From Mechanical Database
The following procedure should be performed every 30,000 miles to prevent premature transmission failure. The condition of the radiator is also important as it incorporates the transmission cooler inside of it. If the lines inside ever rust or leak, they will cause the coolant and transmission fluid to mix, contaminating the cooling system and transmission. Adding an external cooler to the transmission helps avoid this problem, while significantly increasing transmission life by reducing it's operational temperature. Heat is one of the biggest reasons for transmission failure.
- Raise the vehicle. Either drive it on ramps or jack it up and place it on jack stands. Either way, be sure to engage the e-brake before doing any work.
- Unbolt the plastic splash shield pannel that obscures some of the bolts on the bottom of the transmission. It is held on by 10mm screws and bolts.
- Place an oil drain pan beneath the transmission to prevent getting fluid on the ground.
- Remove all of the 10mm bolts that secure the transmission oil pan. A 10mm wrench or swivel sockets may be required.
- Begin to pry off the pan, lots of transmission fluid will leak out from all sides of it so it helps to have a large oil drain pan or a container of any sort there to catch it to avoid making a mess.
- While the fluid is draining, undo the 17mm front crossmember bolts, but do not remove them completely. The purpose is to back them out 1" or so, to gain some play in the crossmember. If removing the pan becomes too troublesome during the procedure, then remove the crossmember completely.
- Remove the transmission filter. The filter is secured on by two long 10mm bolts and one shorter 10mm bolt. Note that there is a rubber o-ring on the filter, the new filter that will replace it must have a rubber o-ring on it as well. They are usually supplied with filter kits.
- Remove the magnets from the pan and set them aside.
- Using a wire wheel clean the old gasket and any dirt off the lip of the pan.
- Clean the inside of the pan throughly with brake cleaner.
- Clean off the two magnets with brake cleaner.
- Place the magnets back in their proper place in the pan. Allow any brake cleaner to evaporate and make sure there is no dirt, contaminants, or metal particles in the oil pan. You do not want them circulating through your transmission.
- Apply black silicone or rtv to the edge of the pan.
- Put the gasket over the black silicone or rtv. Press firmly so that it sticks to it well.
- Clean up the surface of the transmission bolt holes with a blade.
- Apply silicone on the outside of the gasket.
- Reinstall the pan back on the transmission.
- Secure the screws in the corners to allow an even installation of the pan and allow the silicone to adhere to the transmission.
- Screw in the bolts and torque them down. Get a feel for the bolts and do not overtighten them as this can either strip the threads or ruin the gasket. If a torque wrench is available, the proper torque settings are 74-95 in-lbs (91) and 69-95 in-lbs (92-03).
- Fill with transmission fluid of choice, such as Castrol Mercon V. Avoid cheap universal fluids, as they can cause premature transmission failure. Refer to the requirements chart on the top right for average drain and refill capacities.
- Check fluid levels and verify that there are no leaks. If any leaks develop in the gasket, sometimes tightening the bolts a little more will resolve them. When checking the fluid level, make sure the transmission is at proper operating temperature. This means doing at least 10 minutes of driving to warm it up. Unlike engine oil, to check the transmission fluid the car must remain on and preferably in neutral.