Even if you use an oil extractor, I'd still want to drop the pan and replace the filter and clean the magnet.
If you have a GM tranny like a 4T65E, I put extra magnets inside the pan near the OEM one to improve wear metals pick up. One single ring magnet is too crummy to catch it all.
Remember, shift solenoids are electromagnets and will suck up ferrous wear metals, that stick inside and help cause delayed shifts, etc. Wear metals in the oil also causes valves to gall and stick in bores during a shift causing a P1811 code, etc....
Since doing this my OBDII code P1811 shift problems have reduced. I'm pulling my oil pan this week, I figured I found a few more spots to cram more magnets! Sounds lame, but magnets are expensive and no tranny filter can trap wear metals below 30 microns, most wear bits will be 10 to less the 1 micron.
Why do I bother? The root cause for my chronic P1811 code is GM design-defective ("cheap") spool valves in the valve body, I'd have rip it apart and rebuild with better parts from Sonnax.com....$$$ for the work plus a front wheel alignment....
I'll post some Pics during the week if you want.....
See ya
