4.2.18. Installation to the place of the crankshaft and measurement of a radial gap of radical bearings

Choice of new inserts of bearings

Classification of inserts of radical bearings is carried out on their thickness (address the Section Survey of Radical Bearings and Bearings of the Lower Head of a Rod). Pay attention that for the amount of the 2nd repair it is possible to mix various thickenings of inserts for achievement of the correct radial gap. Begin the procedure with two thinnest inserts then in case the gap is too big, establish 1 thick insert and 1 thin and again measure a gap. If the gap was too big again, establish 2 thick inserts.

Measurement of a radial gap of radical bearings


1. Smooth out backs of inserts of bearings and their bed in the block of cylinders and in covers of radical bearings.
2. Insert inserts of bearings on the places, make sure that the ledge on each insert coincided with a notch in the block of cylinders or in a cover of the radical bearing. Try not to touch a working surface of inserts with fingers.
3. The radial gap can be measured by two methods.
4. The first method (which is more difficult feasible as demands use of set of internal micrometers or the internal / external extending caliper) assumes installation of covers of radical bearings in the block cylinders / case with the inserts established in them. After tightening of fixing bolts with the required effort measurement of internal diameter of each couple of inserts of bearings is performed (the crankshaft at the same time does not need to be installed). After measurement of diameter of each corresponding neck of the crankshaft for receiving a radial gap it is necessary to subtract from the first result of the second.
5. The second (more exact method) assumes to use the product called by the plastic measuring instrument (Plastigauge). The measuring instrument represents thin plastic thread of absolutely round section which is crushed between an insert of the bearing and a neck of the crankshaft. After removal of a cover and an insert width of the crushed thread can be measured with application of the special scale applied on set packing. The gap is determined by width of the crushed measuring instrument thread. Measuring set can be acquired in representative office of Saab or in a workshop on car repairs. When using of the plastic measuring instrument it is necessary to work, the image described below.
6. After installation to the place of the top inserts of radical bearings carefully install into place the crankshaft. Do not apply any lubricants at this stage; bearing necks of the crankshaft and a surface of inserts of bearings have to be absolutely pure and dry.
7. Cut several pieces of plastic thread of the required size (length of each piece has to be slightly less than width of the radical bearing) and to lay each piece on the corresponding neck of the crankshaft coaxially with a neck. The piece of plastic thread has to be laid approximately on 6 mm in one of the parties from the central line of a neck.
8. After installation to the place of the lower inserts of radical bearings establish to the place of a cover of radical bearings and tighten bolts in the progressing order with the required effort. Be careful, do not shift at the same time thread of the measuring instrument and do not turn the crankshaft during the procedure of measurement.
9. Give bolts and uncover radical bearings, observing at the same time extreme care not to break the crushed threads of the measuring instrument or not to turn the crankshaft.
10. Compare width of the crushed plastic thread on each neck to the scale printed on set packing. The measured size shows gap size in the bearing. Compare the size of the measured gap to the values given in Specifications at the beginning of this Chapter.
11. If the gap considerably differs from expected, then inserts of bearings can be the wrong size (or excessively worn-out if old inserts are established). Before coming to the conclusion that it is necessary to establish inserts of other size, once again make sure that at measurement on a neck of the crankshaft and on inserts dirt or oil did not get. If the crushed plastic thread of the measuring instrument is wider since one end, than from another, then it indicates existence of conicity of a neck of the crankshaft.
12. In case the size of a gap lies out of the limits set by Specifications, pick up thickness of inserts for providing the required gap. When calculating of the required gap you remember that it is always better to be mistaken towards the lower bound established by Specifications as in the course of wear of an insert thickness of a gap will increase.
13. If it is necessary, establish inserts of the required size and repeat the procedure of measurement of a gap in the bearing.
14. In conclusion carefully scratch out the crushed thread of the plastic measuring instrument from necks of the crankshaft and inserts of bearings. For this purpose use a nail or a wooden or plastic scraper which cannot damage the surface of the bearing.

Final installation of the crankshaft


1. Again carefully take out the crankshaft from the block of cylinders. On B204 and B234 engines establish into place a rotor of the sensor of position of the crankshaft, (if removed) and tighten screws.
2. By means of dense lubricant fix the top persistent washers from each party of the top bed of the central radical bearing; make sure that oil channels on each persistent washer look outside (from the block of cylinders).
3. Establish into place inserts of covers of radical bearings as it is described above. In case of installation of new inserts make sure that all traces of protective lubricant with use of kerosene or other suitable solvent are removed from them. Dry wipe inserts and rods pure, not ворсящейся with rags. Slightly grease each insert in the block cylinders / case with pure motive oil.
4. Lower into place the crankshaft so that cranks of the 2nd and 3rd cylinders fell into a state of the top dead point (TDP). At the same time cranks of the 1st and 4th cylinders will appear in the lower dead point (LDP), prepare for installation to the place of the 1st piston. Measure a longitudinal side play of the crankshaft (see the Section Survey of the Crankshaft).
5. Grease inserts in covers of radical bearings with pure motive oil. Make sure that adjusting ledges on inserts were combined with the corresponding deepenings in covers.
6. Establish covers of radical bearings on the places, watching that they were installed correctly (deepenings under ledges of inserts of bearings in the block and in covers have to appear on the same party of the bearing). Freely insert fixing bolts.
7. In the progressing order tighten bolts of covers of radical bearings with the required effort by means of a dynamometer key.
8. Make sure that the crankshaft rotates freely.
9. Install pistons with rods assembled as also measurement of a gap in the bearing of the lower head of a rod is described in the Section Installation to the place of assemblies of pistons with rods.
10. Before installation of a casing of a back epiploon of the crankshaft establish in a casing a new epiploon (see the Part Repair of the engine without its extraction from the car).
11. For installation of an epiploon in a casing use a kiyanka and wooden whetstone, or the epiploon can be inserted in a vice with use of wooden whetstone.
12. Apply suitable sealant on contact surfaces of a casing of a back epiploon of the crankshaft, then grease with a small amount of oil sponges of an epiploon and where it is necessary, install the directing plugs. Establish a casing on a back part of the block of cylinders.
13. In order to avoid damage of an epiploon at putting on it on the crankshaft make a guide of a plastic container or wrap up the end of the crankshaft an adhesive tape.
14. After installation of a casing on the place remove a guide or an adhesive tape, then insert bolts and tighten them with the required effort.
15. Establish into place a flywheel / a driving disk, the maslozabornik / filter / the giving tube and the pallet of a case (see the Part Repair of the engine without its extraction from the car of this Chapter).
16. Where removed, establish into place a head of the block of cylinders (see the Part Repair of the engine without its extraction from the car).
17. Establish a distributive chain and an asterisk (see the Part Repair of the engine without its extraction from the car of this Chapter).