Connections are detachable, the main type is threaded and one-piece - riveted and welded. All threaded fasteners to be installed must be clean, straight, with intact threads and strict edges of the heads of the bolts and nuts on which the wrench heads are installed.
Special self-locking nuts with nylon and fiber inserts cannot be reused and must be replaced with new ones.
Note. Damaged fasteners (nuts, bolts, studs, washers) must be replaced.
Rusted bolts and nuts should be pre-treated with a penetrating agent such as turpentine or special fluids and allowed to stand before loosening to facilitate removal. In emergency cases, it is allowed to use a chisel or a hacksaw, followed by the removal of fastener residues from the threaded part. flat (lining) and lock washers must always be reinstalled in the same order and in the same manner during reassembly as during disassembly and removal.
Fastener size
When assembling the car, fastening elements are used, made as per inch system of measures (English system or SAE standard), and according to a more universal - the metric system of measures. For all their similarity, it is unacceptable to confuse them.
Pic. 2.1. Fastener marking
Both metric and standard bolts can be identified by looking at the heads (pic. 2.1).
The tightening torques of threaded connections, unless they are specifically specified in the technical specifications, are determined depending on the thread diameter in accordance with Table. 2.1.
Table 2.1. Permissible tightening torques for threaded connections
Thread diameter, mm | Tightening torque, Nm |
6 | 6-9 |
8 | 14-17 |
10 | 30-35 |
12 | 55-60 |
14 | 80-90 |
16 | 120-140 |
18 | 160-190 |
20 | 230-270 |
22 | 300-360 |
24 | 420-480 |
Bolt thread must protrude from nut (except in special cases) for 2-3 threads.
Cotter pins must not protrude from the slots of the nuts. The ends of the cotter pins must be separated and bent one onto the bolt and the other onto the nut. When assembling, blow the fuel line and brake system drive tubes with compressed air and roll them with a ball of the appropriate diameter.