Contents: Mating surfaces and gaskets ↓ Sealing cuffs ↓ Threaded connections ↓ Locknuts, washers and other means of…↓ Special tools or devices ↓
When servicing or repairing, please follow the recommendations and rules below. This will contribute to the efficient and high-quality execution of work.
Mating surfaces and gaskets
When disassembling mating parts, never insert screwdrivers or any similar tools between the mating surfaces. This can lead to serious damage, which after assembly ends in leaks of oil, coolant, etc. To separate, usually tap the perimeter of the mating surfaces with a hammer made of a soft material, which allows the gasket to be separated. However, it should be borne in mind that this method is not suitable for disassembling connections in which dowel pins are used to align the parts being connected.
If a gasket is required between the mating surfaces of two parts, a new gasket should always be installed during assembly. The gasket must be installed dry unless otherwise stated in the assembly manual. Before installation, ensure that the mating surfaces are clean and dry and that there are no traces of the old gasket. When cleaning mating surfaces, use a tool that does not degrade the surface quality and remove any burrs or nicks with an oiled abrasive block or a fine-cut file.
Make sure all threads are clean and do not allow thread locking compound to come into contact with them unless otherwise specified in the assembly instructions.
Make sure all openings, passages or pipes are clear and blow them out with compressed air.
Sealing cuffs
The cuff can be removed by prying it out with a wide-head screwdriver or similar tool. For the same purpose, you can screw several self-tapping screws into the cuff and pull the cuff out using pliers or another similar tool.
In any case and regardless of the reason for removal, the removed cuff must be replaced with a new one upon installation.
The very thin sealing lip of the cuff can be easily damaged and will not perform its function if dirt, scratches, nicks or grooves are not completely removed from the surface with which it contacts. If the surface of the part cannot be restored and the manufacturer has not provided for some movement of the seal relative to the surface, the part must be replaced.
To avoid damaging the sealing edges of the cuff, protect them from contact with any parts during installation. Use masking tape or a tapered mandrel if possible. Before installation, lubricate the cuff with oil. When installing a double-lip seal, fill the space between the lips with grease.
Unless otherwise specified, when installing the cuff, its sealing edges must face the lubricant whose leakage they prevent.
To press the cuff in, use a piece of pipe of the appropriate diameter with machined ends or a wooden block, and if the seat for the cuff is equipped with a flange, the cuff should be installed until it stops against this flange. If the seat does not have a flange, the cuff must be installed flush with the outer surface of the housing into which it is installed (unless otherwise stated).
Threaded connections
Nuts, bolts and screws are the parts where corrosion usually occurs. If the threaded connection does not loosen, moisten the connection area with penetrating oil, kerosene or another similar liquid and leave it for a while. You can try using a screwdriver or an impact wrench. If none of these methods help, you can try gently heating the connection. If this doesn't help, you'll have to use a hacksaw or chisel.
The pins are usually turned out in the following way. Thread two nuts onto the stud, one next to the other, and tighten them together. Then, using a wrench to turn the lower nut, unscrew the stud. Studs or bolts that have broken below the surface of the part they are screwed into can sometimes be removed using a stud extractor. Before screwing a stud or bolt into a blind hole, first make sure the hole is completely clean of oil, grease, water or other liquid. If this is not done, the housing may be destroyed due to the hydraulic pressure that occurs when screwing in the bolt or stud.
When tightening the castle nut, tighten the nut to the specified torque and then tighten it to the nearest cotter pin hole. Never loosen the nut to align the cotter pin holes unless specifically instructed to do so in the assembly instructions.
If it is necessary to check the tightening torque of a bolt or nut, loosen it by a quarter turn, then tighten it again to the specified torque. However, this cannot be done if the fastener has been further tightened to the required angle after being tightened with a torque wrench.
For some threaded connections, especially for cylinder head bolts or nuts, the final tightening stage is not specified as a torque, but as an angle by which the fastener must be tightened. Typically, a relatively small tightening torque is specified for screwing in the bolts in a certain sequence, and then the bolts are tightened in one or more steps to the specified angles.
Locknuts, washers and other means of preventing loosening
Any fastener that will rotate relative to the part or housing when tightened must always be fitted with a washer.
Spring or split washers in critical joints such as the big-end bearing should always be replaced. Bend washers, if they have ever been bent back to free a nut or bolt, should also always be replaced.
Self-locking nuts can be used repeatedly in non-critical connections if resistance is felt when tightening when the locking part of the nut enters the thread of the stud or bolt. However, it should be noted that with prolonged use, self-locking nuts gradually lose their effectiveness and also need to be replaced periodically.
Cotter pins should always be replaced with new ones that fit the hole size.
If a thread locking compound has been applied to the threads, it should be removed with a wire brush and solvent, and fresh compound should be applied during assembly.
Special tools or devices
Some repair procedures described in this manual require the use of special tools and equipment such as presses, two- or three-jaw pullers, spring compressors, etc. Where possible, equipment that can be used in place of the special tools provided by the manufacturers is described. In some cases, when an alternative is excluded, it is necessary to resort to using a proprietary special tool. This is done for safety reasons, as well as to ensure that repairs are carried out efficiently. If you are not very skilled or if you have not fully understood the procedures described, never attempt to do this without using a special tool (devices), if the procedure description provides for its use. You can not only get injured, but also damage expensive parts.