Changing the oil in an automatic transmission

[BigE]

Changing the oil in an automatic transmission
2000 Sport 4x4 automatic 37K
Manual says change transmission oil every 30K – now have 37K – so guess I should do it - is there a drain plug on the transmission and if yes, is it as simple as draining and refilling?

What about these “complete flushes” that are advertised?
I’ve done a search, but I’m not finding the “how to do it” – can someone point me in the right direction

 

[spta97]

The "oil" is typically referred to as "Transmission Fluid". It is not like changing the oil in the motor because a large amount stays in the transfer case. People who do the DIY method basically flush out most of the old stuff by pouring new fluid in and removing the same amount (or keeping track of it). Doing it this way people have reported success.

I did not want to deal with 12 quarts of used tranny fluid so I went to AAMCO for the full system flush. I could notice a difference in how much smoother it shifted and gained about 1 MPG to boot. Not to say you could not do it, but having a reputable shop do the work might be your best bet. They replaced the filter and seals as well for $129 plus tax. I don't think that 37k is too many miles to do it, but a professional shop can tell you better. I should also note that the V6 trannys seem to be more problematic than the V8s.

Oh, do a search for "tranny flush", "transmission flush", "flush", etc - you'll find a bunch of DIY threads.

 

[jayhawkexplorer]

There are two schools of thought regarding transmission fluid changes. One believes that a full flush of all 10 quarts or so is the best method. This is more difficult to do by yourself, but its definitely doable. Aldive, a member on the board, does this himself with no mess at all. Lots of people, and many mechanics as well, believe that flushing the entire tranny is bad and can lead to transmission failure. They recommend doing what's called a "pan drop." This involves only dropping the transmission pan and replacing the roughly 4-5 quarts that are in the pan (the rest of the fluid is throughout the transmission itself). Its a somewhat messy job to do yourself but not too difficult of one. At the mileage you've reached, I'd definitely get the fluid changed out. Its up to you to decide what method to go with. If you have a mechanic you know and trust, I'd ask their advice. My family's mechanic believes in the drop the pan method, so I stay away from flushing, personally. We've never had a tranny problem on any of our vehicles, so it makes sense to me.

 

[gavin]

I always drain the pan and TC myself, then add in the fresh fluid. Not sure what year they went away with the TC drain plugs though.

 

[IZwack]

because a large amount stays in the transfer case.

you mean torque converter?

 

[spta97]

you mean torque converter?

Probably - you see why I had someone else do it