Last fall my transmission lost 3rd gear, so it's time to get it fixed. My question was whether I need a shift kit. I've read about having them put in while the trans was being rebuilt, but what do they do? I'm pretty functional with maintenance basics but I know nothing about transmissions. Do I need to look for a specialty shop, or can I take it to the local AAMCO, etc.?

I can answer this.I suppose you have the orignial 700R4 Trans.82 was the first year for these trans.GM had some reliability issues with these through warrenty claims.By about 86-87 or so those had been resolved with much stronger internals.Make sure you tell your trans shop.Might not be any of the old stuff around anymore anyways.I had mine gone through and did have a shift kit put in at the time.I think it was about another $50.00.What a shift kit does is gives you a much stronger shift between gears,more like a BAM! instead of a slip into gear.Well worth the money and it does not affect the life of your trans.Any trans shop can do this.I suggest the B&M shift kit.Ask if you need anymore info.I'm not a trans expert but I did sleep at a Holiday Inn last night.LOL!!!

Thanks copter

that was me

I had mine completely rebuilt 6months ago, I had the input spline changed to the newer heavy duty unit, and my tranny shop knew all the weaknesses and changed them all out, he ground out the servo's to make them hit stronger and installed a transgo kit. It cost around 850bucks, but now it shifts like a 4speed. Oh, by the way, he also changed the overdrive(lockup) from computer controlled to hydraulic which kicks in about 50mph. (I don't use the computer anymore) so that can be done if needed. I am running 100% B&M trick shift fluid now too.
Steve

Steve,Why don't you use the computer anymore.Did you change over to a carberator?I wish my OD kicked in at 50mph.Can this be done useing the crossfire set up?