65637bd9 Installation and check of gaps in conrod bearings


The description concerns only conrod bearings of the standard size. Repair connecting rods are not subdivided into dimensional groups.

New conrod bearings are selected by the codes of dimensional group put on the crankshaft.

Codes of dimensional groups are put or on a crankshaft cheek near a neck of the 1st cylinder (from a chain of the drive of cam-shafts), or on a cheek near a neck of the 4th cylinder (from a flywheel or a drive plate of the hydrotransformer). The code from four figures indicates dimensional groups of conrod necks of the crankshaft, the first figure belongs to a neck of the 1st cylinder, and the fourth – to a neck of the 4th cylinder. The code from five figures concerns to dimensional groups of radical necks of the crankshaft (see subsection

To pick up inserts of conrod bearings, it is necessary to learn dimensional group of a conrod neck of the crankshaft for this cylinder, and then to determine the necessary insert by the enclosed table, being guided on color marking which in the form of a point is applied on a side surface of an insert.

Code on the crankshaft
Color marking of dimensional group of an insert

Check of a gap in conrod bearings

1. Clear an external surface of connecting rods and the surface of boring under inserts in rods and in covers of rods.
2. Having pressed on inserts, lay the top and lower inserts on the places. Make sure that ledges on inserts of the bearing came into selections in a rod (are specified by shooters) and of a rod cover.
3. At installation of inserts it is forbidden to touch a working surface of inserts with fingers. Make sure that the lubricant opening in the top connecting rod was precisely combined with an opening in a rod. If check of a gap is carried out with old inserts, then be convinced that these inserts are established on former places.
4. The gap in conrod bearings can be checked in two ways. When determining a gap it is necessary to collect by the first way covers with rods and conrod bearings, having tracked correctness of mutual orientation of these details. Tighten nuts of conrod covers with the set moment and measure the internal diameter of each collected couple of inserts by means of a nutromer with the arrow indicator or calipers. The gap in radical bearings is defined as a difference of internal diameter of assembled conrod bearings and diameter of the corresponding conrod necks of the crankshaft.
5. The second way (more exact) consists in application of a plastic calibration wire of Plastigage of round section laid on carefully cleared surfaces of conrod necks.
6. Install conrod bearings, it is correct them having oriented. On each conrod neck of the crankshaft put on a piece of a calibration wire.
7. Clear surfaces of connecting rods and establish rods on the corresponding necks of the crankshaft. Establish covers of conrod bearings, having oriented them on the available tags, or the put tags when dismantling.
8. Tighten nuts of covers (see below). When tightening change of provision of a wire is not allowed, the crankshaft provorachivaniye is also not allowed.
9. Uncover rods, without allowing at the same time turn of the crankshaft or shift of a calibration wire. Compare width of the flattened wire to a scale on packing and define a gap in radical bearings.
10. If the gap differs from standard, then the wrong selection of connecting rods can be the cause (or their increased wear if the inserts which were in operation were checked). Before coming to a conclusion about need of replacement of inserts be convinced that between surfaces of covers or rods and an insert at measurement there were no dirt or oil. If width of the flattened wire from one edge is more, then it indicates conicity of a conrod neck.
11. If the gap differs from norm at measurements with old inserts, then repeat measurements with new inserts. If and with new inserts the gap exceeds norm, then it is necessary to address for consultation in service of car service of the dealer, or the specialist in this engine to get advice how to work further. It is possible that it is necessary to pereshlifovat conrod necks of the crankshaft and to replace inserts repair.
12. If necessary get inserts of the corresponding dimensional group and repeat the procedure of measurement of a gap in conrod bearings.
13. Upon termination of scratch out a nail or a wooden chip the remains of a calibration wire from radical necks of the crankshaft, without having damaged at the same time their surface.

Installation of conrod and piston group

The further description is kept in that assumption that assembly will be carried out after the crankshaft assembled with all radical bearings and with covers is installed (with a framework of covers).

1. Be convinced of correctness of installation of conrod bearings (see subitems 4 and 5). If new bearings are installed, then carefully remove the remains of the preserving lubricant, their washout in kerosene. Dry wipe rods and bearings with the fabric which is not leaving pile.
2. Be convinced of the correct arrangement of joints of piston rings and squeeze rings special adaptation.
3. Grease cylinders, pistons and rings, then lay out pistons assembled with rods in that sequence in which these details will be established on the engine.
4. Begin assembly with the 1st cylinder. Be convinced of the correct arrangement of joints of piston rings (see subsection and squeeze rings special adaptation.
5. Insert the piston assembled with a rod into the first cylinder. Orient the piston so that the tag on the piston bottom (in the form of an arrow or line) was turned towards a cover of the chain drive of cam-shafts. Slightly knock on the piston with the handle of the hammer or wooden whetstone that the piston came into the cylinder and the bottom of the piston it was made even to the demountable plane of the block of cylinders.
6. Make sure that connecting rods are established correctly and plentifully grease inserts and a conrod neck of the crankshaft. Carefully, not to damage the surface of the cylinder, attract a rod to a crankshaft neck. Dress a rod cover with an insert and tighten nuts by hand. Keep in mind that the planes on a rod and on a rod cover on whom tags are applied have to be combined (it means that adjusting ledges of conrod bearings are located opposite to each other).
7. Tighten nuts of conrod covers with the moment of the 1st stage of an inhaling by means of a dynamometer key and a face head (a photo at the left). Then tighten nuts on a corner of the 2nd stage of an inhaling, or in the absence of a key with an angular scale, tighten with the moment of the 2nd stage (a photo on the right).
8. Turn the crankshaft and check freedom of its rotation. If new details are established, then the noticeable constant resistance to rotation of the crankshaft has to be felt, however the crankshaft has to be turned smoothly, without jammings.
9. Similarly install other pistons and rods.
10. Establish a head of cylinders, a chain (or chains) the drive of cam-shafts and the oil pallet.