1919 Cadillac - GM Heritage Center

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PART II
ADJUSTMENTS
ENGINE
ADJUSTMENT OF CONNECTING ROD AND CRANKSHAFT BEARINGS
Adjustment
of Connecting Rod Bearings
Remove the oil pan and baffle plate. (See "Removal" under "Oil
Pan and Baffle Plate," page 102).
The caps at the lower ends of the single connecting rods are adjustable.
Liners varying in thickness from .002 inch to .006 inch are placed
between the caps and the rods when the engine is assembled. To
readjust, remove these liners and substitute thinner ones of the proper
thickness.
These bearings should have from .0025 inch to .0035 inch play.
Bearing trouble is probable if the clearance is less than .0025 inch.
The crank pin bearings in the forked connecting rods are not
adjustable. If there is more than .006 inch clearance between a
bearing and the crank pin, or more than .015 inch end play in the
bearing, a new bearing should be substituted. (See under "Fitting
Crank Pin Bearings," page 29).
Adjustment of Main Crankshaft Bearings
Remove the oil pan and the baffle plate. (See "Removal" under
"Oil Pan and Baffle Plate," page 102).
The three main bearings are provided with liners which are clamped
between the crankcase and the bearing caps.
To tighten a main bearing, proceed as follows: Remove the oil
feed pipe connecting the bearing cap with the oil manifold. Remove
the aluminum bearing cap with the lower half of the bearing and the
liners.
Replace the liners with liners which are less in thickness by an
amount equal to the amount of "take-up" necessary. The clearance
between the shaft and the bearings should be between .001 inch and
.002 inch. Liners can be obtained from the Cadillac Motor Car
Company varying in thickness by .001 inch.
Carefully reduce the upper edges of the lower half of the bearing
just enough to allow the aluminum bearing cap to clamp the new liners.
This work must be done very accurately, as clearance between the
halves of the bearing will cause an oil leak.
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ADJUSTMENTS 29
The upper edges of the lower half of the bearing may be reduced
by rubbing the bearing on a piece of fine emery cloth stretched tightly
over a flat, machined, iron surface.
Thoroughly clean the bearing, bearing cap and liners and oil the
bearing surface before replacing.
In replacing the bearing cap, tighten the bearing nuts firmly and
lock with new cotter pins. Also make sure that the union nuts on the
oil pipe are tightened sufficiently to prevent leakage.
If more than one bearing is removed at a time, care should be taken
not to mix the liners, as they may not all be the same thickness.
After replacing the oil pan, refill it with 1½ gallons of suitable
engine oil. Cadillac Motor Oil is recommended.
FITTING CRANK PIN BEARINGS
If the crank pins of the crankshaft are scored or out of round more
than .003 inch they should be dressed down before used bearings are
refitted, or new bushings are installed. (See under "Dressing Down
Crankshaft Bearing Surfaces," page 30).
Refitting a Used Bearing
If the babbitt is scored, rough, or shows only partial bearing on
the crank pin, clean it up with a scraper. This work should be
attempted only by workmen familiar with bearing scraping. The
work must be done carefully to prevent an excessive flow of oil by the
bearing.
If, after completing the work, the clearance between the bearing
and the crank pin exceeds .006 inch, a new bearing should be substituted.
The end play in a crank pin bearing should not exceed .015 inch.
Fitting a New Standard Size Bearing
Crank pin bearings of standard size are reamed before shipment
and should not be scraped unless the bearing surface becomes injured.
If there is more than .006 inch clearance between a new standard
size bearing and the crank pin, an undersize bearing should be fitted.
Unreamed bearings .005 inch undersize are furnished by the Cadillac
Motor Car Company.
The end play in a crank pin bearing should not exceed .015 inch.
Fitting a New Undersized Bearing
Unreamed crank pin bearings .005 inch undersize are furnished by
the Cadillac Motor Car Company for use where the clearance between a
crank pin and a new standard size bearing exceeds .006 inch.