Bought a used 2011 M6 with 4cyl. with 140K miles. Owner had records for frequent oil changes but nothing for transmission service. Most likely because she followed owners manual for maintenance which doesn't show anything for transmission...but thats another debate!
Vehicle's high mileage is due to frequent highway trips 125 miles each way almost daily. I've had several mechanics give differing views on whether to flush or to drain/fill or even one Mazda dealer who said leave it alone with that high of mileage. Many of the more reputable shops will not flush, only drain/fill. Looking to see if there is consensus here from knowledgeable folks. My inclination is to drain/fill, then repeat early after a few 1000 miles. With 140K on it the fluid is dirty. So whats the best method to get it in good shape?
Vehicle's high mileage is due to frequent highway trips 125 miles each way almost daily. I've had several mechanics give differing views on whether to flush or to drain/fill or even one Mazda dealer who said leave it alone with that high of mileage. Many of the more reputable shops will not flush, only drain/fill. Looking to see if there is consensus here from knowledgeable folks. My inclination is to drain/fill, then repeat early after a few 1000 miles. With 140K on it the fluid is dirty. So whats the best method to get it in good shape?