How Often Should Bearing Clearance Be Checked?

Utopia Texas

Utopia Texas

Senior Member
If a Model A engine is maintained on a regular basis, changing the oil every 500 miles, what is the normal mileage at which one should check the engine bearing clearances
 
You are changing the oil too often. The 500 miles is for poor quality oil from the 1930's. Todays oils (assuming you are using detergent oil with additives) can go a couple of thousand or two no problem unless you are running dirt roads and such.

Babbitt gets checked when it make noise. Original babbitt would have been done a few times in the 50,000 to 80,000 miles you got out of it. If you have lead babbitt then all bets are off.
 
Kevin, Is there a babbitt that has no lead in it. I thought bearing babbitt for the Model A was a combination of lead, tin and antimony?
I realize a 500 mile oil change with modern oils may be a bit of over kill but since these motors sit most of the time with my high humidity in S.E Texas it could not hurt. I maintain and service 6 tractors and 37 other pieces of machinery here on our farm and have done so for over 45 years and like to keep things like bearings on these older cars adjusted before they make noise or pound themselves out.
I am just curious if those that put many miles on their Model A motors have found a ball park number of miles where bearings need to be checked.
 
Keep changing the oil as you have been. I do it with less miles than that..
Oil is cheaper than engines, especially if it is unfiltered
This comes up all the time and it's usually a matter of frugality
 
It depends on the quality of the babbitt job, a poor quality job can be loose and falling apart in less than 3000 miles----and original engines that still have original shims at over 60,000

If the babbitt in the block and cast rear cap wasn't peined properly the clearances can open up quick

if there is a problem with flywheel balance or crankshaft centerline causing imbalance the forces will work at increasing clearance more rapidly

if the line bore came out slightly too large and it was tightened up by removing shims the clearance will increase faster because on the size mismatch (only tight top--bottom--not full circle fit)

So I will give a range of under 5000 to over 40,000----
 
I knew a Guy that rigged an oil pump to an electric motor & pumped ALL his waste oil from his cars & trucks through an Old Franz, toilet paper filter & re-used it!
Bill W.
 
The problem with just physically filtering oil is that over time the chemical additive package is used up which is why modern oils are superior to older single grade oils. You dump the filtered oil back into a engine and all the anti wear, anti foaming and anti shearing qualities are gone. Save a penny to spend a dollar. :)
 
Kevin in NJ said:
You are changing the oil too often. The 500 miles is for poor quality oil from the 1930's. Todays oils (assuming you are using detergent oil with additives) can go a couple of thousand or two no problem unless you are running dirt roads and such.

Babbitt gets checked when it make noise. Original babbitt would have been done a few times in the 50,000 to 80,000 miles you got out of it. If you have lead babbitt then all bets are off.
Click to expand...

Careful now, some of us don't hear very well. The trouble with waiting to check your Babbitt until you hear noise is that often, it is too late as, damage has already occurred.

For a car you do not know the history of maintenance, I think it is wise to check your clearances in the next non-driving season, record your clearances before adjusting, adjust the clearances and record clearances again. Keep the clearance info safely tucked away in the car along with the odometer reading and adjustment date.
Drive 3000 to 5000 miles and complete the same check. If the bearings need adjusting but have not been making noise, you have determined the required clearance check interval. If there is no change in the clearances, you know you can drive a much greater interval between checks.

The required interval is different for every type of car and driver. The harder a car gets driven, the more often it will require adjustment.

I see lots of engines come into my shop for bearing adjustment because of a noise and it is already too late. Lots of money is spent for lack of a timely check on bearing clearances. JMO
Good Day!
 
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I thought dad told me about every 10k for a earring check. That is assuming the pour was good. The rate I drive it will be every 5 yrs. that I need to check the bearings.

Mike
 
It depends on many things. How good the job was, how fast it is driven, how many hills, how cold or hot the weather was. How you use the spark, Even what kind of oil you use. Not sure if white walls make any difference.

Had a town sedan one time with 85.000 miles on it. When I ground the valves and adjusted the bearings it still had all the shims. It look like the engine had never been apart. This car I'm sure lived in a city all its life. No mud or dirt under the fenders, no rust. It came from Virginia.
 
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