3/1/2003
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What’s up with revised rocker arms for the Mazda 3.0L MPV and 929 SOHC engines?
A. The AERA Technical Committee offers the following information regarding revised rocker arms and shafts for 1989-’96 Mazda 3.0L SOHC engines. To reduce customer complaints of upper engine noises, consider this information any time rocker arm service is performed.
To reduce the likelihood of hydraulic lash adjuster (HLA) noise, the depth of the HLA locating hole has been reduced.
To help distinguish this revised rocker arm it is identified by a "projection" on the camshaft end of the rocker as shown in Figure 2. The original rockers shown in Figure 1 do not have a projection in that location.
To reuse original style rockers for those engines that have exhibited noise complaints a "washer" is available to insert under the HLA as shown in Figure 1. The "washers" are available as p/n JEY1-12-SHO and are packaged 18 per part number.
Rocker arm shafts and rockers for intake and exhaust sides are unique to their location. The revised style rockers and shafts can be used in place of the original style components, but not vice versa
Q. Our shop trainer needs info on installing Chrysler 5.9L cylinder sleeves.
A. It can always be helpful to review the basics. Chrysler advises that 1998-2001 5.9L VIN 6 and 7 turbo 24-valve engines can be repaired by installation of cylinder sleeves if the following procedure is employed.
IMPORTANT: If more than .03937˝ (1.000 mm) diameter oversize bore is required, the block must be bored and a repair sleeve installed.
The following procedures will ensure a quality repair:
1) Bore the block cylinder bore to 4.1142˝-4.1148˝ (104.500-104.515 mm) and leave a .250˝ (6.35 mm) step on the bottom of the bore.
2) Repair sleeves can be replaced by using a boring bar to carefully bore out the old sleeve. DO NOT cut the cylinder bore beyond the oversize diameter limit.
3) After machining the block for the new repair sleeve, thoroughly clean the bore of all metal chips debris and oil residue before installing the sleeve.
Sleeve Installation Prep:
1) Cool the repair sleeve(s) to a temperature of 10° F (-12° C) or below for a minimum of one hour.
2) Wear protective gloves to push the cold sleeve into the bore as far as possible.
3) Be ready to install the sleeve immediately after removing it from the freezer.
4) Apply a coat of anaerobic retaining compound such as Loctite 620 or equivalent to the bore that is to be sleeved.
5) Using a sleeve driver, drive the sleeve downward until it contacts the step at the bottom of the bore.
Bore Preparation:
1) Set up a boring bar and machine the installed cylinder sleeve to a diameter of 4.014˝ (101.956 mm).
2) After removing the boring bar, use a honing stone to chamfer the top corner of the sleeve repair to provide a 15° angle chamfer .049˝ (1.25 mm) wide as shown in Figure 3.
3) Cylinder bore honing should be done on approved equipment to produce a correctly honed surface with a crosshatched appearance with the lines at 15° to 25° angles with the top of the cylinder block. For the rough hone, use 80 grit-honing stones.
4) To finish hone, use 280 grit-honing stones. Finished bore inside dimension is 4.0165˝ +/- .0008˝ (102.020 mm +/- 0.020 mm). A maximum of 1.2 micrometer (48 micro-inch) surface finish must be obtained.
After finish honing is completed, immediately clean the cylinder bores with a strong solution of laundry detergent and hot water. Wipe the bore with white lint-free, lightly oiled cloths. Make sure there is no grit residue present. Apply a rust-preventing compound if the block will not be used immediately. A standard diameter piston and piston ring set must be used with a sleeved cylinder bore.
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