ENGINE
DEFENDER
If the above figures are exceeded the cylinders must
be rebored or sleeved depending upon the
condition of the bores and t he amount of wear.
if the overall wear, taper and ovality
are well within the acceptable limits and the original
pistons are serviceable n ew piston rings may be
Check crankcase main bearings
Discard scored, pitted, cracked and w om bearing
shells. To determine the maximum wear, assemble
the main bearing shells and caps t o the crankcase
and tighten the bolts to the correct torque figure.
fitted. It is important however, that
bores are
deglazed, with a hone, t o give a cross-hatched
finish to provide a seating for the new ring.
Using an inside micrometer, measure each bearing
at several points and note t he greatest figure. The
maximum wear is the difference between this figure
and the smallest diameter of the corresponding
crankshaft journal.
Fitting cylinder sleeves
Cylinder bores that cannot be rebored can be
restored by fitting sleeves to enable standard size
pistons t o be fitted. Sleeving o ne cylinder only will
distort the adjacent bore so sleeving must be
carried out in pairs, i.e. cylinders and 2 or 3 and 4.
The main bearing running clearance is given in the
data section.
1.
Degrease t he crankshaft and clear o ut the oil
ways which can become clogged after long
service.
6.
Machine the cylinder bores t o accept the
sleeves t o 94,425 + 0,012 (3.7175 +
0.0005
in). This will give the sleeve a 0,076 to
0,114
to 0.0045 in) interference fit.
2. Examine visually, the crankpins and main
bearing joumals for obvious wear, scores,
grooves and overheating. A decision at this
stage should be made as t o whether t he
condition of the shaft is worth continuing with
a more detailed examination.
3. With a micrometer, measure and n ote the
ovality and taper of each main bearing journal
and crankpin as follows.
Press the sleeves squarely into the bore using
a pressure of two or three tons. Excessive
pressure could damage the sleeve and cylinder
block.
The sleeves must not be proud of the cylinder
block top face or more than
below the surface.
(0.10 in)
4. Ovality -
each other at various intervals. The maximum
Take two readings at right angles t o
7,
Bore and hone the sleeves t o accomodate the
pistons with the required clearances, see
piston and connecting rod examination.
ovality must not exceed 0,040
in).
Taper - Take two readings parallel to each
other at both ends of the main bearing journal
and crankpin. The maximum permissible taper
Camshaft bearings
Measure the intemal diameter of each
camshaft bearing at several points using an
internal micrometer.
8.
must not exceed 0,025
To check for straightness, support t he front
and rear main bearing joumals in
a dial indicator to check t he
run-out at the centre main bearing journal.
in).
blocks
and
A comparison of the bearing diameters with those
of the respective camshaft joumals will give the
amount of clearance. The bearings should be
renewed if the clearance exceeds 0,0508
in). Or, in any event, if they are scored or pitted.
This work should only b e entrusted t o line boring
specialists.
Run-out must not exceed 0,076
(0.003 in)
taking into account any ovality the centre
journal. The overall wear limit should not
(0.002
exceed 0,114
joumals and 0,088
crankpins.
(0.0045 in) for main bearing
(0.0035 in) for
7.
A crankshaft wom beyond the limints of
It is vital t o thoroughly wash the cylinder block after
machining to remove all traces of abrasive material,
ensuring that all oil galleries are clean.
maximum taper, ovality and overall wear, can
be ground
(0.010 in).
When grinding the crankshaft main bearing and
crankpin joumals, rotation of the grinding wheel and
crankshaft must be in the same direction,
anti-clockwise, viewed from the flywheel e nd of the
crankshaft.
52
| Categories | Land Rover, Land Rover Defender 110, Land Rover Defender 130, Land Rover Defender 90 |
|---|---|
| Tags | Land Rover |
| Model Year | 1990 |
| Download File |
|
| Document Type | Workshop Manual |
| Language | English |
| Product Name | Defender 90, 110, 130 Td5, Tdi, V8 |
| Product Brand | Land Rover |
| Document File Type | |
| Publisher | landrover.com |
| Wikipedia's Page | http://en.wikipedia.org/wiki/Land_Rover |
| Copyright | Attribution Non-commercial |
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