Synthetic Oil Harms Transmission?

jbarrow8081 · Post by **jbarrow8081** » 11 Jul 2013, 21:09

Hello,

I read in an earlier post that using synthetic oil may harm the transmission in an xc90. Is that true? If so, why would it do harm to the transmission? FYI I have a 94 xc90 and recently had the oil changed and an seeing the transmission light come on.

Thanks for any insight.

Joe

Post by **precopster** » 11 Jul 2013, 22:13

Which XC90? Is it a 2.5 or T6?

They each use different transmissions.

You do mean '04 don't you?

jbarrow8081 · Post by **jbarrow8081** » 12 Jul 2013, 07:38

My apologies.....its a 2.5 '04 xc90. Thanks, Joe

Post by **precopster** » 12 Jul 2013, 08:00

As long as the synthetic fluid used is JWS-3309 compliant there's really no problem. Having said that there aren't many synthetic fluids available to suit these. Mobil 3309 is a non-synthetic fluid and was formulated specifically for these 'boxes and is repackaged and sold under many manufacturer brand names such as Volvo, Saturn and Saab by the dealers.

The AW55-50/51SN gearbox is fitted to a variety of Volvos in both FWD and AWD applications. I use Nulon Multi Vehicle Synthetic Fluid in my 2000 V70 non turbo which uses this 'box and it runs far smoother than with the dealer fluid in my opinion.

In your case I'd ask the service people exactly what they used in a very inquisitive non threatening way and post it up here. Also if they used synthetic fluid they should have done a total fluid change which is over 12 litres. Also be very weary if they used a powerflush machine.

The trans light code should be read and dealt with before any damage occurs.

Post by **stone36** » 18 Jul 2013, 08:04

And just to clarify, you are talking about synthetic transmission oil, as opposed to synthetic motor oil correct? For transmission it's the mobil above, or Toyota is the same actually, that's what I used last flush as it was more readily available (and cheaper).

VFLXC90 · Post by **VFLXC90** » 26 Mar 2014, 05:17

Seems the Toyota fluid is the fluid to go with?

Post by **precopster** » 26 Mar 2014, 15:16

Nissan make a synthetic trans fluid for these transmissions which is JWS-3309 compliant called K-matic

They put this to use in their Maximas and certain Infinitis. I haven't heard of anyone using this is a Volvo yet, probably because dealer price is higher than Toyota IV or Mobil 3309

Post by **JDS60R** » 26 Mar 2014, 15:23

Lots of Synthetic JWS3309 available in OP's area. Oreilly's, (Castrol - I think), Amsoil ( my fav) .
They do a far better job ( in my humble opinion and experience)

Post by **regent** » 26 Mar 2014, 15:42

You can source 3309 by the case (a little bit over 5 bucks a quart) here:
http://www.avlube.com/mobilatf3309.html

bguzz · Post by **bguzz** » 29 Mar 2014, 07:55

It doesn't harm the transmissions as long as it's the right grade. Synthetic is just a more refined and more stable fluid than the non-synthetic. It has more benefit in an engine where it is dealing with combustion in addition to lubricating and cooling. In a transmission it's benefit is generally related to its longevity of maintaining its correct properties compared to non-synthetic.