I really have no idea what type of transmission fluid was in my XJS V12 when I bought it, but I've lost some fluid during the process or pulling the radiator.

Now that it's about all back together I need to top off the transmission. I'd like to us Dextron IV. Any reason not to top it off with that vs. draining the entire thing and starting over?

Thanks,

John
1987 XJ-S V12, 62,000 miles

 

John,

None whatsoever.

Bear in mind that Dex3 is called for in these.

Also when you do drop the pan, and change the filter, you will only replace 4+ litres of a 13+ ltr system, so mix it does, and no issues at all.

The Synthetics now more readily available down here than the Mineral stuff, mix perfectly with whatever is in there.