Change transmission fluid or not?
 

My C70 has nearly 109,000 miles on it. A mechanic told me yesterday the transmission fluid is black and should be closer to a "hot pink" color, so he recommends changing it. The owners manual recommends "changing only for vehicles used for towing" - which this car is not. What are you thoughts? Thank you.

Your mechanic is absolutely C O R R E C T! Over time that oil is going to wear out. Here's a question I pose to all car owners, if your motor oil is dark, would you change it?

Nothing lasts forever. Get it changed. With the appropriate spec fluid for your trans ONLY, not universal fluid. Also, resist the suggestion, if made, that you need a "power flush". That's not how Volvo does it. Nor Honda, btw. Both caution against power flush since it might loosen crud and push it into areas where it will harm the trans.

Drain and refill, discussed in multiple threads here, is the Volvo recommendation.

My wife's '06 V70 has no Volvo recommendation for coolant change, either. So are we to believe that coolant lasts forever? It doesn't and will be replaced at 60K or 5 years (sooner if it tests marginal).

Your mechanic is looking out for you and not simply trying to transfer money from your wallet to his.

5 speed
 

What about if you have a 5 speed manual trans? Do you need to worry about changing it or checking fluid level?

Yes. Manual transmissions are also filled with oil. I don't know the interval
Volvo specifies, if any, but I wouldn't let it go beyond 60K miles in any event.
Something called "shear" occurs which decreases the lubrication properties over time. And, of course, you'll also want to drain it to remove metal shavings left over from initial machining, gear wear, etc. Its a relatively cheap job to do in most cars, so there's no good reason not to do it.