Much of the time the gear motor inserts that are used to cushion the opening action of the motor are deteriorated. You can pull the motor open the case pull the gear and replace those inserts or save the work , buy a new motor on ebay for about $60. The 87-88 headlight motors are easy to fix while the early 84-86 motors can be a harder repair.
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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "