BEGINNING SEPTEMBER 1, 1983 ALL THM 700-R4 TRANSMISSION WERE BUILT WITH A REVISED DESIGN SNAP RING FOR BOTH THE REACTION SUN GEAR AND LO AND REVERSE SPRING RETAINER TO CASE. (SEE FIGURE 1) WHEN DISASSEMBLING OR INSPECTING ANY THM 700-R4 TRANSMISSION, IT IS NOT NECESSARY TO REMOVE THE SNAP RING FROM THE REACTION SUN GEAR UNLESS YOU INTEND TO REPLACE IT. WHEN SERVICING ANY THM 700-R4 TRANSMISSION REACTION SUN GEAR OR LO AND REVERSE SPRING RETAINER TO CASE SNAP RING, REPLACE IT WITH PART NO. 8647337. WHEN INSTALLING THE SNAP RING, DO NOT OVER EXPAND IT.
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