1982 ChevyVanG30 Jam.23' RV NEEDS Diferental service,under hood tag says H.D.REAR END Differinchal is that limited slip? Mech shop says $200 if limited slip fluid & gasket. Is H.D. Diff. limitedslp?

One way to be absolutely sure is to jack up the rear end until both rear wheels are off the ground. Grab one wheel and turn it forward or backward. If the wheel on the other side is going in the same direction, it's limited slip. If the wheel is going in the opposite direction each time, it's not. Not hard to change oil in the rear end, not really messy either. You'll need at least a gallon of gear oil (weight and type dependent on owner's manual and limited slip), gasket and gasket sealer. Sometimes the old gear oil smells really bad, but DIY it's easily half the price quoted