Success with first attempt at 722.9 7G-tronic 7-speed automatic transmission service
#26
If only I'd seen this prior to attempting this. Used option 3 with a flex head on the extension and as you predicted, was able to strip my TC bolt quite effortlessly. I may go back under and see if I can hammer a 5mm of option 1 or 2 in it to get it out, but if not, I'll just shorten the interval and leave well enough alone.
1) If the fluid is icky, you are better off changing it gradually, with two consecutive partial changes. The sudden influx of new oil can dislodge contaminants, triggering collapse. Or so I am told.
2) If the fluid is not icky, what's the rush? Just change half of it by dropping the pan and refilling.
Every knowledgeable tranny guy I've listened to has said to just drop the pan every 30k miles, change the filter, and that's it. Nobody ever says there is a benefit to full changes - unless, I guess, you want to change to a different fluid for some reason and the two generations of fluid are not compatible.
Partial changes do consume more fluid, but boy oh boy is the workload less.