1991 Buick Lesabre car only goes in 1st and reverse

Most every auto trans has a cable and linkage and if it is loose or the linkage is broken or damaged it won't work properly or not at all. Like every cable they stretch and so this could be the problem or you need to do that what I just mentioned or flush the trans and change the filter. It could be a faulty neutral safety switch as well. There is also a transmission speed sensor it could be faulty might throw off the shifting. Go to Ammoco and have them do the work. Remember cheapest things first before you do the big repairs. Thanks David Newton
zaopc@yahoo. Com

I finished installing the used transmission the 22nd of dec. When I realized it was doing the same thing as the other tranny.I drained fluid and changed the filter and fluid, I also added a pint of "Seafoam trantune" and put in a new modulator valve as well. Nothings changed. Like I said in my original posting both trannys are doing the same thing. The only thing that makes me still think the tranny itself is bad is while in drive once the car reaches a certain speed it feels like the transmission is not engaging and will stop pulling unless I pull it down into first. Is this a protective measure or is this the transmission slipping. Again thanks for the help.