Rear Shock Absorbers

I have a 1988 RRC 3.5 and for several weeks my rear shock absorbers have been squeaking loudly. I had all the springs and shocks replaced about 2 years with standard items. Is there anything I can do apart from replace them, if not, what would you suggest I replace them with (I want to keep the suspension standard)?
Thanks

Check that it's not just the rubbers top and bottom that are objecting to a change in the weather before you spend any money. The old trick (when you had no money or were flogging it) used to be soapy water but these days a good squirt of silicone spray might be worth a try.