My 2003 cevy venture van has 211,000 miles on it. should I replace the axles?

Its not necessary to replace the axles due to periodic maintenance or because or your mileage. I would however check both front wheel bearings as they are known as problem areas for venture vans. Also check the CV boots at both ends of your front axle shafts. If they exhibit rips or grease can be seen leaking from them, then I would recommend replacing them. It is usually cheaper and easier to replace the entire axle, rather than have just the boots repaired. But if no obvious problems are present, there is no need to simply replace them.