I'm fairly mechanical and do most of my own work. However I have never messed with transmissions. I hate to pay a shop big money to change the fluid and filter.


How hard is it and are there any secrets I need to know when doing it?
700R4 automatic..

 

It's quite easy. Almost TOO easy in fact.

Hardest thing is, avoiding getting a trans fluid bath. A REAL BIG drain pan helps greatly with that. Needs to be about 2' square and 5" deep or so. It'll have to hold around 2 gallons of fluid without sloshing and otherwise being impossible to handle cleanly.

I'm going to assume you don't have a drain plug:

Put the car up on 4 jack stands; 2 under the axle tube, 2 under the K member or front control arm right near the CA bolts. Put your drain pan under there. Take all the pan bolts out except for 2 at the front corners and 2 at the back. Loosen those slightly. Place your drain pan under the trans pan. Loosen the 2 at the back until fluid starts seeping out pretty good; then take the front ones most of the way out. Wait for the fluid to quit dripping so much. Move the drain pan toward the front. There'll still be about a gallon and a half of fluid in the trans pan; hold it up with one hand and take the 2 front bolts the rest of the way out with the other, and let the pan down slowly. After it mostly empties out hold it back up with one hand and take out the 2 back bolts. Dump it into the drain pan as much as you can. Leave the drain pan under the trans for awhile and let the trans drip.

If you DO have a drain plug (unlikely but possible), just take it out, let it drain into the BIG pan, then remove the trans pan.

When you take out the filter, MAKE SURE the O-ring comes with it. Bad things happen if it's still in there and you put the new filter on.

Expect it to take around 8 qts or so to fill it back up. Pour in about 5; start the car; keep checking and adding until it's full.

 

Fill it through the dip stick tube I assume?

 

Yup

 

I didn't check to see if the o-ring came out with the filter one time and ended up jamming the old o ring inside its bore, caught my mistake before putting the pan on luckily. good advice as always sofa

 

To do a complete change of oil in the transmission, you will need whatever your system holds in total and add two quarts to this. Get a new filter. Use Sealed Power with the ID marks on the filter as SPX, microfelt or filtran or the Allomatic with a large "F" on top of the filter. Do not use any other as these two are the best and were at different times oem filters. After changing the filter and pan gasket, add 6 quarts to the system and disconnect the top line at the transmission. Use a large container to catch the trans oil in and be able to see the fluid coming out of the line once the engine has started. Have the rest of the containers opened ready to add. Have someone start the motor and you start adding fluid as fast as possible. Stop adding oil at the last two quarts, and watch the oil going into the container. When you see the new oil starting to go out of the transmission line, stop the engine immediately, and re-attach the transmission line and re-start the engine and check the oil level and add what is needed. It will in most cases take most all of the oil. Now you have done a 98% -99% complete transmission oil change. From what I have heard over the years about the shops having transmission flushed is nothing but nightmares. 2 to 4 weeks later and you need a transmission. This is much cheaper and you will not hurt the transmission here. For non-synthetics, Mobil, AC Delco, Aamco (Mobil repackaged) and Chevron Delo. For synthetics, regular Amsoil and Redline are the two best.

 

Great info guys, thanks!


Hey Pro, where exactly is that line located you describe disconnecting?

 

Pro Built Automatics. What about Acdelco dexron vi ? Interested in your thoughts?

 

Disconnect the top line at the transmission. AC Delco Dexron III was good, and I would think that AC Delco Dexron VI would be fine also.