1988 gmc sierra automatic trans

I Drop The Tranny On My 88 Gmc And Replaced The Front Seal. Put Everything Back Together And Went For A Test Drive And Now It Will Not Go Into Overdrive. Check All Linkages And Sensors And Fluid. But Will Not Go Into Overdrive??????????? Any Help Will Be Appreciated. ALSO CHECK FUSES

I used to own a 1988 GMC 3500 Sierra with the 454 c.i. gas hog engine and three speed automatic transmission. It didn't have overdrive. Yours does?

I think they have a wired for overdrive.but can't really remember. when I changed the tranny in the 91 GM I thought I had to hook up some wires.

I used to own a 1988 GMC 3500 Sierra with the 454 c.i. gas hog engine and three speed automatic transmission. It didn't have overdrive. Yours does?


yes it has overdrive, its a 1988 sierra with a 350 auto, it has 1st,2nd,3rd, and then 4th and that is my overdrive.

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