Gs300 Transmission Filter Change

[Deet27]

Changing the Transmission Oil Filter on my 03 GS300, The gearbox is starting to whine when in Drive and Reverse (sounds like a Power Steering Pump that is struggling like on full lock) gets quieter when gearbox oil warms up. Think the Filter might be restricted, nothing to loose by changing filter as car has done 185K Miles. (Drain and fills done at 136k,160k and 180k). Car shifts through gears fine.

Went to Lexus and was quoted £95 for a filter and the parts guy was unable to find a gasket for the Pan, I've order a Filter and a Rubber Gasket from Rockauto £22 Delivered https://www.rockauto.com/en/moreinfo.php?pk=478553&cc=1416596&jsn=9 

I was checking the service manual for Torque settings for the pan and noticed that Lexus uses a Tube of Red Silicone to seal the pan. Part no 08826-00090 (replaced by 00295-01281) @£32 Delivered from USA

How important is it that I use the Toyota Sealant or will the rubber Gasket be adequate? 

[Mihanicos]

You can use either.

You can also use the old gasket by applying a gasket sealant on top of it if it is still stuck to the pan or on both sides if it is free. Make sure that the gasket sealant you apply is compatible with the gasket material.