No, it has a timing chain.
The Lexus GS300 qualifies as a midsize sedan. This is a great car, and it has only improved with each new generation Lexus has released. Its latest design was in 2006; however, the 2006 model was discontinued after a year and then rereleased as the GS350. Lexus made the GS350 in a response to the consumer complaints about the lack of power in the GS300. The GS350 was released with a 3.5 Liter V6 engine. Both the GS300 and the GS350 are identical except for the beefed up engine. Hope this helps.
PLIZ HELP How can i reset the injector maintenance required in lexus gs350 2012
http://www.clublexus.com/forums/showthread.php?t=338155
GS350 uses long-life transmission fluid which doesn't have to be replaced until 90,000 miles. Make sure to get it replaced at reputable Lexus dealer , since they have the equipment to flush the entire fluid, rather then just draining portion of it.
Lithium CR1632 (2008). I just replaced mine and got it from the dealer.
ubderneath the dash of the driver and passenger side. it has two switches one on each side
The following models are affected: 07-09 LS460 AND LS460L, 07-09 GS350 AND GS450H, 2008 GS460, 2008 LS600HL, 2006-2008 IS350.
Grundig/Eaton am/fm/shortwave radio in silver- model GS350
first disconnect the minus battery terminal then the positive terminal. second remove the nut on the battery support by using a 10mm wrench. remove support. you now need to get hold o a regular screwdriver and bend the end of it to 90 degrees to the shaft and make sure when you bend it that it stays parallel with the shaft. On the side of the plastic cover there is a cable clamp holding the 2 positive cables you need to use that bent screwdriver to assist you in opening the cable clamps by inserting it in the groove and help pry open the half clamps . once you have done that you then remove the plastic cover over the battery and then the battery be careful as not to tip over the battery as it contains acid and can be harmful if spilled. to install new battery just follow these steps backwards. good luck