Sonnax has designed .010" thick rear endplay shim 77406-10 to allow adjustment to the total and top unit endplay in GM TH350, TH350C and 4L60 (700-R4)/4L60-E series applications. This selective shim installs between the rear reaction carrier support and the case bearing. The total unit endplay (tested by dial indicator on the input shaft) should not exceed .036" (.005" to .036").