All-Trac/4WD Precautions

The center differential of the All-Trac/4WD Previa is equipped with the viscous coupling type Limited Slip Differential.
If incorrect preparations or test procedures are used. the test will not only unsuccessful, but may be dangerous as well.
Therefore, before beginning any such servicing or test, be sure to check the following items:
- Center differential lock type.
- Whether wheels should be touching ground or jacked up.
- Transmission gear position.
- Maximum testing vehicle speed.
- Maximum testing time.
Also be sure to observe the following cautions:
- Never accelerate or decelerate the vehicle suddenly.
- Observe the other cautions given for each individual test.

Before Beginning Test
This vehicle does not have a Center Differential Lock Mode or 4WD (Normal) Mode to allow only the front or rear wheel to be rotated.
The test method for this vehicle is different to that for vehicles equipped with the Center Differential Lock Mode or 4WD (Normal) Mode, so make sure you use the correct test method.





Braking Force Test. Vehicle Speed: Below 0.5 km/h or 0.3 mph
When performing low-speed type brake tester measurements, observe the following instructions.
- Position the wheels to be tested (front or rear) on the tester.
- Shift the transmission shift lever to Neutral (or N" range).
- Idle the engine, operate the brake booster and perform the test.