After removing, cleaning and replacing the chain I noticed a ratcheting sound when pedaling. The chain has about 5,000 miles on it, but has always been regularly serviced. The cogs are in good shape. This is a Raleigh 3 speed, but the following question may apply to all bikes.
Is it possible the chain was put on wrong? If you think about it, a chain can be put on 4 different ways. Would it make any difference one way or another for a well used high mileage chain?
Could the ratchet sound be because the chain is a little loose on the cogs?
Thanks for your input.

Some small, even clicking-sound is normal for the S-A 3-spd. hub. This is the sound of the planetary-gears and pawls. But if this is different - it should be looked at. Are you sure you put it back together as it was? Measured the new chain to match the old one? What kind of chain did you use?

Thanks for the reply. The clicking/rachet sound is not from the hub. The chain is the original chain, cleaned and replaced. I have done this process many many times in the past without this noise. The chain probably needs to be tightened a little. It may be hanging on to the sprocket a little as it turns causing the sound.

Is your chain too tight possibly? Either that or worn chainring????

A chain with 5,000 miles on it would certainly not be hurt by replacement with a new chain.

Have you checked bottom bracket for proper tightness? Try taking the chain off, while noting which side of the chain was towards the gears, and put the opposite side of the chain on the gears. Your cogs and chain are likely all worn into eachother at this point.