Please Help!! new (used) car problem

ok so here is the deal, i just got a '92 gran marquis free from my aunt! awsome except that she says the tranny is shot, and i will need a new one. i have no idea if that is true but when i accelerate it only goes to 40mph then tops out. it just wont shift into any other gears. so after i hit 40 it just starts redlining (per say) and revving up. this started a while ago when i started to lose the normal pickup, and now no shift. does this mean i need a new tranny? or could it be something else? (it is an automatic, i dunno if they come in manual but if they do i should say it right?) also i was thinking that if it is the tranny i could sell my 97 saturn (i hate it) to pay for the repairs. is the 92 mercury gran marquis know to be a good reliable car? i really appreciate your time and responce!! thanks!

how many miles, how has it been maintained... etc.

maintaind very well, only 68k miles

maintaind very well, only 68k miles

you guys all suck!!!

Hey, sorry I was away for the holidays.

Yes, the MGM is a very reliable vehicle. Since it's not shifting you will need some transmission work of some kind.

First off, I wouldn't continue redlining it, you'll only cause more problems with the vehicle.

Ok to the trans.
I had an 86, and did a fluid change and installed a shift kit. This solved my shifting problems. You may be able to do the same, but in your situation I'd go ahead and sell the Saturn, have your trans rebuilt then you should be good to go for at least 150K miles.