What are the symptoms of a worn input shaft bearing?
Check end play with a dial indicator fastened to the case and the tip placed against the input shaft. If the reading is out of specifications, look for worn or misassembled parts while disassembling the transmission. Typically a thicker or thinner selective washer is installed to adjust input shaft endplay.
You’ll know when there is a problem with the input shaft bearing because you will hear strange noises coming from it. Here are the common causes of the noises: The number one reason for input shaft bearing noise is a lack of lubrication. This can happen after your input shaft bearing is old and has never been replaced before.
Bad Input Shaft Bearing Symptoms 1 Engine Noise in Neutral. When you set the gear to neutral, do you hear noises coming from the running engine? 2 Constant Gear Sounds. A defective input shaft bearing causes the gears to make constant noise. 3 Noise Goes Away When Press the Clutch pedal. 4 Gear Slippage. 5 Vibrations.
Power enters the transmission through the input shaft. The input shaft is connected to the engine via the clutch, such that when the clutch is engaged, power goes straight from the engine to the input shaft of the transmission, and the crankshaft and input shaft rotate at the same speed.
A bearing in the transmission case supports the input shaft in the case. Anytime the clutch plate turns, the input shaft gear and gears on the countershaft turn. The transmission output shaft, also called main shaft, holds the output gears and synchronisers. It connects to the drive shaft to turn the wheels of the car.
What does the input shaft bearing do? The input shaft connects to the output shaft with a set of needle bearings. These bearings allow the input shaft and the output shaft to spin at different speeds. Faulty needle bearings make noise when the clutch is engaged, the vehicle is still, and the transmission is in neutral.
Input shaft failures most often begin with a crack in the root of the splines and propagate at a 45-degree angle. The crack ini- tiates and grows through the hardened outer layer of shaft ma- terial when high torque impacts occur. These cracks are generated with a high torque spike above 4500 lb-ft.
Inside the transmission, an input shaft is connected with the engine, which turns the shaft; while an output shaft sends its spinning motion toward the vehicle’s wheels to turn them. The input shaft’s power drives a set of gears, called the countershaft gears.
Its probably the clutch throw out bearing – the big round one that attaches to the fork – change it, the pilot bearing in the fly wheel and the crank seal while you have it out. That play in the input shaft is fine.
If input shaft breaks, park will still work, If output shaft breaks, park will not hold as the parking pawl locks outputshaft.
There is no time frame with mechanical parts. It could last 5miles or 1000miles. No one really knows, it will fail once enough friction gets ahold of it.
A worn or defective input shaft bearing can cause noisy operation in neutral with the engine running. The pitch or tone of the noise changes with engine speed and a slight vibration might be felt through the shifter. This symptom can also be caused by deficient gear oil levels or quality.
