Transfer and Differential oil change for RX300

You have AWD? full time all-wheel drive.
Transfer Case Description and Operation
The Borg Warner (BW) model 4481, RPO NR3 transfer case is a one-speed, full time, all wheel drive (AWD), transfer case. The transfer case provides power to both axles, through an external planetary type differential, which has two different sets of pinion gears. The planetary differential provides a 40/60 torque split, front/rear, full time. This means both axles are constantly being driven for maximum traction in all conditions.
The transfer case external type planetary differential functions the same as a typical rear axle differential. The transfer case differential pinion gears function as the spider gears, and the sun gears function as the side gears.
The following actions occur because of the planetary differential:
• If the vehicle is on a hoist, the front propeller shaft can be rotated by hand.
• The vehicle cannot be driven if one propeller shaft is removed.
• Operating the vehicle on the hoist can damage the differential pinion gears, by over-spinning.
• Operating the vehicle with one propeller shaft removed causes over-spinning of the differential pinion gears.
The BW 4481 design of the planetary differential allows the use with the Vehicle Stability Enhancement System (VSES) vehicles. The VSES takes use of the planetary differential, by applying braking to a tire that has less traction and dividing the engine torque to the other axle.
The BW 4481 case halves are high-pressure, die-cast magnesium. Ball bearings support the input shaft, the front output shaft, and the rear output shaft. The transfer case requires DEXRON®III ATF GM P/N 12378470 (Canadian P/N 10952622), which is red in color.

This system does not have an encoder motor.

Hello there,

From this page https://www.worldsbestoil.ca/product-cross-reference.php?year=1996&make=TOYOTA&model=TACOMA&engine=2.7L&vin=1



Extract.......

.Engine, 2WD, with filter - 5.4 quarts [1]

Engine, 4WD, with filter - 5.3 quarts [1]

Cooling System, Initial Fill - 9 quarts

AMSOIL Antifreeze and Engine Coolant

Automatic Transmission, A340E Initial Fill - 1.7 quarts

Automatic Transmission, A340F Initial Fill - 2.2 quarts

Automatic Transmission, A43D Initial Fill - 2.6 quarts

Automatic Transmission, Total Fill

4 speed A340F - 10.4 quarts

4 speed A340E - 7.7 quarts

4 speed A43D - 6.9 quarts

Manual Transmission, - 5.3 pints

Differential, With ADRD Front - 2.6 pints

Differential, Without ADRD Front - 2.4 pints

Differential, 2WD Without LSD Rear - 6 pints

Differential, 4WD Extra Long Rear - 4.5 pints

Differential, With LSD Rear - 6.4 pints

Differential, Standard Rear - 6 pints

Transfer Case, - 2.2 pints\'

the differential is that item that allows one shaft to move separate to the other connected shaft. That is to say the left wheel to go faster /slower than the right wheel as in going around a corner or moving on uneven ground. There is one in front wheel drive vehicles , in rear wheel drive vehicles , and if you have an All wheel drive vehicle there is another between the front wheels and the rear wheels in the transfer case /gearbox. Unless you have metal or water contamination in the unit or have used the wrong oil in the unit it is not necessary to flush out the diff. Changing the oil as you would the sump oil is sufficient ( drain out and refill).A word of caution here. There is a special oil used in limited slip differentials so make sure that you replace the drained oil with the correct oil for the diff as damage will result if you don't.

Changed the transfer case with what,a used unit?

That is something all shops do
Install a used up salvage yard piece

That's your problem

You always break yours down & repair

Vehicles: 2002 Chevrolet Trailblazer 4WD 4.2L SFI DOHC 6-cylinder

Your front 4WD Transfer case is low on Gear Oil.
On warm days, the Gear Oil expands slightly, and is less viscous, so the "Service 4WD" light stays off. On colder days/mornings the story changes.

The following paragraph has info applying to the manual differential only:
The 2002 Trailblazer (the first year Chevy made the Trailblazer) has a Front Differential using 1.11 (that's 1 and 1/9th) Quarts Gear Oil, and a Rear Differential with a capacity of 2.29 (thats 2 and 2/7ths) Quarts Gear Oil.
The Gear Oil needed is GM Part No.12345349 or GM Part No.1052931 (they're identical), also known as "GM Synchromesh"(R), which is a type of GLS (Gear Lubricant, Special), also known as "Manual Synchromesh Transmission Fluid 5W30". A synthetic version of which sells for $12.70/qt (USD) at
http://www.amsoil.com/storefront/mtf.aspx

This is not to be confused with 5W30 motor oil (which can be had for $3.00/qt (USD)).

The 2002 Trailblazer 4WD Transfer Case (NV126 Transfer Case) capacity is 0.8 Liters of GM Part No.12378508 (US), also known as "GM Auto Trak II"(R).
Note that one Quart (US) = 0.946 Liter, so 0.8 Liter = 27.06 ounces.

Red Line sells something that they say replaces both GM Synchromesh and GM Auto-Trak II for $12.14/Qt and $44.55/Gal (US) at
http://www.shopwiki.com/Red-Line-MTL-70W80-GL~4-Gear-Oil-%281-Quart%29

13 Manufacturer Recalls apply to the 2002 Chevrolet Trailblazer (model year 2002 was the first year Chevy offered the Trailblazer), and two recalls pertain to the 4WD Transfer Case. Note that one of the recalls applies to only 895 units, so your vehicle is unlikely to be affected by this Transfer Case recall.

2002 Trailblazer Recall ==========================
OCT 17, 2001 ' Recall ID# 54221

Recall Reason POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE)
Recall Date OCT 17, 2001
Model Affected TRAILBLAZER
Potential Units Affected 78004

Recall Summary
VEHICLE DESCRIPTION: SPORT UTILITY VEHICLES EQUIPPED WITH 4-WHEEL DRIVE. THE CALIBRATION OF THE TRANSFER CASE CONTROL MODULE COULD CAUSE INSUFFICIENT HIGH SPEED GEAR ENGAGEMENT.

Consequence
IF THE GEAR IS NOT ENGAGED, THE VEHICLE CAN ROLL WHEN THE TRANSMISSION IS IN "PARK" AND A CRASH COULD RESULT WITHOUT WARNING.

Remedy
DEALERS WILL UPDATE THE TRANSFER CASE CONTROL MODULE CALIBRATION TO INCREASE GEAR ENGAGEMENT. OWNER NOTIFICATION BEGAN NOVEMBER 6, 2001. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT CHEVROLET AT 1-800-222-1020 OR GMC AT 1-800-462-8782.

Notes
GENERAL MOTORS CORP. 01064/01065

2002 Trailblazer Recall ============================
SEP 05, 2001 ' Recall ID# 26006

Recall Reason POWER TRAIN:TRANSFER CASE (4-WHEEL DRIVE)
Recall Date SEP 05, 2001
Model Affected TRAILBLAZER
Potential Units Affected 895

Recall Summary
VEHICLE DESCRIPTION: SPORT UTILITY VEHICLES (4 WHEEL-DRIVE). SOME OF THESE VEHICLES WERE BUILT WITH A RANGE SHIFT COLLAR IN THE TRANSMISSION TRANSFER CASE THAT CONTAINS CRACKS.

Consequence
THIS CONDITION COULD RESULT IN A COMPLETE FRACTURE OF THE RANGE SHIFT COLLAR AND SUBSEQUENT LOSS OF VEHICLE FORWARD AND REVERSE GEARS, AND THE INABILITY TO MAINTAIN "PARK" POSITION. THIS INCREASES THE RISK OF A VEHICLE CRASH RESULTING FROM UNINTENDED MOVEMENT OF A PARKED VEHICLE.

Remedy
DEALERS WILL REPLACE THE TRANSFER CASES AND UPDATE THE CONTROL MODULE CALIBRATION. OWNER NOTIFICATION BEGAN SEPTEMBER 6, 2001. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT CHEVROLET AT 1-800-222-1020 OR GMC AT 1-800-462-8782.

Notes
GENERAL MOTORS CORP. 01061


Read about all (13) 2002 Chevy Trailblazer recalls at:
http://www.internetautoguide.com/10-12-2002-16-1287/2002-chevrolet-trailblazer-recalls.html

On the full size, the front actuator is electric, not vacuum.

When in 4wd mode, a switch on top of the transfer case conducts 12 volts out to the actuator. Wire #50 (brown) is the 12v feed, and it conducts to the light blue wire (#900) to the actuator.
When shifted out of 4wd, the switch opens up and no voltage goes to the actuator.

Check voltage at the connector for the front actuator (at the front differential - it looks like a large bullet that threads into the front diff.) If it has 12 volts, the actuator is the problem. If it does not have 12 volts, check the transfer case switch and the power feed to the transfer case.

I'll assume it is the actuator, if the plug to the actuator is getting 12 volts when in 4wd.
The way this actuator works, is it is a sealed chamber that gets heated by voltage. When it heats, the pin in the end swells and pushes a shift fork in the front differential. The shift fork engages a spline on the passenger side of the differential, and boom! you have 4WD.

GM offered an upgrade to this actuator that is a motor instead of a heated device. However, it requires a small harness addition, a spacer, and a new actuator. It is about a $150 to $200 option.

If I were you, I would buy a new heated actuator. They are available at most auto parts stores, and are about $90. They are also on eBay for about $55 plus shipping. These are very easy to change - just thread out the old one, and thread in a new one.

Good luck, That actuator is usually the problem 90% of time.

Unless I am mistaken and your Lexus dealer can tell you all you have to do is call them but the differential and transfer oils should be synthetic and as such never need to be changed

do you have a posi rear differinal .if so maybe the clutch pack is slipping and if thats it try replacing the oil with a clutch pack oil used on posi rear ends

Engine oil 10W30
Transmission Mercon
Front Differential 75W90
Rear Differential 80W90 (if changing I would recommend going to 75W140 sythethic)
Transfer Case: Mercon
Brake fluid DOT 3 or 4
Coolant: Regular Green