Pilot2

is250-transmision.pdfI had Blackstone Labs perform an analysis on the 155,000 mile WS transmission oil in my "new" 2007 is250; the results are below. In short, the Toyota WS fluid, even after 155,000 miles, was still performing its job. The "universal averages" that Blackstone has for this transmission was with 58,200 miles. when you compare those numbers to the 155,000 mile oil, the wear metals were approximately 3-times higher thus demonstrating that even if the WS transmission oil had been changed, the wear metals would have been about the same. Impressive. As the transmission appears to be operating/shifting perfectly and the WS oil analysis produced no "off the charts" wear metal analysis, I will go ahead and do multiple drain/fills to freshen the WS transmission fluid. is250-transmision.pdf

Just bought a 2007 is250 with 155k miles. Transmission shifts very smoothly. I do not know if the fluid was previously changed. Having heard stories of problems developing with trans fluid changes in high mileage cars, is it likely safe to change?