Manual Transmission/Transaxle: Testing and Inspection
General Inspection
1. Inspect transmission case and housing for cracks, worn or damaged bores, damaged threads, or any other damage that could affect operation of the transmission. Inspect the machined mating surfaces for burrs, nicks or damage.
2. Inspect the front face of case for small nicks or burrs that could cause misalignment of transmission with flywheel housing. Remove all small nicks or burrs with a fine stone.
3. Inspect bell housing for cracks Make sure the machined mating surfaces are free from burrs, nicks, or any other damage.
4. Check the condition of shift levers, forks, shift rails and shafts.
5. Inspect ball bearings. Refer to Bail Bearing Inspection.
Ball Bearing Inspection
Bearing Raceways
1. Inner Ring Raceway-While holding outer ring stationary, rotate inner ring at least three revolutions Examine raceway of inner ring for pits or Spalling. If pits or spalling are unacceptable. replace the bearing assembly. Light particle indentation is acceptable.
2. Outer Ring Raceway-While holding inner ring stationary, rotate outer ring at least three revolutions. Examine raceway of the outer ring from the same side as the raceway of the inner ring. if raceway is spelled or pitted, similar to that shown, replace the bearing assembly. Light particle indentation is acceptable.
Bearing External Surfaces
The bearing must be replaced if damage is found in any of the following areas:
1. Radial cracks on front and rear faces of outer or inner rings.
2. Cracks on outside diameter or outer ring (particularly around snap ring groove).
3. Deformation or cracks in ball cage (particularly around rivets).
Spin Test
1. Lubricate bearing raceways with a slight amount of clean oil. Turn the bearing back and forth slowly until raceways and balls are coated with oil.
2. Hold bearing by inner ring in a vertical position. Vertical movement between the inner and outer rings is acceptable. Spin outer ring several times by hand (do not use an air hose). If roughness or vibration is noticeable or the outer ring stops abruptly, the bearing should be cleaned again and lubricated. Roughness in a bearing is usually caused by foreign particles in the bearing which comes from inside the transmission case. If bearing is still rough after cleaning and relubricating three times, it must be replaced.
3. Hold bearing by the inner ring in a horizontal position with the snap ring groove up. Spin outer ring several times by hand (do not use an air hose). If bearing is still rough alter cleaning and re-lubricating three times (if not done in step 2) it must be replaced. If bearing passes the visual inspection and spin tests it can be re-installed in transmission.
Gear Inspection
Inspect the teeth of each gear. If excessively worn, broken or chipped, replace the gear. Excessive wear increases backlash, which results in noise and unacceptable operating characteristics.
Output Shaft Inspection
1. Check output shalt for run-out by mounting he shaft between V-blocks and applying dial indicator TOOL-4201-C or equivalent to several places along shaft. The standard reading of the indicator for run-out should be less than 0.05mm (0.002 inch). If run-out exceeds 0.O5mm (0.002 inch), replace mainshaft.
2. Replace input shaft if splines are damaged If needle bearing surface in bore of bearing is worn or rough, or if cone surface is damaged, replace shaft.
Countershaft Inspection
Check countershaft gear teeth and countershaft splines for wear or damage. Replace countershaft if bent, scored, or worn.
Synchronizer Mechanism Inspection
1. Inspect gear teeth on synchronizer ring. If there is evidence of chipping or excessively worn teeth, replace with new parts.
2. Inspect synchronizer ring for wear. To check the wear of synchronizer ring, fit synchronizer ring evenly to gear cone. Measure clearance between side faces of synchronizer ring and gear with a feeler gauge. If clearance is less than 0.8mm (0.031 inch), replace synchronizer ring or gear.
NOTE: First/second, third/fourth and fifth/reverse synchronizer-to-gear clearance specifications are the same.
3. Inspect contact between inner surface of synchronizer ring and cone surface of gear. To inspect, apply a thin coat of Prussian Blue or equivalent on cone surface of gear and fit it into the ring. If the contact pattern is poor, correct this by applying compound and lapping surfaces together.
4. Make sure clutch sleeve slides easily onto clutch hub.
5. Check synchronizer inserts (keys), inner surface of clutch sleeve, and insert groove on clutch hub for wear.
6. Check synchronizer insert spring for tension.
Shift Fork/Clutch Hub Sleeve Inspection
Check the contact surfaces of the shift fork and clutch hub sleeve for evidence of wear or damage. Measure from shift fork to the clutch hub sleeve. Clearance should not exceed 0.8mm (0.031 inch).
Clutch Hub Inspection
1. Check operation of clutch hub sleeve installed onto hub
2. Position clutch hub and sleeve horizontally. Lift the hub approximately three-quarters of the way off the sleeve. Release the hub, and observe downward motion. Hub should slide downward Into sleeve on its own. It should not be necessary to push hub into sleeve. Service as necessary.
Extension Housing Inspection
Inspect the extension housing for cracks. Ensure that the machined mating surfaces are free from burrs, nicks, or any other damage. if necessary, replace the oil seal after the extension housing has been installed onto the transmission.
NOTE: The extension housing rear bushing cannot be serviced. if it requires service, the extension housing must be replaced as a unit.
Speedometer Gears inspection
Check the drive gear and driven gear, and the driven gear shaft for wear or damage. Check the O-ring and oil seal for weakness, wear or damage.