![background image](http://html1.mh-extra.com/html/jabiru/2200/2200_overhaul-manual_3122313083.webp)
Engine Overhaul Manual
Jabiru Aircraft
Pty Ltd
Jabiru 2200 & 3300 Aircraft Engines
This document is controlled while it remains on the Jabiru server. Once this no longer applies the document becomes uncontrolled.
ISSUE
1
2
3
4
5
6 7
Dated : 28/10/2014
Issued By: AS
Page: 83 of 201
L:\files\Manuals_For_Products\Engine_Manuals\Overhaul_Manual\JEM0001-7_Overhaul_Manual_DRAFT_(29_10_14).docx
5.11.8 Rockers
5.11.8.1 Mandatory updates
Engines being converted to pushrod oil feed must use new lifters, pushrods, rockers and rocker bushes
as detailed below.
5.11.8.2 Inspection and repair
Figure 97
– Fitting Rocker Bush
Measure the rocker shafts and the rocker bushes and calculate the clearance
– ensure it is within the
limits given in Table 10. Bushes are replaced during a full overhaul. If the clearance is greater that this
limit then new rocker bushes must be ordered.
Use a hand press to push the old bushes out with the new bushes, making sure that the split joint in
each bush is oriented towards the top of the rocker as shown in Figure 97 (left). Typically the inner size
of fresh bushes is around 12.06mm.
Note that for engines using the hollow pushrod oil feed there must be an oil hole in the rocker bush as
shown in Figure 97 (right). If this hole is not present rapid wear of the bush will occur.
Push the new bushes completely into each rocker
– the width of the bush determines the amount of end
float for the rocker.
Rocker shafts must be inspected for serviceability. Check for scoring etc
– slight imperfections can be
polished out
– larger damage requires the replacement of the shaft. Shafts measure 11.98mm when
new. If using a shaft with slight wear it can be inserted into the head from the other direction which
places the worn section on top of the shaft where it will not wear anymore or affect rocker operation.
In all engines the rocker end which presses against the valve stem must be checked for wear. In some
cases this face may require polishing to remove defects.
For engines using the hollow pushrod lubrication system the valve rockers are equipped with an oilway
running from the pushrod socket to the tip of the rocker (see Figure 98). This oilway also feeds into a
groove in the bush installation bore. At overhaul or when new parts are fitted these oilways must be
inspected visually and using a fine probe (such as a 1.0mm drill bit) to ensure they are open and free of
obstructions. After probing blow the oilways out with compressed air to shift any debris.
In solid valve lifter engines the rocker adjusters & lock nuts must also be examined & assessed for wear
Rocker arm
Bush
Split joint
Oil hole in bush