Change it!
These instructions are pretty complete. I got them over at j-body.org.
quote:
Since it is a sealed transaxle, there is not a dipstick to check the fluid level. This makes checking the fluid a slightly involved process. It should only be necessary if there is a suspected problem related to fluid level, or to set the fluid level after a fluid change.
Instead of a dipstick, there is a “check bolt” located on the side of the case that is removed to check the level. This bolt can be found on the side that is facing the engine, just below and towards the front of the car from where the passenger-side axle shaft is connected. It is a solitary bolt, not in any pattern with other bolts. You will need an 11mm open end wrench to remove the bolt.
Where you would normally find a dipstick on a FWD transaxle, you will find a filler cap that also serves as a vent. This is where fluid is added, if needed. The cap can be found by looking directly below the brake master cylinder. It is red plastic (or was when it was new) and has a small rubber vacuum hose attached in the center of it (the vent). Remove the hose by grasping it firmly near the cap and pull straight up. Set the hose end aside, and unscrew the cap in a counter-clockwise direction, approx. 3 turns. Lift it away. When reinstalling, don’t forget to reattach the vent hose. Both the cap and the hose should be in place when checking the fluid level.
There are 2 critical components to getting a correct level reading –
1) The vehicle must be level. Since you must be under the car to remove it, this means either having your car on a hoist, or having the rear axle sitting on jackstands set at the same height as the ones holding up the front.
2) The fluid must be within a specific temperature range. At least 104 degrees F, but not yet at full operating temperature. This can be achieved by letting the engine idle for 3-5 minutes. Over 8-10 minutes, and it’s gotten too hot.
In preparation for checking the level, have a drain pan under the car and a few rags handy to clean up any spills. Using your 11mm wrench, unscrew the bolt a couple turns to loosen it up. Now you can turn it by hand to remove when you do the actual check.
The following steps outline the entire fluid level check process.
• Place the car on a hoist or place both front and rear on jackstands, keeping the car level.
• Start the car and let it idle for 3-5 minutes.
• Leaving the engine running, remove the check bolt.
• If fluid exits the hole where the bolt was, but just barely dribbles out, replace the bolt and know that your fluid level is correct.
• If more than a dribble comes out, the transaxle was overfull. When it stops draining, replace the bolt. Your fluid level is now set correctly.
• If no fluid comes out, you might be low. Remove the vent hose and the cap. Using a long-necked funnel, add fluid in .5 quart increments until it starts to drain from the check bolt hole. This process must be done rather quickly, or else the fluid will exceed the temperature range and you must start the process over.
• After setting the fluid level, replace the bolt.
Changing the fluid and filter:
There is some controversy over when the required interval is to change the fluid in this transaxle. It will vary depending on what piece of literature from GM you look at. 100,000 miles is stated in at least some owner’s manuals, while 60,000 miles is shown in others, including many of the “maintenance schedules” that GM puts out. Using a “severe conditions” schedule then halves those recommendation, meaning 30,000 or 50,000 miles.
This author’s opinion is that sooner is better. Heat is the #1 killer of automatic transmissions, and older fluid does not cool as well after it begins to break down. Using a synthetic fluid such as Mobil 1, Red Line, or Royal Purple can extend the service life. Adding an aftermarket transmission cooler will also help considerably.
There is no drain bolt on the transmission pan like there is on the oil pan for the engine. This means that draining the fluid requires removal of the pan with the fluid still in it. Be aware that this can be, and usually is, a very messy process. Particularly if this is your first time doing it. In addition to a drain pan (that can hold at least 10 quarts) it would be advisable to place a large, flat piece of cardboard under the car so that fluid does not make a mess of your garage floor or parking area.
The tools and supplies needed for this service are:
Transaxle pan gasket and filter set; Fram part # FT1166 or equivalent
10 quarts Dexron III ATF fluid (may not need all 10, see actual procedure)
Jack and 4 jackstands (or a hoist) (or pair of ramps and 2 jackstands)
Drain pan w/ minimum capacity of 10 quarts
1 can aerosol spray brake parts cleaner
Rags – preferably the lint-free variety. You’ll need a few of these.
RTV silicone gasket maker (preferably black, but blue will work also)
Ratchet and short extension bar
8mm socket
Torque wrench w/ in. lbs. indicator
Flat blade screwdriver (thin tip preferred)
Before beginning the service, the car should be driven for approx 15 miles. A combination of city and highway driving is best. This gets the fluid hot and ensures that as much as possible will be drained out. This also requires you to work somewhat fast when draining, so have your work area prepared ahead of time and be ready to lift the car quickly. It might also be a good idea to run the car for several minutes after raising it. That is not to be a replacement for the aforementioned drive, however. It should also be said that running the car while in the air should only be done after the car is securely raised and stable. Safety First!
After the drive to heat the fluid, put the car on a hoist or on jackstands. The entire car must be raised, as you want it level. Not only is it required for setting the fluid level afterwards, but it will make draining the fluid easier. An alternative to using 4 jackstands is to use a pair of ramps and 2 jackstands. This is the method I use as it allows me to “raise” half the car rather quickly. Driving the front end up the ramps, then using a jack in the center of the rear axle to raise the back the same height. A pair of jackstands under the frame rails or on each side of the rear axle to stabilize it.
To complete the service after raising the car –
1) Use a rag to wipe away dirt/grime/grease that’s accumulated on the pan. Particularly around the edge and along the bolt pattern.
2) Using the ratchet, extension and 8mm socket, loosen and remove bolts that are not in a “corner” position. There are 12 bolts total. There should be 5 bolts left after this step.
3) Position the drain pan under the car, ready to catch fluid from one end of the pan.
4) At that end (where you want fluid to drain from), loosen the 2 bolts 3-5 turns.
5) Loosen the other 3 remaining bolts 2-3 turns
6) Loosen the first 2 bolts an additional 3 turns
7) Fluid should now be flowing from the edge of the pan. If it’s not because the pan is still stuck to the case, you will have to gently pry it away with the screwdriver. This should not require much force. Be ready for the pan to drop suddenly and possible fluid splash. Remember, the fluid is hot. Be careful.
8) Once the flow of fluid has slowed, continue to loosen the bolts a couple turns at a time, lowering one end before the other.
9) When most of the fluid has drained, remove the 2 bolts from the lowest end of the pan and continue to loosen the others until the pan is completely empty and off of the transaxle. The gasket should come off with the pan. Pour out any remaining fluid and set the pan and 12 bolts aside to be cleaned.
(You should be able to hold and balance the pan in position with one hand while removing the last couple of bolts with the other)
10) Remove the filter (black plastic housing) by grasping it with both hands and wiggling it free. It is held at a single point and should come free with some twisting. Be aware that it is also full of fluid. Drain it into the drain pan then discard the filter.
11) Examine the new filter. It should be sealed in a plastic bag and either with it, or on it, will be a metal+rubber O-ring “retainer” or Seal. This is where the “neck” of the filter housing fits into and is held onto the bottom of the transaxle. Before installing, however, the old one must be removed. When removing the old filter, the old seal remains on the transaxle.
12) Do not be tempted to skip the next steps and re-use the old seal. A new filter (or even the old one) will not be sealed correctly. The sealing occurs during installation. Using an old seal could cause the filter to come loose and fall to the bottom of the pan.
13) Remove the old seal by prying it away from the opening with a thin, flat head screwdriver. Work slowly and carefully, so you don’t scratch or damage the surface inside the transaxle. It can be a frustrating step, especially the first time. Work the tip of the screwdriver under the metal edge of the old seal. Gently twist the screwdriver then repeat for the opposite side. Work your way around the edge of the seal in this manner until it comes free. Discard the old seal.
(The first time I did this step, I used a small pair of locking needle-nose pliers. It worked and I got the seal removed, but I have since found the screwdriver method to work better, and less chance of damaging the soft aluminum inside the tranny)
14) Now it is time to clean the pan. Pull the old gasket away from the edge and discard. Aerosol spray brake cleaner is the preferred solvent for this step. It will not damage the pan but will clean it and dry with no residue. That is critical. Most other solvents do not evaporate cleanly. It is best to perform this next step over a bucket or suitable container to catch the solvent. And of course, always use environmentally friendly disposal practices of chemicals.
15) Spray the entire inside of the pan with brake cleaner. Start at one end of the pan and work your way to the other, spraying away old fluid, dirt, etc.. You may have to repeat this a couple times to get it completely clean. Also make sure that the edge where the gasket goes is clean, free of any old gasket material or sealant. Do not give in to the temptation to wipe the pan with a rag. Even lint free rags can leave traces of dirt and you want the pan to be spotless. The brake cleaner will evaporate and you’ll be left with a clean, dry surface. Also note that there is a small, black square affixed to the inside of the pan. This is the “magnet” for dirt and particles. You should see black dirt wash away as it’s sprayed with solvent. Continue to spray it until the solvent comes away clean. Once the pan and magnet is clean, set it aside to dry completely. I like to turn it upside down on a clean piece of plastic, so that no dust or dirt can land in it. I let it dry as I install the new filter.
16) It would also be a good idea to spray the 12 pan bolts with brake cleaner. Once they are clean, set them under the car on a clean rag or piece of plastic, ready to be reinstalled.
17) If they came separated, assemble the new filter and retainer. Your hands should be clean and dry while handling the new parts. The metal lip of the retainer should be on the side closest to the filter body. It is not necessary to push it all the way on, as it will become fully seated during installation.
18) Position the new filter and seal under the transaxle and push it in place until stays on it’s own. Note that the edge of the new retainer is not yet fully seated against the housing.
19) Using something that is both clean and firm (clean rubber mallet, palm of your hand), strike the filter housing directly under the point where the seal is. Your goal at this step is to fully seat the seal flush against the housing. It will generally take 3-5 strikes to completely install.
20) Remove the new gasket from the box it came in. Most likely it will be cork, and twisted or wadded up. Carefully straighten it out and position it on the edge of the pan. It should be noted that while RTV silicone isn’t required for sealing, it is extremely useful in holding the gasket in place as you install the pan. For this reason, most installers use it. A full bead isn’t required. Merely a few dabs in several strategic locations along the lip of the pan. Press the gasket into place making sure to align all of the bolt holes.
21) Position the pan into place under the transaxle and start a couple of the bolts to hold it in place. Make sure that all bolt holes are lining up and that the gasket doesn’t slide out of place during the install. Starting with the “5 corner bolts”, install and hand tighten all 12 pan bolts.
22) Using the torque wrench, extension and 8mm socket, begin tightening the bolts in a criss-cross pattern. The torque specification is 10 in. lbs.
23) Remove the vent hose and cap on top of the transaxle and insert a long-necked funnel into the opening.
24) Slowly pour the ATF fluid through the funnel. After the first 4 quarts, check underneath to ensure there are no obvious leaks. If there are, either bolts are loose, or the gasket is out of position or damaged. Fix as needed. Then continue to add fluid…..
How much fluid to add?
It’s a guessing game. Here are the specs, per GM Powertrain:
Pan removal = 7.4 quarts
Complete Overhaul = 10.4 quarts.
Filter removal (and the fluid it retains) is not included in “pan removal”. Add to that, the variables of the subsequent dripping while the pan is off, and the temperature the fluid was at when drained (hotter = more) and you are left with something in between the above 2 numbers.
When I changed the fluid prior to having an additional trans fluid cooler, it took approx. 9 quarts to fill it up. After the cooler install, it takes approx. 9.5 quarts to fill it up. As of this writing, I have changed the fluid on these transaxles over 10 times and those amounts are fairly consistent. It is possible yours will take less, though. Always perform the fluid level set process described earlier.
25) Add 9 – 9.5 quarts and then set the level. Letting excess drain off, or adding in .5 quart increments until full.
26) The car may now be lowered and taken for a test drive. I like to drive for a couple miles then check for leaks while the engine is running. Assuming none are found, I then continue driving for a total of 10-15 miles before again checking for leaks both with the engine running and after shutdown.
27) If leaks are present, diagnose and fix as needed. Otherwise, enjoy the peace of mind that a freshly serviced transmission gives.
