Your 1992 Toyota Previa's transmission depends upon its transmission fluid in order to run smoothly. When transmission fluid gets dirty, it becomes thick and grimy, carrying a gritty texture that can create greater problems within the transmission itself. A well-maintained transmission has clear fluid that lubricates the system so that your transmission will run at its best. Approximately every 40,000 miles, the transmission fluid should be replaced. Fortunately, this is a task that the mechanically inclined Toyota owner will find relatively easy.
Run your engine for five to 10 minutes to warm the transmission fluid.
Turn your car off and engage the emergency brake as a safety precaution.
Elevate your Previa using a car jack and four jack stands at level degrees. The jack stands should be placed on the inner sides of the four tires so as to hold the entire car up, rather than a typical one-end elevation as with many other repairs and maintenance procedures.
Position your dripping pan beneath the ground at the middle front of your car, directly under the transmission. This will prevent spillage on the ground and make clean-up much easier after the fluid change.
Identify your transmission pan by going under the front end of your car and looking for the square pan-like object with bolts on every corner and side.
Loosen one corner bolt in the transmission pan at a time using your wrench. Follow the bolts clockwise, loosening each one slowly and preparing for some fluid to spill over the sides and into your dripping pan on the ground.
Lower the transmission pan after all of the bolts are unfastened. Use caution that the fluid does not spill onto you, but rather into the dripping pan that you have prepared for this purpose.
Clean the remaining fluid out of the transmission pan using your shop rag.
Replace the transmission pan by screwing the bolts back into place with your wrench.
Pour the contents of your dripping pan into your empty milk jug and screw the cap on tight for proper disposal.
Lower your Previa back to ground level by removing the jack stands and releasing the jack.
Lift the bonnet of your car and find the transmission fluid dipstick, which is clearly labelled as such.
Remove the dipstick and in its place, put a funnel in the transmission fluid opening.
Pour the first two quarts of transmission fluid into the funnel.
Engage your emergency brake before starting the engine so that the transmission fluid will warm again.
Shift your Previa's transmission gears after the car has run two to three minutes. Shifting the gears helps the new fluid to work its way through the transmission parts, providing a more accurate view of the transmission fluid level.
Put the dipstick back into the fluid opening and see if the fluid level is sufficient. You will know this by the line marked on the dipstick for the fluid's capacity. If the fluid measures at the fill line while the car is idling in neutral, your transmission fluid change is complete. If the dipstick shows that the fluid level is beneath the fill line, you will need to continue to add the last quart of fluid, a little at a time, until the fill line is reached on the dipstick.
Put your car back into the "park" gear and turn your car off once the dipstick reading is sufficiently full.