ie; Jack Merkel on L.Is. Jasper etc. I have never seen them touch the bearing surfaces with their bare hands. You will get all kinds of information from all kinds of people. When I worked for F. M. we had a tech department that anyone was able to call with questions. Do you want an answer from an expert? Call them, hopefully the tech department is still there. The Corporate headquarters is in Southfield Mich.
I was retired in 1989.

THANK YOU!
Click to expand...
 
I know a guy that put a Y Block together in the kitchen of his house, that was the only clean place to work. I can't image what my wife would say if I brought a Flathead into my house, and washed parts in the dishwasher!
 
Rich Overton said:
My early career was with Federal Mogul Corp. Some of you may know of them. There has been all kinds of advise here. As an engine bearing salesman and having gone through many hours of factory training I will tell you this. Engine bearing 101, Never touch the bearing surface with your fingers. The acid from your body will actually etch your finger print into the bearing surface. Call it hog wash but I have witnessed it first hand on several occasions. Our competitors will tell you the same thing be it TRW, Clevite, Michigan etc. My customers included several engine rebuilders and speed shops, ie; Jack Merkel on L.Is. Jasper etc. I have never seen them touch the bearing surfaces with their bare hands. You will get all kinds of information from all kinds of people. When I worked for F. M. we had a tech department that anyone was able to call with questions. Do you want an answer from an expert? Call them, hopefully the tech department is still there. The Corporate headquarters is in Southfield Mich.
I was retired in 1989.

Rich O.
Click to expand...

I have no argument with the concept, that acids from human hands can microscopically etch metal surfaces. But, will the consequences produce harm or impact the function or life of the bearing? NO JMHO
 
Reminds me of one of the many "trouble jobs" I visited. I visited a "mechanic' in a service station in 1961 that had a two bay garage. On the lift was a 1949 Chevy that the "greasy old timer" had rebuilt the engine and the bearings failed. The pan was on the dirty floor. After many questions on my part I asked how he measured the crank to come up with .010 under bearings. "Just like this," as he reached up and between his thumb and fore finger rubbed the journal exclaming I've been doing this for over 20 years and I can tell that the journals are about .010 under. this is the first failure I've ever had." Your bearings are no good!" With that I suggested that he purchase my competitors bearings from now on. I then issued a credit for the bearings to the jobber that sold them to him with instructions to not sell him anymore F.M. bearings.

No offense but....microscopic etching ????? There is an awful lot of good advise on this site. But, you have gone through the trouble of tearing down an expensive piece of machinery, cleaned it, machined it etc. etc.dreaming of perfection. Your surely familar with Murphy's Law. Why chance it???! Do as the manufacturer of the part instructs you. ie; and when all else fails, read the manual.

Respectfully,

RichO.

Rich O.
 
I respect your opinion, as you do mine, but lets get back to the original question. No, his bearing is not ruined.
 
As I put my motor together, I told the machinist who did the work that I had only helped put a motor together once before, so I really didn't know what I was doing. He seemed confident that I could put it back together myself.
I asked a bunch of questions, and he never mentioned anything about not touching the bearings with my bare hands. I used a few different bearing manufacturers, and there are no warnings on or in the boxes. The flathead books I've been reading don't seem to mention anything there either. I'm not saying that finger oils don't do damage to metal- any guitar player can tell you what it does to strings over time. I would think if it was really that crucial not to touch the bearings that the bearing boxes would have warnings on them, like how halogen lights have often.
I found this article and basically did as this guy said to start. After a little bit I just put gloves on. I would also clean the bearings a couple times with paint thinner just to make sure before putting any lube on. I believe I installed all the rod bearings with gloves on.
http://www.mgaguru.com/mgtech/engine/cs205e.htm
I'd say to clean that bearing with mineral spirits or rubbing alcohol, maybe put a thin coat of lube on it if it will sit. It should be fine.
 
Most folks by human nature, can only give information by memory and what they consider to be unnecessary OR common sensical information sometimes gets left out.

After washing parts up to get ready for reassembly, my hands are solvent clean but I still wash them in soap and water before I get started on a basic assembly procedure. During assembly my hands get pretty oily with make up oil or assembly lube if you prefer plus antisieze or whatever else is required for assembly. I put antisieze on the back of the shells to prevent them from fretting on aluminum case engines and it works. This process required the bearing to be handled whether you use gloves or not. There isn't enough natural fingerprint oil on my hands to make any difference one way or the other after I get lube all over them. Now maybe I should use surgical gloves during assembly to protect my skin but I don't. That's just the way I've done it and I'm too old to change my ways now. I wash my hands multiple times as the build up of oil gets to be in the way of proper assembly.

If a person touches a bearing's tin or whatever coated surface when they are inspecting a bearing shell right out of the box then it will tarnish the coating so it's not a good idea to do that until your ready to do the assembly, especially if your going to put it right back in the box. I wonder how many counter men at the parts store handled the bearing before I ever got it in the first place? You just never know and life is too short to sweat the little things.

Mechanics are the ones that have to wash their hands both before and after they go to the bathroom
 
Last edited:
Ol' Ron said:
I do hank my cranks from a rack to hold them vertical and safe. I also use a fine scuff pad on all my bearings, gives the surface a texture to hold oil during initial run in, then wash is soapy water.. Not sure if it works, but can't hurt. Been doing it for 60 years. Doesn't mean I'm right, just old.
Click to expand...

I was about to say what happened to washing with soapy water ?
 
You must log in or register to reply here.
Back
Top