I had a trans flush and a quart of additive at 30k miles. I also added a remote filter mount which runs a HP-1 filter. I added 6oz of ARx about 1500 miles ago. I haven't got all the Amsoil trans fluid yet and want to run the fluid for 5-6k miles. Should I just change the fluid filter? What interval?
If the transmission is spotless clean I would have no problem running ARX in the transmission for much longer than the 1000 miles. But the only way to verify a spotless tranny is to tear down. So in reality I advise that the stock instructions is the way to go.