Toyota Repair: 1996 previa tranny fluid issue, transmission damage, fluid transmission

Question
I have a 1996 previa LE SC with 154000 miles. I purchased it with 1459000 and immediately changed all fluids, including dropping the transmission pan and replacing the filter. Went to Toyota for fluid and was sold Type T-IV which I put in and drove for 3000 miles, then thinking it would be good to drain and re-fill due to not having flushed it I happened to read the manual which clearly states to use only Dexron fluid or serious damage WILL result. I have drained and re-filled twice now with Dexron and Toyata says no big deal, what do you say? Any help will be appreciated.

Answer
Using the T-IV fluid in a dexron fluid transmission may cause soft shift feel but in my opinion will not do serious damage to the transmission if caught early enough, however, using dexron fluid in a transmission designed to use the type-IV fluid will in most cases cause harsh shifting and other problems that can resuslt in transmission damage. I would recommend using a transmission flush machine to remove all the old fluid and fill it with the correct fluid.