2.2.26. Installation of pistons / rods assembled and check of lubricant gaps in bearings of rods


  1. Before installation of pistons/rods assembled walls of cylinders have to be perfectly pure, has to be chamfered the upper edge of each cylinder and the bent shaft has to be established.
  2. Uncover with a rod No. 1 (address the marks made at removal). Remove former inserts of bearings and wipe the surfaces of bearings of a rod and a cover pure, not leaving fibers, with fabric. They have to be perfectly pure.

Check of lubricant gaps of bearings of rods


  1. Clear a back surface of a new top insert of the bearing, then establish it on a rod. Make sure that the ledge of an insert of the bearing coincides with deepening in a rod. Do not hammer a bearing insert into place with the hammer and be very careful not to leave on a surface of scratches or jags. Again be convinced that the ledge of an insert coincides with deepening in a cover, and you do not apply any lubricant. It is essentially important that the interfaced surfaces of the bearing and a rod at this check perfectly pure and without oil.
  2. Establish gaps of piston rings under corners 120 ° to each other.
  3. Put on a piece of a plastic or rubber tube each bolt of a cover of a rod.
  4. Oil the piston and rings pure motive and install on the piston a szhimatel. Leave a skirt of the piston acting on 6 or 7 mm to insert the piston into the cylinder. Rings should be squeezed until they do not appear aflush with the piston.
  5. Turn a bent shaft that the neck of the bearing of a rod No. 1 appeared in LDP (lower dead point). Apply a layer of motive oil on cylinder walls.
  6. Carefully insert a piston/rod assembled into the cylinder No. 1, having directed a tag or a cut to the piston bottom towards an engine front, and rest bottom edge of a szhimatel against the block of cylinders.
  7. Strike the upper edge of a szhimatel of rings to be convinced that it on all circle contacts to the block.
  1. Slightly strike the piston bottom with the wooden handle of the hammer, at the same time directing the end of a rod to a neck of a bent shaft. Working slowly if at advance of the piston on cylinders resistance is felt, immediately suspend pressing. Find what disturbs and remove the cause. Under no circumstances do not use force - it is possible to break a ring and/or the piston.

Piston rings before the entrance to the cylinder can jump out from a szhimatel therefore put pressure on a szhimatel.

  1. When pistons/rods are assembled established, before final tightening of bolts of a cover of a rod it is necessary to check a lubricant gap of the bearing.
  2. Cut off a piece of a plastic wire of the corresponding size, it is a little less than width of the rod bearing, and lay it on a rod No. 1 neck, parallel to an axis of a bent shaft.
  3. Clear the surface of the bearing of a cover of a rod, remove protective tubes from rod bolts and establish a rod cover. Make sure that the tag on a cover coincides with a tag on a rod.
  4. Establish nuts, bolts and tighten with the effort specified in the Size table and adjusting data at the end of the Management. On M10 and M30 engines reach final effort in three stages.

To avoid mistakes in measurement of effort of tightening, apply a face head with thin walls which will not jam between a cover of a rod and a nut. If gets jammed a head between a nut and a cover, then raise a little a head that it did not concern a cover. During this operation do not turn a bent shaft.

  1. Turn off a nut and uncover a rod, being careful not to shift a plastic wire.
  1. Compare width of the flattened-out wire to the scale printed on packing of a wire. Compare value to requirements of the Size table and adjusting data at the end of the Management to be convinced of correctness of a gap.
  1. If the gap differs from demanded, then inserts of bearings can be the wrong size (that means need of acquisition of new inserts). Before making the decision on need of acquisition of other inserts, be convinced that at measurement of a gap between inserts and rods or covers there is no dirt or oil. Also again measure diameter of a neck. If width of a wire was not identical, then the neck can have conicity (watch the Section Check of a Condition of a Bent Shaft).

Final installation of rods


  1. Carefully remove all traces of material of a wire from the surface of a neck and/or the bearing. Be careful not to scratch the surface of the bearing - do it by a nail or edge of a credit card.
  2. Make sure that to the surface of bearings perfectly pure, then apply on both surfaces an even layer of disulfidmolibdenovy lubricant or motive oil. For access to a surface of an insert of the bearing of a rod it will be required to push the piston in the cylinder - at first be convinced that on rod bolts if protective tubes are applied, put on.
  3. Back shift a rod on its place on a neck and uncover with bolts of a rod protective tubes. Establish covers of a rod and tighten nuts / bolts with the required effort.
  4. Repeat the same procedure for other pistons / rods.
  5. Important circumstances is the following:
    • At assembly preserve external surfaces of inserts and internal surfaces of rods and covers in perfect purity.
    • Make sure that in each cylinder the corresponding pistons / rods assembled are installed.
    • The cut or tag on the piston have to be turned to an engine front.
    • Oil walls of cylinders pure.
    • At installation of covers of rods after check of a lubricant gap grease the surfaces of bearings.
  6. After the correct installation of all pistons / rods assembled for verification of obvious jammings by a hand turn several times a bent shaft.
  7. Check a side side play of rods (watch the Section Removal of a Bent Shaft).
  8. Compare the measured side side play to requirements of the Size table and adjusting data at the end of the Management to be convinced of its correctness. If the side side play before dismantling was correct and the initial bent shaft and rods were established, then it has to remain. If the new bent shaft or new rods were established, then the side side play can be wrong. If so, then rods have to be removed and sent for survey to a mechanical workshop.