Youna. To have someone regrease the slip yoke for you would likely run an hour for labor & a few bucks for grease and two new clamps. Probably somewhere around $100 total. Done right, it should last 3-4 years of normal service. If there were grease fittings on the drive shafts, this would be a 1min maintenance procedure!! Greasing the SY is not listed in the owners manual for service intervals, so most dealers will cover this under the powertrain warranty. I beleive isuzu has issued a TSB, specifiying a new type of synthetic grease that is more of a permanent fix for this issue. The clunk itself is not harmful, or dangerous, but driving with a dry slip-yoke for many, many miles can damage the drive shaft. All in all, rodeo's are an above average truck. Not quite as "good" as a 4-runner, montero sport, or xterra, but better than a exploder, blazer or durango. You'll find that you get more for your $$ with a rodeo. Stick with 2000 or up- since you will atleast get 5yrs/60Kmi powertrain warranty. G/luck
Joel