What are the risks of doing a full flush on a 722.6 tranny with 90K miles?
 

I have read that doing a full flush on a high mileage (90K miles) tranny could damage it because of the new fluid (fluid shock). I have a C32 contaminated with Glycol and I was wondering whether I should do a complete flush or Is it better to only drop the pan and then do it again after like a year?

I have heard the same thing but dont know how true it is. I tell you what though you might as well try it because you are already f'ed with glycol in you trans.

That's what I thought as well, I'm just gonna flush the hell out of it! The good thing is it's a transmission that has been serviced in the past, last service was done in 2016 with 7 liters of fluid, filter, pan gaskets and bolts.

I wouldn't hesitate to do it. I don't subscribe to the old adage of the fluid it too old to change.