I have a 98 v70 AWD with 186K miles. It's running well and really has no issues. I am considering having a transmission flush/fluid replacement done on it. I had one done soon after I bough the car, at about 75000 miles, about 8 years ago. I asked the service department at the local Volvo dealership what they recommend, and the (surprising) answer they gave me suggested that a flush might "loosen things up" to the point that the transmission might slip, and it would be best not to change it. Your thoughts?

The - slow change - has been discussed on this board. This is what was done with 740s - drain the pan every 30K.

Some folks that fully changed their fluid after a long time have suffered tranny problems.

Why not drain the pan at every oil change? That would get rid of some of the worst fluid and if you change your own oil, it would be, at least, a little convenient. You could measure the amount you drained out.

If you take it to a shop, they will screw it up if they use a flush machine. This is a task best done in your own garage.

Total time: 60 minutes (I take lots of breaks)

Buy 10-12 quarts of good ATF.

A 6 foot section of clear plastic hose

A hose clamp.

3 empty gallon jugs marked at 2 quart levels.

A long necked funnel for the tranny dipstick hole.

A pair of pliers.

Remove the air intake between the radiator and the air cleaner box to expose the dipstick hole.
Unclip the top ATF cooler hose (driver's side) by spreading the clip a little and sliding it back an inch. Pull the hose off the radiator. Don't loose the O ring.

Attach the clear hose to the cooler hose using a screw clamp. Drape the hose over the fender and into a gallon jug. Place the jug where you can see it from the driver's seat.

Turn the engine on. Watch the ATF drain into the jug. When the ATF gets to the 2 quart mark, shut off the engine. There are no shortcuts here.

Now, the hard part: pour 2 quarts of fresh ATF into the funnel - slowly - and try not to get it all over the floor! It takes a long time to pour in, so patience.

Start the engine and empty out 2 more quarts. Repeat until all of the new ATF is used up.

Re-attach every thing in the engine bay. Have a beer. Real time for the procedure is 30 minutes, plus however long you take getting the intake out of the car and putting it back on.

Simple!

Save the hose and funnel for future use.
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Keeping it running is better than buying new

Thanks Klaus! Is the old Dexron 3 still the ticket re: fluid? Thanks again!

I would use a synthetic such as Mobil 1 or Valvoline MaxLife High Mileage DEX/MERC Automatic Transmission Fluid. The latter is a bit cheaper but just as good for your car. Walmart sells both in Gallon jugs.

I just remembered a tricky point when removing the air intake at the back side of the radiator. You need to hold the plastic part that goes over the radiator against the radiator firmly so it doesn't rip out of its housing while you are pulling the intake line off. The other end at the air filter box pulls off easily, so you might want to do that end first.
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Keeping it running is better than buying new

I have been just draining and refiling every Sat until the fluid looks clean, I find it less stressful than fiddling with the cooling lines. Any negatives to that system?

Nothing wrong with dump and fill. Except that the cars has to be jacked up and your on your back with the ATF dripping all over your hand. IF you wait overnight until the fluid is cold (engine not started), you will drain more fluid. Carefully check the dipstick before and after to make sure you have the same amount.
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Keeping it running is better than buying new

Recomm putting a MAGNAFINE 3/8" filter in line in the upper ATF cooling line. The AW trannies have no filtration.
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The Family Fleet '90 745 16v; '90 745 GLE; 96 855T; 99 XC, collectively approaching 900,000mi and going strong.

There is a filter, but it is internal and cannot be accessed without dismantling the tranny.

If your Magnafine filter does pick up dirt/metal particles, it will be time to look for a new tranny. A manual flush at 50-70K intervals should keep the ATF quite clean. Of course, adding a filter makes flushing much easier when it is time to change the filter.
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Keeping it running is better than buying new

Has anyone installed an inline filter into there system? If so, How? I own a 2007 XC70 and would like to do it.
OR
Has anyone installed a remote filter kit for the transmission system?

By the way, I have often wondered, which is more important, that your fluid is between min and max when cold or when hot? I cant seem to get it up to the min /max lines for hot. but its perfect when cold. I could just top it off when hot, but pretty sure it would be to high when cold.