Originally Posted by rmccomiskie

Here's my story about servicing the trans fluid in my 1996 A6 Quattro Avant.

I serviced my auto trans the other day. The car has 130K miles and I doubt that the trans fluid has ever been changed. I bought the car at 79K miles and, having met the woman who previously owned the car, it's unlikely that the trans was serviced by her.

Rather than do a complete flush and replace, I decided to do a service first, i.e. change only the fluid in the trans pan and the filter. The service versus flush theory is that the old fluid allowed deposits to build up in the trans valve body. A complete flush would add lots of new detergents that might break the deposits free and clog internal valves. My approach only replaces about one-third of the fluid which should work on the deposits more gradually. Afterwards, I'll drive the car for about 1,000 miles and then do another service. And, maybe next Spring, I'll do the full flush.

Here's the procedure. I drove the car over to my brother's shop. He has a lift. That's very handy as you'll see below. The drive over there warmed the car up fully. Up on the lift, I loosened but didn't remove the fill plug on the side of the trans pan (22mm hex head) and the drain plug on the bottom (allen plug, about 5mm I think). Make sure you can get the fill plug out before you drain the pan...just in case.

<img src="http://pictureposter.audiworld.com/56914/drain_plug.jpg">
Drain Plug

<img src="http://pictureposter.audiworld.com/56914/fill_plug.jpg">
Fill Plug

I removed the drain plug and drained the fluid into a container. The fluid smelled burnt and looked really dirty. I let it drain for quite a while to get as much as I could. Only the fluid in the pan drained out (about 2.5 quarts). The rest of the fluid remained in the trans and torque converter (another 5 quarts). When it finished draining, I replaced the drain plug and tightened it well (I don't know the torque spec).

Next, I removed the 4 nuts (about 10mm) that clamp the pan to the transmission. The nuts hold small clamps in place so the corners of the pan get even pressure. The clamps were well stuck in place so I had to work them back and forth until they dropped off. Then I wiggled the pan until it came free. Here's what you'll see.

<img src="http://pictureposter.audiworld.com/56914/filter_solenoids.jpg">
Trans Filter &amp; Shift Solenoids

The only thing I touched in there was the filter...the large plastic thing. It's held on by 3 Torx screws (I don't know the size). I loosened the screws and the filter dropped right off. I got my new filter and put the filter seal (O-ring) over the round hole on top. The seal seats in a depression machined in the valve body. Then I replaced the filter and screwed it in place. The Torx screws should be torqued to 71 inch pounds (per the Bentley CD-ROM). I could have just tightened them snug but my brother had a small torque wrench. The valve body is aluminum so I didn't want to crank them too tight.

I cleaned the inside of the trans pan with brake cleaning fluid. There was a magnet placed in the bottom of the pan. It's there to trap any metal filings floating around in the fluid. I left the magnet in the pan. I replaced the old pan gasket with the new one and fit the pan back onto the transmission. I replaced the 4 clamps and nuts and torqued them to 53 inch pounds (per the Bentley CD-ROM).

Next, I removed the fill plug from the right side of the pan. Here's where the lift is handy. The car has to be level because I had to pump fluid into the pan until it just dribbled out the fill hole. If the car wasn't level, I wouldn't get the right amount in there. I used a little plastic pump intended to pump oil into outboard motors. Got it at a marine supply store for about $8.00. Just stuck it into the trans fluid container and pumped away. Worked great.

Then I replaced the fill plug but didn't tighten it too much. The fluid I just pumped in had not filled the transmission fully. I started the engine and let it run for a while to warm up. As soon as I started the engine about 1 quart of fluid was sucked out of the pan. When the radiator fans kicked on I knew that the engine and trans were up to temperature. While it was running, I also shifted through the gears a couple of times to make sure fluid circulated everywhere.

Once up to temperature, with the engine still running, I pumped more fluid into the pan until it dribbled out. Now that the trans was completely full, I replaced the fill plug and tightened it securely. You can shut the engine off now.

I double checked my work, made sure all the bolts were tightened, gathered up all of my tools and went for a test drive.

Before I did this service, my car would make a slight chirp on the 2nd-3rd shift and when fully warm would drop into 3rd gear with a thunk. After the service, it's completely normal. No chirp, no thunk. It even seems to have more pep as though the power is being transmitted better. I'm thrilled. And the cost is significantly less than going to the stealer.

Here's my parts cost:

Transmission filter $9.44
Trans pan gasket $3.83
Trans filter seal $0.66
3 liters Pentosin ATF ($11.95 each) $35.85

TOTAL $49.78

(I ordered my parts online from <a href="www.autohausaz.com">www.autohausaz.com</a>)

That's my story about doing my own trans fluid service. It worked for me. Your mileage may vary. Now I can't wait for another 1,000 miles to roll by so I can do another service and see if it gets any better.

Bob.

Originally Posted by snowman '92 100

*updated 10.25.2011 - I ended my site hosting

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