Tech Article #2 - Transmission Filter/Fluid change
A lot of you drive automatic transmissions. They vary from Manuals in a few different ways. Automatics allow for easier operation as far as driver awarness. Just put it in drive and go. Also, and most noticable, if you look under the car, you will see a drain pan where on a manual you would just have a drain plug. This is due to the lack of filter in the bottom.
1/4" ratchet with socket to fit the drain pan bolts,
Transmission filter kit from parts store (contains filter and gasket)
Drain pain to catch transmission fluid.
Spray adhesive helps, but not nessecary
Jack up the car to where you can reach the transmission pan easily but have room to move. Put Jackstands under the car in case the jack falls ( i can never stress this enough.) Use the 1/4" ratchet to break all the bolts free. just get the initial break, dont take them out yet. Then starting with one corner, (towards the rear, or lower side of the vehicle) take out the bolts on the corner... then start loosening the bolts leading away from there on both sides, but do not take them out. The initial plan is to drop one corner of the pan to let the fluid drain, so its easier to manage. some pans may take a little tug on the corner to break free but make sure you have enough bolts free and loose enough.. you do not want to bend the pan... most times the weight of the fluid will do it by itself. Let as much fluid drain out as you can and slowly loosen the other bolts to drop the remaining bit... once you can safely drop the pan all the way out, locate the filter up where the pan use to be.. some just pull out, (they have an o-ring or sleeve on them) some screw in and out, and some have retaining clips. use the new one for a reference if you cant see.
Crawl out from under the vehicle and find a table where you can work easily. Use a gasket scraper and remove all the previous traces of gasket material... Use a clean rag to wipe all all the excess gasket bits and grease that can cause leaks. Check the bottom of the pan, if there isn't a magnet, its a good idea to put a stick magnet (check clearance on tranny) to catch metal shavings that go through the pan.. this can lengthen the time between filter changes and help the tranny a lot. Use rubbing alcohol or brake clean to clean where the gasket was. Either rub it on, or spray but try not to get it in the pan. It will evaporate in open air, but im not sure what happens if it mixes with the fluid at the bottom of the pan. when that is clean and dry, hit the gasket area with some spray adhesive or even spray disc brake quiet if you are in a bind. Again, do NOT let this get in the pan.. use cardboard or a rag as a wall. Allow the adhesive to sit for about a minute to get tacky... Get the new gasket and make sure you have it the right way, then lay it on the pan lining up the bolt holes. It will probably be hard to pull back up so try and get it right the first time.. *note* Using this adhesive to hold the gasket to the pan is not required.. but will make your life 100% easier when trying to put the pan back up. The gasket is folded in the box and wants to curl which can be a pain. Also I have seen people use RTV or silicone to glue the gasket down. I can not endorse this because most are made from a rubberized compound that expands as it dries.. so where you have a layer of paste, it expands and becomes hard and pushes the gasket away and allows for leaks.
Now, you are ready for installation. You will want to put the filter in place and make sure it is secure. Now, holding a tranny pan and bolting it up can be daunting, but there are 3 ways to go about it. 1) hold the pan up and screw in a few bolts. 2) use studs to line the pan up and a nut to tighten it up or 3) what i have started using for heavier and larger pans... clean the pan on the outside, where the bolt heads sit and clean the bolt heads... use a dab of superglue to hold them to the pan... do this on about 4 bolts. and the slightest torque can break them free when in place. Do what works the best for you.. you dont have to rush. get all the bolts started and and down most of the way. Here is why i specified a 1/4" ratchet. tighten the bolts until they stop moving without force, and turn the ratchet another 1/8th turn. The smaller ratchet makes it harder to tighten them too much. Doing so can cause leaks or bent pan lips.
Bent pan lips are noticeable when you take the gasket off, you will see a dimple protruding upwards.. this is not good. If you over tighten them to this extent, and dont have a press to flatten it back out, use a socket just slightly larger than the bolt hole, secure the pan, and tap the dimple out. You probably won't have to do this... its just a precaution.
Now that the tranny pan is all tightened up, remove the drain pan and jackstands and lower the vehicle. Open the hood. Locate the Transmission dipstick. This is usually in the back on the passenger side. A little red handle. This dipstick is also the fill tube. Find a funnel to fit it (never known anyone that hasn't needed a funnel.) Fill the transmission to the recommended capacity that can be found in your owners manual, or your parts store can tell you. Usually its around 4 quarts. I personally recommend Lucas transmission treatment here... it helps smooth out operation and can lengthen the life of your tranny. Note that Lucas is a quart of additive, so just subtract a quart of transmission fluid if you use it. Start the car and let it run for about 2-3 minutes... You dont have the dry start problem like you do with oil changes because you still have fluid in your torque converter, lines, etc. When the car gets up to around 100,000 miles, if its never been done, I recommend getting your transmission vacumed. Its a machine that sucks all the old fluid at the same time it puts in new fluid. You have around 12 quarts total in the automatic transmission at most times. but this filter change will help you out a lot..
Wrench or Socket the size of the drain plug.
hand pump syphon hose.
Same as above for jacking the vehicle up. Locate the two plugs on the transmission, one upper, one lower. Loosen the lower drain plug just like an oil change. allow all the fluid to drain out. Notice the color of the fluid. If its red, chances are its automatic transmission fluid. (some manual transmissions use ATF, some use gear oil. Check with your manual/ parts person for type and quantity. allow all the fluid to drain out. Tighten the drain plug back up. Take off the upper plug. This will be your fill point. The problem with this setup is that you cant just pour it in.. at most auto parts stores, near the funnels, they have a length of clear hose on both ends of a pump ball. one end goes in the tranny, the other in the appropriate fluid.. pump in the correct quantity of fluid (most times it will be to the bottom of the fill plug. Replace the top plug and you are set... Lower the car and start it up and just move it through the gears.
Congratulations, you just changed your own Transmission fluid and filter.
If you have any questions or comments, just PM me or leave a reply to this message.
Last edited by Vortex; 11-24-2002 at 05:15 PM.