Kerr Pump Corporation KT-3350XP, Parts And Service Manual

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G. DISASSEMBLY OF POWER END
CAUTION
: Prior to disassembly of any power end, the plunger, pony rod, and pony rod seal housing must be removed.
Expose the crankshaft and connecting rods by removing the pan cover. Connecting rod caps may now be removed and the connecting rod
and crosshead should be shoved all the way to the rear (toward the fluid end) to facilitate crankshaft removal out either side as convenient.
The connecting rods and crossheads may now be taken out the front cavity exposed by removing the crankshaft. Connecting rods may be
removed from the crosshead by loosening the setscrew and driving out the wrist pin from the crosshead. A bronze bushing is used in the rod
it may be driven out of the rod and replaced with a new bushing. Reassembly is the reverse of the above outlined sequence with the
following considerations for “fits” or tolerance:
i. General: All Kerr components are machined on modern production machine tools and are of the same specifications and close
tolerances you would expect in a modern automobile engine. It must be pointed out that at top speed (350 to 400 RPM) your pump
will not even be approaching idle speed for a gasoline engine so “field fits” are possible and practical when making repairs and
replacements away from the factory. All procedures outlined below are possible with only hand tools and absolutely no instruments,
special tools, or gauges are needed.
ii. Connecting rod and wrist pin: Proper fit will find the wrist pin turning freely in its bore in the connecting rod, but it should have no
“wobble” that is discernable up and down the main axis of the connecting rod. This looseness in the wrist pin fit is the most probable
cause of “knocking” which is traceable to the power end of most all pumps. The only solution for loose fitting wrist pins is to discard
the connecting rod wrist pin bushing and replace with a new one. If any wear is visible on the wrist pin it should always be replaced.
iii. Crankshaft End Play and Lateral adjustments: Adjustment of the Taper Roller bearings used in all Kerr Pumps is accomplished by
removing or adding shims under the bearing housing. Shims are taken out or added until the crankshaft (without connecting rods)
will turn freely, but with no endplay felt when attempting to pull or push the jackshaft end of the crankshaft along its long axis. Some
lateral adjustment is possible by removing shims from one side of the crankshaft and adding them to the opposite side. (Note:
Lateral adjustment is the “centering” of the crankshaft in the power frame housing.)
iv. Connecting Rod to Crankshaft fitting: Factory bored connecting rods will normally fit the standard crankshaft journal just by bolting
the cap on the rod with the standard rod shims being used. If the caps do require adjustment this is accomplished by removing or
adding various thicknesses of rod shims. The standard connecting rod shim used on all Kerr Pumps is 1/32” thick and is comprised of
.002” laminates, which can be “pealed “ off separately. Proper fit of the connecting rod will allow the pump crankshaft to be rotated
while not allowing in ‐ and ‐ out slack in the connecting rod along its long or main axis. A well ‐ fitted rod will have none of the in ‐ and ‐ out
slack, but should be free enough to be moved from side to side on the rod journal. This insures the rod not being too tight. A point of