21499128 Volvo.Penta Shaft

Modification of Flywheel Housing Equipped with Core Plug
To install this timing control system on this engine, it will be necessary to install a magnetic pickup to be used as a crankshaft angle sensor.* Some engines will have a flywheel housing that already has a threaded hole, with a plug in it, that can be used for installation of the magnetic pickup. The modification procedure given here will not be necessary for those engines. It will be necessary, however, to remove the plug and install the magnetic pickup as described later in this instruction.* For those engines that are equipped with a core plug [refer to core plug (1) in the illustration that follows] it will be necessary to do the complete flywheel housing modification procedure given here. In this procedure, a new plug will be needed for installation in the flywheel housing. A special template is needed to accurately identify the location to drill and tap two holes in this new plug. Accurate location of both of these holes is necessary. One hole is used for installation of a bolt to retain the newly installed plug and keep it from turning. The second hole will be used for installation of the crankshaft angle sensor.The new plug and the template, used for this modification procedure only, can be obtained by contacting Engine Division Service Engineering, Caterpillar Inc. It will be necessary to return the template to Service Engineering after your modification is completed. 1. Remove core plug (1) from hole (A) in the right front face of the flywheel housing. Install the new plug in hole (A).2. Remove cover plates (3) and (4). Removal of cover plate (4) is necessary to observe inside the flywheel housing during the following procedure. 3. Put template (6) in position on the flywheel housing, over new plug (5) [installed in hole (A) in Step 1]. The template has a hole that permits it to fit over plug (2) and its mounting boss.4. Align the two bolt holes [locations (C) and (D)] in the template, with the two bolt holes that were used to fasten cover plate (3) to the flywheel housing.Use one 0S1608 Bolt with a 5M2894 Washer at location (C) and one 0S1591 Bolt with a 5M2894 Washer at location (D), to fasten the template in position on the flywheel housing. In the procedure that follows, holes will be drilled in the plug that was installed in the flywheel housing in Step 1. It will also be necessary to cut threads in the drilled holes. Do not permit metal chips to fall inside the flywheel housing during this procedure.
DO NOT permit the drill bit to come in contact with the front face of the engine flywheel. It may be possible to insert something through the hole for cover (4), to use as a buffer between the drill bit and the flywheel, to prevent the drill bit from coming into contact with the flywheel. (It may also be possible to devise a depth gauge to control hole depth.) Any contact of the drill bit with the flywheel will produce an incorrect sensing hole for the crankshaft angle sensor, and will require the installation of a new flywheel.
5. Drill a 5.20 mm (0.20")Ø hole at location (E) through the plug and into the flywheel housing.Remove the drill bit from the drill chuck. Turn the drill bit around and put the blunt end in the hole just drilled to hold the plug in position.6. Drill a 14.50 mm (.570")Ø hole at location (B).7. Remove the template from the flywheel housing. Make sure to remove all metal chips from both inside and outside the flywheel housing.8. Use a 1P3021 Tap to cut 1/4"-20 threads in hole (E).Install a 0S1615 Bolt with a 5P0537 Washer in hole (E) to secure the plug to the flywheel housing.9. Use a 1P3034 Tap to cut 5/8"-18 threads in hole (B). Make sure to remove all metal chips from both inside and outside the flywheel housing.Installation of 9Y4842 Cover and Control Group on 3512 Engines
The parts needed are given in the following parts list. The illustrations give the location for the installation of the two 9Y3904 Covers that are needed. Before installation of the new covers, remove the corresponding original covers and their gaskets.Make sure all of the original O-ring seal is removed and the sealing surface of the cylinder block is completely clean. This will ensure a good seal with the new O-ring seal.
Camshaft Cover Installation Location (Left Side): A. Installation location for a 9Y3904 Cover (1) on a 3512 Engine. B. Rear face of the cylinder block.
Camshaft cover Installation Location (Right Side): B. Rear face of cylinder block. C. Installation location for a 9Y3904 Cover (1) on a 3512 Engine.
F. Tighten to a torque of 10 2 N m (90 18 lb in). H. Flywheel housing. K. Cylinder block.1. Adjust sensor (magnetic pickup) (4) at location (G) (on top of flywheel housing) as follows:* With the engine stopped, thread magnetic pickup into the hole until the magnet core is against the teeth of the flywheel gear, then turn it back out 1/2 1/10turn* Tighten the locknut to a torque of 13 1.0 N m (125 9 lb in). Clearance between the end of the magnetic pickup and the flywheel gear teeth should be 0.56-0.84 mm (0.02-0.03").2. Adjust sensor (magnetic pickup) (4) at location (J) (in the front face of the flywheel housing) as follows:* With the engine stopped, thread magnetic pickup into the hole (in the front face of the flywheel housing) until the magnet core is against the front face of the flywheel, then turn it back out 1/2 1/10 turn* Tighten the locknut to a torque of 13 1.0 N m (125 9 lb in). Clearance between the end of the magnetic pickup and the front face of the flywheel should be 0.56-0.84 mm (0.02-0.03").3512 Spark Ignited Generator Set Engine
These engines can have any one of three ignition systems.