2001 S80 Recommended Trans. Change for Old Unit

wildzontar · Post by **wildzontar** » 22 Oct 2013, 23:59

I've been going about 50,000 miles on the same gearbox oil (last changed at 160k) so I'm coming up on another change. I hear a lot that if I change the ATF fluid now, it will start acting up due to the age of the unit and the "friction material" draining with the old fluid. Is that true? Flud doesn't look burnt or anything now, nor is it low, and the "problematic" GM transmission has operated without incident so far.

difflock54 · Post by **difflock54** » 23 Oct 2013, 14:49

Just use JWS 3309 spec ATF, either Mobil 3309 or Toyota T-IV (which is the same but cheaper) and you'll be OK.
The Volvo supplied ATF is the same stuff. (Volvo ATF fluid is not synthetic )
Do not power flush the transmission.
Do a 'drain and fill' change which involves removal of approx 3.5 litres, then refill via dipstick tube with fresh.Run car for a period and repeat process again ,maybe a 3rd time also depending on the color after each drain.
Posts (numerous) describing this method are on the forums

Note: Dexron III can be used if your gearbox is a AW50-42LE which is a 4 speed box but not for the 5 speed box.

matt5112 · Post by **matt5112** » 23 Oct 2013, 15:14

difflock54 wrote:Just use JWS 3309 spec ATF, either Mobil 3309 or Toyota T-IV (which is the same but cheaper) and you'll be OK.
The Volvo supplied ATF is the same stuff. (Volvo ATF fluid is not synthetic )
Do not power flush the transmission.
Do a 'drain and fill' change which involves removal of approx 3.5 litres, then refill via dipstick tube with fresh.Run car for a period and repeat process again ,maybe a 3rd time also depending on the color after each drain.
Posts (numerous) describing this method are on the forums

Note: Dexron III can be used if your gearbox is a AW50-42LE which is a 4 speed box but not for the 5 speed box.

OP has already stated (s)he owns a vehicle with a GM transmission. So use Dex III, not 3309. It'll also take about 7-8 litres, not 3.5.

If the fluid is clean, and it works well, new fluid won't hurt it.

Post by **jimmy57** » 23 Oct 2013, 17:42

The risk is not from a drain a refill but from total flush. Drop pan and then refill what is lost or overfill by 4 quarts and then take the cooler line that faces rear off the gear box and put in bucket and then crank engine and let it run and pump a gallon out. Then put line back on and check and add as needed.

You can do this with no worries.

volvos80forlife · Post by **volvos80forlife** » 23 Oct 2013, 22:12

ya i am going to do the drain and fill on my 2006 S80 2.5T. it has 98,000 miles and i think flush will hurt the transmission down the road ..to a drain and fill is the way to go.

SimLyons · Post by **SimLyons** » 26 Oct 2013, 16:56

Following Jimmy's suggestion to me I dropped the trans pan (SLOWLY!! Or you will have ATF all over everything!), let it drain and drip for about 30 minutes, cleaned out the layer of whatever on the pan, cleaned and replaced the magnet, used a new gasket and put the pan back up. Then filled with 7 qts of Castrol DEX VI (synthetic blend) and a pint of Lucas Trans. conditioner.

Ran it for a while, checked the level, perfect, and drove it. Rechecked and the level (hot) was just on the full side of the hash mark. Pink and clear. My S80 is a 99 T-6 with a new transmission 60 Kmiles ago. I intend to drain and fill every 3rd oil change.