Ball Joints

Got an 84 300D turbo that has a major creak in the right front when bounced or under normal driving. I've been told this is likely to be a ball joint. Does that make sense? Is that something the average DIYer can do, is this part of normal lube?

Thanks

KY, That does seem reasonable but there are no grease fittings on that MB. You can change it but you need to rent or borrow a tool to compress the spring. Don't do it without that. It is under great pressure and it will hurt you.