Procedure for changing front differential fluid on a 100.
Draining:
Drive the vehicle to warm-up the gear oil. It’s best to raise the front of the vehicle to gain more working clearance. Ramps work well: http://www.autobarn.net/usm11905.html. Remove the rear splash pan, six 12mm bolts. Remove the fill plug first. It’s located on the passenger side of the differential housing. It has a 10mm Allen head (verify before starting job). Use an Allen socket on a racket to remove the fill plug. Be sure the Allen socket stays squarely in the plug head as pressure is applied to the racket handle, especially if a cheater pipe is used. Apply slow steady pressure so it doesn’t strip out. Remove the fill plug before the drain plug so in case the fill plug is frozen or stripped and won't come out you’re not faced with no gear oil in the housing and no way to refill. If the plug is frozen, spray it with PB Blaster brand penetrating oil and let it work for 15 minutes. Once the fill plug is removed, place a drain pan under the differential and remove the drain plug. It is located below the fill plug. Use the same Allen socket used on the fill plug.
Filling:
Remove the old sealing ring gaskets from the two plugs. Clean any metal particles off the magnet on the drain plug. There should only be a little finely ground metal dust (paste); no chips or chunks (i.e. broken gear teeth). Being able to see and evaluate the debris on the magnet first hand is one advantage of changing the fluid yourself. Clean both plugs with solvent and a wire brush so they look like new. Install new sealing ring gaskets. These are hollow aluminum, crush type gaskets. Don’t reuse the old ones! Coat the plug threads with anti-seize. Clean the sealing surface around the drain plug hole with a rag. Install the drain plug and torque to 35 foot-pounds. Fill the housing with new gear oil. There is not enough room to insert the nozzle of a 1 quart lube bottle into the fill hole and transfer directly from the bottle. At a minimum, a 4 foot piece of ¼” ID clear plastic tubing is needed. Force one end down over the nozzle on the lube bottle (don’t cut the nozzle back to short or the tube won’t stay on) and route the other end through the passenger side wheel well to the fill hole. Hold the tube in the fill hole and have an assistant invert and squeeze the bottle to fill the housing. As an alternative, purchase a lube pump that screws onto the lube bottle or a suction gun, either is <$10. Suction guns are sold next to grease guns, come with a 12” extension hose, and work well. Fill until lube barely runs out the fill hole. Clean the sealing surface around the fill plug hole with a rag. Install the fill plug and torque to 35 foot-pounds. Properly dispose of the old gear oil.
Materials:
2 drain plug gaskets, Toyota part no. 12157-10010 @ $.95 each from local dealer or $.69 from online discount dealer. Description: hollow aluminum crush type gasket with 18.2mm ID x 24.1mm OD x 2mm thick (prior to crushing).
1.8 quarts of SAE 80W-90 hypoid gear oil that meets or exceeds American Petroleum Institute (API) standard GL-5 (chose your own poison, e.g. petroleum based, synthetic, Redline, Amsoil, Castrol, Mobil, etc.).
Anti-seize compound
Tools:
Racket with 10mm Allen head socket (requires Allen socket to use torque wrench when installing plugs)
12mm socket and extension
Torque wrench
>1-gallon drain pan
Wire brush
4 ft. of ¼” ID clear plastic tubing or lube bottle pump or suction gun
Rags or paper towels
Disposable latex gloves (recommended)
Notes:
1. Verify plugs are 10mm Allen head; could be 24mm hex head or other size
2. Drain plug gaskets fit 10mm Allen head and 24mm hex head plugs
3. A Torx T-55 bit fits a 10mm Allen
4. If drain plugs are 24mm hex head, a racket with 15/16” six-point socket is recommended. 15/16” twelve-point or 24mm six or twelve-point should work. 15/16” six-point PTI-drive socket (relieved corners) is the safest bet because it grips the six sides, not the six corners.
5. Fill and drain plug threads are M18 x 1.5mm pitch.
6. Drain plug has magnet, fill plug does not
7. The Allen head plugs seem to be made from stronger steel than hex heads
Draining:
Drive the vehicle to warm-up the gear oil. It’s best to raise the front of the vehicle to gain more working clearance. Ramps work well: http://www.autobarn.net/usm11905.html. Remove the rear splash pan, six 12mm bolts. Remove the fill plug first. It’s located on the passenger side of the differential housing. It has a 10mm Allen head (verify before starting job). Use an Allen socket on a racket to remove the fill plug. Be sure the Allen socket stays squarely in the plug head as pressure is applied to the racket handle, especially if a cheater pipe is used. Apply slow steady pressure so it doesn’t strip out. Remove the fill plug before the drain plug so in case the fill plug is frozen or stripped and won't come out you’re not faced with no gear oil in the housing and no way to refill. If the plug is frozen, spray it with PB Blaster brand penetrating oil and let it work for 15 minutes. Once the fill plug is removed, place a drain pan under the differential and remove the drain plug. It is located below the fill plug. Use the same Allen socket used on the fill plug.
Filling:
Remove the old sealing ring gaskets from the two plugs. Clean any metal particles off the magnet on the drain plug. There should only be a little finely ground metal dust (paste); no chips or chunks (i.e. broken gear teeth). Being able to see and evaluate the debris on the magnet first hand is one advantage of changing the fluid yourself. Clean both plugs with solvent and a wire brush so they look like new. Install new sealing ring gaskets. These are hollow aluminum, crush type gaskets. Don’t reuse the old ones! Coat the plug threads with anti-seize. Clean the sealing surface around the drain plug hole with a rag. Install the drain plug and torque to 35 foot-pounds. Fill the housing with new gear oil. There is not enough room to insert the nozzle of a 1 quart lube bottle into the fill hole and transfer directly from the bottle. At a minimum, a 4 foot piece of ¼” ID clear plastic tubing is needed. Force one end down over the nozzle on the lube bottle (don’t cut the nozzle back to short or the tube won’t stay on) and route the other end through the passenger side wheel well to the fill hole. Hold the tube in the fill hole and have an assistant invert and squeeze the bottle to fill the housing. As an alternative, purchase a lube pump that screws onto the lube bottle or a suction gun, either is <$10. Suction guns are sold next to grease guns, come with a 12” extension hose, and work well. Fill until lube barely runs out the fill hole. Clean the sealing surface around the fill plug hole with a rag. Install the fill plug and torque to 35 foot-pounds. Properly dispose of the old gear oil.
Materials:
2 drain plug gaskets, Toyota part no. 12157-10010 @ $.95 each from local dealer or $.69 from online discount dealer. Description: hollow aluminum crush type gasket with 18.2mm ID x 24.1mm OD x 2mm thick (prior to crushing).
1.8 quarts of SAE 80W-90 hypoid gear oil that meets or exceeds American Petroleum Institute (API) standard GL-5 (chose your own poison, e.g. petroleum based, synthetic, Redline, Amsoil, Castrol, Mobil, etc.).
Anti-seize compound
Tools:
Racket with 10mm Allen head socket (requires Allen socket to use torque wrench when installing plugs)
12mm socket and extension
Torque wrench
>1-gallon drain pan
Wire brush
4 ft. of ¼” ID clear plastic tubing or lube bottle pump or suction gun
Rags or paper towels
Disposable latex gloves (recommended)
Notes:
1. Verify plugs are 10mm Allen head; could be 24mm hex head or other size
2. Drain plug gaskets fit 10mm Allen head and 24mm hex head plugs
3. A Torx T-55 bit fits a 10mm Allen
4. If drain plugs are 24mm hex head, a racket with 15/16” six-point socket is recommended. 15/16” twelve-point or 24mm six or twelve-point should work. 15/16” six-point PTI-drive socket (relieved corners) is the safest bet because it grips the six sides, not the six corners.
5. Fill and drain plug threads are M18 x 1.5mm pitch.
6. Drain plug has magnet, fill plug does not
7. The Allen head plugs seem to be made from stronger steel than hex heads
