Gaskets or oil seals will leak if the bolts securing plates, covers, or retainers are loose. All Automotive Lift Repair Tampa Florida bolts should be tightened uniformly using a torque wrench. The bolts securing the input shaft retainer, gearshift housing cover, and retainer seals should also be tightened to the manufacturer’s specifications. If tightening the bolts doesn’t stop the leak, the transmission should be disassembled to repair the source of the leak.
Leaks around the threads of the fill plug, drain plugs, or bolts can often be sealed by coating the threads with lead-based paint. A loose gearshift retainer can also permit lubricant to escape.
All seals must be properly lubricated; otherwise, they will fail. Therefore, a small amount of seepage around a seal is normal. A seal is not considered to be leaking unless enough oil escapes to create a drip on the ground.
Leaking Seals
While the power plant is in the vehicle, you can inspect all Automotive Lift Repair Tampa Florida seals except the input shaft retainer seal. If this seal is leaking, oil will drip out through the plug hole at the bottom of the pan under the flywheel housing when the plug is removed.
If oil does leak from the flywheel housing drain plug, examine it closely. It may be engine oil leaking from the rear oil seal of the crankshaft. Engine oil has a lower viscosity than transmission oil, making it easier to distinguish the source of the leak.
An oil leak from either the engine or the transmission input shaft seals is serious, as it can damage the clutch. An oil-soaked clutch disk typically results in slipping or grabbing.
TESTING TRANSMISSIONS FOR MALFUNCTIONS
Beyond leakage issues, standard Automotive Lift Repair Tampa Florida transmissions in most trucks can develop other mechanical problems. The best method for identifying these problems is through a road test. Before conducting the road test, however, check for missing or loose bolts and ensure the oil level in the transmission case is correct. Also, examine the parking brake mechanism for proper mounting and adjustment, check all moisture seals or boots, and assess the operation of the gearshift levers.
The transmission is often incorrectly blamed for issues originating elsewhere. For example, with the engine running and the vehicle stationary, disengage the clutch and attempt to shift into first or reverse. You should be able to engage either of these gears without clashing or causing the vehicle to move.
If gears clash or the vehicle tries to move with the clutch disengaged, the issue lies with the clutch rather than the transmission.
First, check the free travel of the clutch pedal and make adjustments if necessary. Proper adjustment of the clutch is essential for the transmission to function correctly. The clutch must completely disengage whenever the pedal is fully pressed down and fully engage whenever the pedal is released.
With the transmission in neutral and the engine running while the clutch is engaged, all the constant-mesh gears within the transmission should be turning. There should be minimal gear or bearing noise.
If the Automotive Lift Repair Tampa Florida transmission is silent in neutral with the clutch engaged, try disengaging the clutch. If noise is then detected, the problem is likely with the clutch rather than the transmission. Typically, if noise occurs only when the clutch is disengaged, the issue may be with the clutch release bearing or the clutch shaft pilot bearing.
Occasionally, noises from other parts of the powertrain, such as U-joints, propeller shafts, and differentials, can sound like they originate from the transmission. Misalignment of powertrain components can produce noises that may be mistaken for transmission issues. Therefore, check all mounting bolts on the engine, transmission, and differentials before taking the vehicle for a road test. Also, inspect the propeller shafts and U-joints for any signs of wear or looseness.
Describing noises that may stem from the transmission can be challenging. A sound you perceive as a howl might be heard as a squeal by someone else. Other commonly used terms to describe gear or bearing noises include “hum,” “knock,” “grind,” “whine,” and “thump.”
Bearing noise is often characterized by a howl, whine, or squeal. The type of noise emitted by a defective bearing can vary depending on the nature of the defect and the load it supports. In any case, loud noises coming from inside the transmission indicate a problem.
Some whining or grinding noises are to be expected, especially when the vehicle is driven in first or reverse gear. The first-and-reverse sliding gear, along with its corresponding countershaft gear and reverse idler gear, are spur gears, which tend to be noisier. However, as mentioned in a previous lesson, spur gears are often used due to their cost-effectiveness and lack of thrust production.
In the second, third, and fourth-speed ranges, the transmission should operate much more quietly than in first or reverse.
Due to the variations in Automotive Lift Repair Tampa Florida transmission construction, different procedures must be followed for removal, disassembly, repair, assembly, and installation. Typically, these tasks require between 5 to 7 hours, depending on the specific procedure used. If you are unfamiliar with the vehicle, always consult the manufacturer’s manual.
Before removing the transmission from the vehicle, ensure that all dirt and road mud are cleared from the case and its components. Use a sharp tool to scratch or mark any moist oil spots or unusually heavy accumulations of oil-soaked road mud, as these can provide important clues to the location of small cracks or holes that might be missed during a visual inspection. However, do not confuse these accumulations with those resulting from leaking gaskets or oil seals, as some leakage is normal for a transmission that has been in service for some time.
Drain the lubricant from the Automotive Lift Repair Tampa Florida transmission. Some manufacturers suggest flushing the transmission before removal by filling it with a flushing oil and running the engine in neutral for several seconds. Afterward, drain the flushing oil from the transmission.
Once the Automotive Lift Repair Tampa Florida transmission case is removed, finish the external cleaning with steam-cleaning equipment or by hand brushing the case using an approved cleaning solvent.