Auto Transmission fluid

I think you might be asking two different questions. Question #1 "Can" you reuse old fluid that doesn't visually show the fluid as being degraded in its protective properties? Question #2 "Would" you reuse old fluid that doesn't appear to be contaminated? First answer. You could. But, visual inspection is really only a very minuscule part of what really going on with the protective properties. There is thermal and chemical breakdown, moisture contamination just to name a couple. The fluids are there to protect your investment. If you don't value the item you are protecting much.... Answer to #2. No I would not reuse transmission fluid on any level. Anti-freeze I have been known to reuse in a lesser vehicles. Like changing the really old out with just the old anti-freeze in my tractor. The fluids in question are not that expensive. It's not worth the risk IMO just to save a few dollars.