Inspection - Ford Ranger Maintaince And Repair Manual

INSPECTION

Now that the engine block and all of its components are clean, it's time to inspect them for wear and/or
damage. To accurately inspect them, you will need some specialized tools:
• Two or three separate micrometers to measure the pistons and crankshaft journals
• A dial indicator
Telescoping gauges for the cylinder bores
•
A rod alignment fixture to check for bent connecting rods
•
If you do not have access to the proper tools, you may want to bring the components to a shop that does.
Generally, you shouldn't expect cracks in the engine block or its components unless it was known to leak,
consume or mix engine fluids, it was severely overheated, or there was evidence of bad bearings and/or
crankshaft damage. A visual inspection should be performed on all of the components, but just because you
don't see a crack does not mean it is not there. Some more reliable methods for inspecting for cracks include
Magnaflux®, a magnetic process or Zyglo®, a dye penetrant. Magnaflux® is used only on ferrous metal (cast
iron). Zyglo® uses a spray on fluorescent mixture along with a black light to reveal the cracks. It is strongly
recommended to have your engine block checked professionally for cracks, especially if the engine was
known to have overheated and/or leaked or consumed coolant. Contact a local shop for availability and
pricing of these services.
Engine Block
ENGINE BLOCK BEARING ALIGNMENT
Remove the main bearing caps and, if still installed, the main bearing inserts. Inspect all of the main bearing
saddles and caps for damage, burrs or high spots. If damage is found, and it is caused from a spun main
bearing, the block will need to be align−bored or, if severe enough, replacement. Any burrs or high spots
should be carefully removed with a metal file.
Place a straightedge on the bearing saddles, in the engine block, along the centerline of the crankshaft. If any
clearance exists between the straightedge and the saddles, the block must be align−bored.
Align−boring consists of machining the main bearing saddles and caps by means of a flycutter that runs
through the bearing saddles.
DECK FLATNESS
The top of the engine block where the cylinder head mounts is called the deck. Insure that the deck surface is
clean of dirt, carbon deposits and old gasket material. Place a straightedge across the surface of the deck along
its centerline and, using feeler gauges, check the clearance along several points. Repeat the checking
procedure with the straightedge placed along both diagonals of the deck surface. If the reading exceeds 0.003
in. (0.076mm) within a 6.0 in. (15.2cm) span, or 0.006 in. (0.152mm) over the total length of the deck, it must
be machined.
CYLINDER BORES
The cylinder bores house the pistons and are slightly larger than the pistons themselves. A common
piston−to−bore clearance is 0.0015−0.0025 in. (0.0381mm−0.0635mm). Inspect and measure the cylinder
bores. The bore should be checked for out−of−roundness, taper and size. The results of this inspection will
determine whether the cylinder can be used in its existing size and condition, or a rebore to the next oversize
is required (or in the case of removable sleeves, have replacements installed).
INSPECTION
HOW TO USE THIS BOOK
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