TLE MODULE

• Oil used in transmission and differential is called gear oil. It is totally different from the one used in motor engine. Gear oil is heavier than motor oil and has a very low viscosity.

  
• When gear oil leaks, it causes a very untidy appearance, very slippery and fatal when accidentally stepped-on.
• Gear oil should be maintained safe without finding its way dripping under the floor.
• Transmission and differential gear oil


  • Must be checked regularly for leaks
  • Leak can come from worn-out gasket and oil seal
  • Leak can come from loosed drain plug or its shim gasket not squarely seated properly

  
• Inadequate gear oil will tend the gears to heat up and if totally neglected friction between two metals contacting surfaces result thus giving a growling sound during operation.
• Parts that must be inspected when checking for leaks


  • Differential/Axle housing
  • Differential axle oil seal
  • Filler plug
  • Drain plug
• Procedure for checking transmission/differential for leakage


  1. Jack up the front and rear of the vehicle and place jack stand

  2. Inspect and clean the transmission and differential unit area

  3. Run the engine from 1 to 3 minutes with transmission shifted in gear position

  4. Bring transmission to NEUTRAL position and turn-off the engine

  5. Check if there is leak in the transmission and differential unit

  6. If leak is observed near the bolt area try to tighten it

  7. Clean the unit and repeat steps

  
• If leak still persists, pull down the unit for repair. Possible trouble may come from worn-out gasket, drain plug shim, front and rear oil seals.
• Gear oil


  • Lubricates all moving parts and prevent wear
  • Reduces friction and power loss
  • Protects against rust and corrosion
  • Keeps the interior clean
  • Cools the gearbox
• Gear oil additives


  • Increase the load-carrying capacity (extreme-pressure lubricant)
  • Improve viscosity, prevent channeling, improve stability and oxidation resistance, prevent foaming, prevent rust and corrosion, prevent damage to the seals
• Gear oil viscosity


  • Measure of an oil's resistance to flow
  • Low viscosity oil is thin and flows easily
  • High viscosity oil is thicker and flows more slowly
• Gear oil must withstand heavy duty operation in all driving range. Low viscosity reduces the ability of the oil to stay in place between moving engine parts.

  
• In some modern light vehicle, oil used in transmission and differential is the same as that of engine oil.
• Maintaining good internal lubrication is the key to the long life of transmission or transaxle. If the amount of oil falls below minimum levels, or if the oil becomes too dirty, problems result.
• Procedure for checking gear oil level

  1. Place the vehicle on level ground

  2. Locate the filler plug

  3. Clean the filler plug area and remove the plug

  4. Insert finger or bent rod through the filler opening and check the gear oil level

  5. Refill gear oil if necessary

  
• Procedure for refilling gear oil

  1. With filler plug removed, place a flexible tube in the filler opening

  2. Place a funnel on the other end of flexible tube

  3. Pour slowly a right amount of appropriate gear oil

  4. Check oil level, reinstall filler plug, tighten to specifications and test run for oil leak

  5. Jack-down the vehicle and test run for any unwanted noise and oil leak

  
• Checking transmission/differential for leakage

  1. Bring transmission to NEUTRAL position and turn-off the engine

  2. Inspect and clean the transmission and differential unit area

  3. Jack up the front and rear (if necessary) of the vehicle and place jack stand for safety

  4. Run the engine from 1 to 3 minutes with transmission shifted in gear position l

  5. If leak is observed near the bolt area try to tighten it with the use of appropriate wrench

  6. Check if there is leak in the transmission and differential unit
• Refill gear oil in the transmission and differential


  1. Place a flexible tube in the filler opening

  2. Place a funnel on the other end of flexible tube

  3. Pour slowly a right amount of appropriate gear oil intended for transmission/differential. Stop pouring gear oil when it overflows in the filler plug

  4. Check oil level, reinstall filler plug, tighten to specifications and test run for oil leak

  5. Jack-down the vehicle by slightly jacking it up, removing the jack stand, and slowly lifting down the vehicle

  6. Test run the vehicle for any unwanted noise and oil leak

  
• Gear oil


  Oil used in transmission and differential
• High viscosity gear oil


  Heavier than motor oil and has a very low viscosity
• Checking for leakage in transmission/differential oil


  • Visual inspection
  • Heating method
  • Hammering method

  
• Gear oil leaks


  • Broken gear teeth
  • Worn out oil seal
  • Damage drain plug
  • Damage filler plug
• Transmission/differential drain plug


  Commonly located at the bottom
• Low level gear oil in the transmission/differential


  • Can cause high friction on the contact gears/meshed gears
  • Can cause growling sound of the gears during operation

  
• Tools used in checking transmission/differential for leakage


  • Box wrench
  • Torque wrench
  • Adjustable wrench
• Steps in checking transmission/differential for leakage


  1. Bring the transmission to neutral position and off the engine

  2. Inspect and clean the transmission/differential unit

  3. Run the engine for 3 minutes

  4. Conduct visual inspection
• Gear oil


  Provides lubrication between contact faces to prevent metal-to-metal contact of the meshing gears
• Chemical additives


  Mixed with gear oil to improve its load-carrying capacity
• Viscosity


  Measure of an oil's resistance to flow
• Low-viscosity oil


  Oil that is thin and can flow easily on the surface
• High-viscosity oil


  Oil that is thicker and flows more slowly on the surface
• Using low-viscosity oil in transmission/differential that requires high-viscosity gear oil

  The gears will get damaged
• Automatic transmission


  Uses automatic transmission fluid, not 85W-90 gear oil
• Equipment used in checking and refilling transmission and differential gear oil

  • Hydraulic jack
  • Live vehicle
  • Jack stand
• Transmission/differential gear oil level check interval

  Every 7,500 - 30,000 miles

  
• Steps in checking gear oil


  1. Jack-up the vehicle

  2. Insert finger to the filler plug

  3. Clean the filler plug

  4. Refill gear oil

  
• Supplies and materials used in refilling gear oil


  • Jack stand
  • Utility rags
  • Plastic funnel
  • Flexible plastic
• Equipment used in refilling gear oil


  • Hydraulic jack
  • Live vehicle
  • Jack stand
  • Box/socket wrench
• Filler plug location in differential


  • Top of the housing
  • Center of the housing
• Tool used in refilling gear oil

  Socket wrench