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Disassembly and installation of crankshaft front and rear oil seals of Hitachi excavator
Class:Industry News Pubdate:2020-09-04 10:35:38 Browse:0 [Back]

There are 11 steps to remove the crankshaft front oil seal of Hitachi crawler excavator


(1) Drain the coolant.


(2) Remove the starter.


① Disconnect the grounding cable of the starter.


② Loosen the upper and lower mounting nuts from the starter and remove the starter from the flywheel housing.


(3) Disconnect the upper radiator hose on the engine side.


(4) Disconnect the radiator side coolant reservoir hose.


(5) Disconnect the engine side radiator lower hose.


(6) Remove the radiator (with fan shroud) and remove the right and left brackets.


(7) Loosen the 4 mounting bolts and remove the fan assembly.


(8) Remove the fan belt.


(9) Install the crankshaft stop at the installation position of the starter on the flywheel housing to prevent the crankshaft from rotating. Loosen the pulley nut and remove the crankshaft pulley.


(10) Remove the front oil seal of the crankshaft and remove the oil seal with a screwdriver or similar tool to avoid damaging the contact table of the oil seal on the front cover and shaft.


(11) Remove the front oil baffle ring with the oil deflector. Note: the oil retaining ring and oil seal must be replaced as a set, which can intelligently create a grand view, multi-functional accessories of construction machinery and a complete series of mining machinery equipment.


Eight steps for the installation of crankshaft front oil seal of Hitachi crawler excavator:


1. Install the front oil deflector


(1) Install the front oil baffle ring with the installation device and positioning tool.


(2) Install the oil deflector to the end of the connector.


(3) Install the coupling onto the crankshaft.


(4) Install the oil deflector on the connector. Tighten the central bolt until the sleeve contacts the connector stop.


(5) After pressing in the oil baffle ring, make sure that the distance between the crankshaft end face and the oil baffle ring meets the requirements.


Note: the oil baffle ring and oil seal must be replaced as a set.


2. Install the crankshaft front oil seal


(1) Install the oil seal with the oil seal installer and positioning tool.


(2) Install the connector to the crankshaft with the fixing bolt.


(3) Apply oil to the lip of the oil seal and install it on the front connector.


(4) Put the front connector ring into the sleeve and fix the sleeve on the connector with the central bolt and washer.


(5) Tighten the bolts until the sleeve contacts the connector for pressing the front oil seal.


(6) After pressing the front oil seal, check the depth from the crankshaft end surface to the oil seal, and check whether the oil seal deflects.


3. Install the torsional damper


(1) Install the torsional damper on the crankshaft pulley.


(2) Tightening, tightening torque: 48n. M.


4. Install crankshaft pulley


(1) Apply oil to the thread of fastening bolt.


(2) Align the thrust pin on the crankshaft and install the crankshaft pulley.


(3) Tightening, tightening torque: 200N. M.


5. Fan mounting belt


(1) Check the tightness of the fan belt.


① Install the fan belt and check the tightness of the fan belt. When 98n pressure is applied in the middle of the belt, use a ruler to check whether the belt sag is within the specified range.


② Check the belt for damage.


(2) Adjustment of fan belt tightness.


① To adjust the tightness of the fan belt, loosen the adjusting bolt of the alternator and adjust the fan belt by moving the generator.


② Tighten the fixing bolt with the tightening torque of 24N. M for bolt 2 and 40n. M for bolt 3.


6. Fasten the fan assembly


Tighten the fan assembly according to the specified torque, tightening torque: 24N. M.


7. Install radiator


(1) Install the radiator and connect the lower radiator hose.


(2) Connect the reservoir hose.


(3) Connect the radiator upper hose.


(4) Fill the radiator with coolant.


8. Install the starter


(1) Install the starter into the flywheel housing with nuts and tighten according to the specified torque, tightening torque: 76n. M.


(2) To connect the grounding cable of the starter, it is necessary to connect the front-end accessories such as quality crushing hammer, etc.


There are three steps to remove the crankshaft rear oil seal of Hitachi crawler excavator


1. Remove flywheel


2. Remove the crankshaft rear oil seal


Remove the oil seal with a screwdriver or similar tool to avoid damaging the oil seal contact surface on the flywheel housing and shaft.


3. Remove the oil deflector


Remove the oil baffle ring with the oil deflector. Note: if the oil seal has been removed, the oil seal and oil deflector must be replaced as a set.


Two steps for the installation of crankshaft rear oil seal of Hitachi crawler excavator:


1. Install the rear oil deflector


4hk1 engine oil seal installation tool 5-8840-2703-0, 6hk1 engine oil seal positioning tool 8-94396-856-0. Install the rear oil baffle ring with the oil seal installation device and oil seal positioning tool.


(1) First install the oil deflector to the end of the connector, and then install the connector to the crankshaft.


(2) Fit the oil deflector onto the connector. Tighten the central bolt until the sleeve contacts the connector stop.


(3) After pressing the oil baffle ring, ensure that the distance between the crankshaft end face and the oil baffle ring meets the requirements. The distance between the crankshaft end face of 4hk1 engine and oil baffle ring is (17.3 + 0.3) mm and B: (10.8 + 0.1) mm. The distance between crankshaft end face and oil baffle ring of 6hk1 engine is (17 + 0.3) mm.


Note: the oil retaining ring and oil seal must be replaced together.


2. Install the crankshaft rear oil seal


Install the rear oil seal with the oil seal installer and positioning tool.


(1) Place the collar on the retaining bolt and install the connector on the crankshaft.


(2) Apply oil to the oil seal lip and put it into the rear connector.


(3) Put the rear connector into the sleeve and fix it with the central bolt.


(4) Press the oil seal by tightening the center bolt until the sleeve contacts the connector.


(5) After pressing the rear oil seal, confirm that the distance between the crankshaft end face and the oil seal meets the requirements. 4hk1 engine: (7.8 + 0.3) mm, 6hk1 engine: (7.5 + 0.15) mm.