.Knowing that I blabber too often here, I don't post a lot of stuff that I personally find interesting. However, I will toss this one out there for consideration. There are 7.5 liters of ATF in the transmission. Some people think it's good for life, which it is, technically. Good right up until the life of the transmission is cut short from dirty ATF. Volvo designed a counter in the TCM (transmission control module) to monitor hours vs load. After a given amount of use, a service message will pop up. I like to error on the safe side, so I just changed mine at 15K miles to get out the "break-in" junk and other generally oxidized fluid.
There are two schools of thought on what to do, easy and hard. Easy is to dump what is in the bottom of the transmission, and replace it. That will leave over half of the old ATF remaining, but diluted with new ATF (better than doing nothing). The hard way is to fork out $300+ to have the dealer "power flush" it to remove all the old. I read in Volvo documentation a way to flush it without the machine, but it looked like a plumbing monster involving magic proprietary wrenches to fit in impossibly tight areas. So I came up with this trick using a $4 vinyl tube, which does essentially the same thing.
1. This is the outlet fitting at the top of the transmission cooler. The line off to the side with the o-rings is no-pressure return line back to the transmission. I pulled the line out, and put in a piece of 9/16" vinyl tube with teflon tape wrapped around the end (for a great seal) in the hole. It fits comfortably tight when pushed in, and didn't leak a drop. I put the other end of the tube in a container.
2. Pull the plug in the bottom of the transmission. about 3.1 liters of ATF will come out. Put the plug back in, and put in 3.1 liters of new ATF (through the dipstick hole) to replace what just drained out.
3. Start the engine. The ATF hiding in the rest of the transmission, cooler lines, and cooler will start to pump out though the vinyl tube into the container, while sucking the fresh fluid into those components. About 2.2 liters will come out before bubbles start coming out, stop the engine then. Measure it with a graduated vessel (pyrex cooking thingy I thugged from my wife), and put that much new ATF back in the trasmission. You need a helper to start and stop the engine, while you carefully monitor the flow. It takes about 1 minute.
4. Repeat the engine start/stop cycle again, pumping out another 2.2 liters.
5. At this point, the bad stuff will be gone and new ATF will be running clear and clean. Measure what you just pumped out, and replace that amount with new. You will be darn close to what you had in before you started, minus maybe a few CC that was left in the tube and on the container side walls. Remove tube and put real line back in cooler.
6. Run engine until hot, and check the fluid level. Adjust to marks on the dip stick. That's it!
Some general notes on this procedure:
- If you can change your own oil, you can do this.
- The ATF I pumped out at 15K miles was a dark mahogany color. In a pint canning jar, it was completely opaque, even holding it up to look at the sun through it. It is supposed to be translucent. It smelled OK. I think my trans has been working fine, my guess is that it was full of break-in particles, which are abrasive and that's why I like to get initial lubes out.
- The drain plug has a magnet in it. Mine had a small amount (if you compiled it, it might be like a grain of rice) of black "paste" on it, that's the metalic sludge from wear. When I do my truck service, I get a table spoon of the stuff. The XC plug had no "glitter" or chunks on the magnet, like I usually expect to see coming out of a geared mechanism. That's nice.
- I ordered 8 liters of real Volvo ATF from Borton for $90, locally it was $22 per liter. I saved enough to buy the PA-300 75w/ch stereo amp, which, by the way, is really cool.
- These transmissions are just too complex to hope that a technician could ever re-build one correctly. Sorry, but that's how I see it. A "new" one (factory rebuilt) is $3200. The number one cause of transmission failure is dirty ATF. I think this is pretty cheap insurance. My next one will be at 50K, and 50K's after that.