Inatead of adding the Lucas Transmission Fix I added about 4 ounces of Stop Oil Leak in the ATF reservoir.
2003 Volvo S60, 2.4L Turbo with 199k. No transmission issues before adding the incorrect fluid aside from a slight stutter into 3rd. It's been doing this hat since I owned it (6 years).
No known transmission fluid changes before I bought it. How screwed am I?

 

if you are concerned about adding gunk to the transmission, you should simple do a drain and fill with the correct fluid and see if that changes anything. Did you check the color and smell of the fluid before the additive?

 

The color is not deep red and smells not so fresh. I don't know if a service has been performed before i
bought it with 115k. I've had mixed responses on performing a transmission service from people, especially with 199k on it now--if it wasn't done before don't do it now they say. Catch 22 now. Do it because 4 ounces of Stop Oil Leak is in it or do it because of the color and smell, ignoring the high mileage. Or both.