The crankshaft is considered one of the key parts of the power unit. How correctly it functions largely depends on the condition and proper selection of the main and connecting rod bearings. In this material, we will explain in an accessible way how to select crankshaft bearings, including for VAZ cars, and what points you should keep in mind to avoid mistakes.

What role do crankshaft bearings play

Bearings are thin metal liners that are mounted between the crankshaft and the supporting journals of the cylinder block. Their main task is to ensure smooth rotation of the shaft and minimize friction. If knocking sounds appear in the engine, oil pressure drops, or accelerated wear of parts is observed, it is likely time to replace these elements.

How to understand which bearings are required

First of all, you need to accurately determine the engine modification of your car. This is especially relevant when it comes to selecting bearings for a VAZ crankshaft, since different models have different tolerances. To obtain the necessary information, you should use the VIN code or factory technical documentation.

Key characteristics of bearings:

  1. Crankshaft journal diameter. After grinding the shaft, this parameter may differ from the original factory value. It is necessary to measure the diameter using a micrometer.
  2. Dimensions of the beds in the block. In some cases, it may be necessary to install repair bearings that have a greater thickness.
  3. Type of bearings. They are main and connecting rod bearings. The choice depends on which part of the mechanism is worn.
If you are in doubt about how to correctly select bearings for a car crankshaft, it is better to seek help from an experienced engine mechanic or a specialized service center.

Features of selecting bearings for VAZ

For VAZ cars (for example, models 2101-2107, 2110 and others), standard or repair bearings are most often used. They can have the following markings:
  • 0 (standard size)
  • 0.25
  • 0.5
  • 0.75
  • 1.0 mm (repair sizes)
After grinding the crankshaft, it is necessary to select bearings that correspond to the same repair size. For example, if the shaft was machined to 0.5 mm, then you need to take bearings with the marking 0.5. It is also important to pay attention to the manufacturer. Preference should be given to proven brands such as Glyco, Kolbenschmidt, AvtoVAZ or TZA.

What is the risk of an error when choosing bearings

If the clearance between the shaft and the bearing turns out to be excessive, the oil film will not be able to form properly, which will lead to rapid engine failure. If the clearance is too small, overheating, scoring, and even seizure are possible. Therefore, before selecting bearings for a car crankshaft, especially for VAZ models, you need to make accurate measurements, get advice from a specialist, and not try to save on quality. Choosing bearings is not the most difficult task, but it is extremely responsible. Make sure you know all the parameters of the crankshaft and block beds, determine the required type of bearings, and strictly follow the manufacturer's instructions. This approach will help preserve the engine's service life and avoid expensive repairs in the future.