Genuine Audi 90 Crankshaft

Audi 90 Crankshaft Parts and Q&A

• Crankshaft
  078-105-101-AB
  Q: How to remove and reinstall the crankshaft components on Audi 90?

  A:

  The engine is out of the car, the first task is to take out the Pistons and connecting rods with the big-end bearings and their corresponding rods being kept so as to fit them in the correct locations again. The second step is to take off the Oil Pump and rear oil seal together with the housing. Ensure that every main bearing cap is identified by a number based on the location in front of the engine and unscrew and remove the bolts on caps 1, 2, 3, 5 and 6 then remove the caps. With cap No 4 still attached, the crankshaft endfloat is checked with a feeler blade between the thrustwasher and the crankshaft web to determine the degree of wear in the thrustwashers against the stipulated endfloat levels. Unscrew and take off the No 4 main bearing cap and maintain each bearing shell with the matching bearing cap. Lift off the crankshaft out of the crankcase and take off the bearing shells and identify them with their locations. On certain models the rear spigot bearing is retained on the Flywheel by two circlips. Place the cylinder block on the bench with the crankcase open and then find the upper main bearing shells in the crankcase making sure that the tags fit in the cut-outs and oiling the shells. In case of using old shells, ensure that they are in the right places with oil grooves. Install the crankshaft into the crankcase and find the lower main bearing shells in the main bearing caps, all of which are plain. Install the thrustwashers, one on each side, of No 4 cap, with a little grease holding them in place with the oil grooves facing outwards. Oil bearing shell, install No 4 main bearing cap, place bolts, and screw them to a given torque. Check the endfloat with a feeler blade or dial gauge to check that it is in specification. Wipe the rest of the main bearing shells, insert the caps in their proper places and install the bolts and tighten them to the required torque. Lastly, ensure that crankshaft is in free rotation, then replace rear oil seal and housing, oil pump, and pistons and connecting rods.
• Crankshaft
  034-105-101-S
  Q: How should the crankshaft be cleaned and examined for wear and damage on Audi 90?

  A:

  Check the crankshaft and inspect it against wear and damage, scoring the crankpins and main bearing journals. In case the engine is of high mileage and crankshaft needs to be worked upon, consulting an Audi dealer or crankshaft refinishing expert is recommended to get the regrinding advice. When refitting the crankshaft, it is best to fit a new set, unless the bearing shells and thrustwashers are almost new. In the event that Plastigage is available, the running clearance of existing bearings may be checked by positioning a strip over the crankshaft journal, fitting the bearing and measuring the width of the strip removed. In manual gearbox models, look in the rear of crankshaft at the needle bearing, and see whether it is excessively worn, and requires an extractor tool to be re-fitted. Prepare the recess and drive in the new bearing with either metal tubing, or socket, the lettered side facing upwards and the bearing recessed to a depth of 1.5 mm (0.059 in). Short engines are equipped with crankshafts, which have a needle bearing, to clear the torque converter, the bearing has to be removed when mounting the engine to an automatic transmission model.