13720 Mercruiser BUSHING

5-1 A Type Injection Pump <4D31, 4D30, DR (Nippondenso Products) >
5-1-1 Removal
1 Fuel hose2 Injection pipe3 Leak off pipe <4D31>4 Oil pipe5 Injection pump stay <4D31, 6DR5>6 Injection pumpHold the injection pump by hand, and remove five timer case attaching bolts.Then, remove the injection pump, pulling it rearward.Use of Socket Wrench (special tool) will make the removal of timer case attaching bolts easier. 5-1-2 Disassembly
For disassembly of parts with an encircled number, see following items.Inspection items marked with * must be checked before disassembly 1. Keep disassembled parts neatly arranged for each cylinder.2. Keep plunger, plunger barrel, and delivery valve in gas oil. (1) With the auto timer and timer case removed, install the injection pump on Pump Mounting Base and Pump Setting Angle (special tools). (2) Using Box Wrench (special tool), remove the feed pump.(3) Remove the governor and cover plate. RSV governor ... (See 5-3-1)RU governor ... (See 5-5-1)MZ governor ... (See 5-6-1)(4) Measure the control rack sliding resistance. Turn camshaft to ensure that the resistance is up to specification in any position.If the nominal value is exceeded, possible causes are as follows:* Damage on control rack and defective tooth* Defective pinion tooth, pinion in contact with housing* Excessively tightened delivery valve holder (5) Using Coupling and Round Nut and Holding Spanner (special tools), turn the camshaft to bring the tappet to TDC. Insert Tappet Insert (special tool) in the tappet service holes successively to separate the camshaft from the tappet. (6) Mount Camshaft Clearance Gauge (special tool) on the camshaft to measure the end play. (7) Remove the camshaft, tapping it with a soft hammer from the governor end. On 6DR5, before removing the camshaft, remove center bearing. 1. Make sure that the cams on camshaft are not in contact with the tappet.2. Install the flyweight round nut at the end of camshaft to protect threads. (8) Accessing from the bottom of the pump, insert Roller Clamp (special tool) to push up the tappet. Remove Tappet Insert (special tool). (9) Move the tappet with Roller Clamp (special tool), and insert Tappet Clamp (special tool) into the camshaft hole to take out the tappet. (10) Insert Plunger Clamp (special tool) from the bottom of the pump and fix its end to the lower spring seat. Then, withdraw the special tool with plunger. When removing, ensure that the notch in the lower spring seat (for inserting the plunger) faces up to prevent the plunger from dropping.(11) Measure the backlash between control rack and pinion. If the limit is exceeded, replace parts. (12) Remove the lock plate and remove the delivery valve holder with Box Spanner (special tool). Then, remove the stopper, delivery valve, and spring. (13) Using Delivery Valve Extractor (special tool), remove the delivery valve. (14) Remove the plunger barrel. Keep a plunger and plunger barrel pair in gas oil.5-1-3 Inspection and Correction
(1) Plunger and Plunger Barrel After cleaning in gas oil, check if the plunger falls smoothly in the plunger barrel under its own weight.Use the following procedure for the inspection:* Tilt the plunger barrel approximately 60°.* Pull the plunger about 10 to 15 mm and let it go.* Turn the plunger to check on several more points.Replace the plunger if it does not fall.(2) Delivery Valve Clean the valve and valve seat of the delivery valve in gas oil and check for wear.Seal off the bottom of the valve seat with a finger, and press the piston with a finger. If the piston bounces back when released, the valve is in good condition. If not, replace the valve as it must be badly worn. With the engine provided with the Ungleigh cut <4D31>, the above procedure is not effective since the piston does not spring back. (3) Tappet Apply a dial indicator to the tappet roller and check for over-all clearance by moving the roller up and down with a rod. If the clearance exceeds the limit, replace the tappet assembly. Measure the clearance between the tappet and pump housing and, if the limit is exceeded, rplace parts.(4) Lower Spring Seat Check the lower spring seat surface in contact with the plunger for wear. If the limit is exceeded, replace the lower spring seat.(5) Plunger Spring and Delivery Spring Valve Measure the squareness of the springs and, if the limit is exceeded, replace.(6) Replacement of Taper Roller Bearing Inner RaceUsing gear puller, remove the rolle and inner race from the camshaft.For installation, put ring and shim and the press-fit the bearing. Use shims of nearly the same thickness on both ends of the camshaft. Outer RaceTo remove the outer race on the cover end, use Camshaft Outer Race Remover (special tool).Install by using a press.(7) Camshaft Bend (Runout) Support the camshaft with a V-block at its ends (or the center holes at both ends), and check for bend at the center with a dial indicator.If the limit is exceeded, correct with a press or replace.5-1-4 Reassembly
(1) Mount the control rack and rack guide screw. Make sure that the rack moves smoothly. Check also to ensure that the rack does not turn when so attempted. (2) At installation, ensure that the knock pin fitted into the pump housing is aligned with the locating notch in the plunger barrel. Make sure that the knock pin projects by about 0.7 mm from the housing. If the projection is smaller than that, drive pin out from the housing side. Note that the pump housing area must be cleaned, into which the plunger barrel is inserted. (3) With a new gasket installed in the delivery valve, drive the valve into position until it is held tightly against the plunger barrel top surface, using Delivery Valve Gasket Installer (special tool). (4) Fit the delivery valve spring and stopper into position, and temporarily tighten the delivery valve holder. (5) With the control rack set at the center, install the control pinion and control sleeve. 1. Install with the control pinion joint and the control sleeve notch facing to your side.2. Every