My experience with a ford Taurus (1991) with 88,000 miles having a full T-Tech flush and refill was a disaster. In less than 2,000 miles the tranny seized and trashed itself out on the open road 60 miles from home. Cost me $2,300 to repair it and I traded the car just weeks later and got only $1,900 on trade in. I would have been better off to have had the car hauled to a salvage lot and sold for parts before having the tranny overhauled. I'm now an ASE Certified Master Auto Technician and my advice is to change tranny oil at the first 30,000 miles and then at 15,000 intervals thereafter. But on vehicles that have not had regular tranny oil changes..., do not change it, just take your chances. I intrinsically knew that I should not have changed the oil when I did but I rolled the dice and crapped out.