hey all, 2001 cherokee, 177k miles. still owe 4000 on it, (i traveled alot over the past 4 years i've owned it) but anyhow, my mechanic says he can get another tranny (used with 45k on it) will change out for about 800 total(parts and labor included) the body is in fair condition, little rust on the roof. for some reason the roof is the only place. Is this a good deal as opposed to cutting my losses and trading it in and being "upside down" on a new car, and should i bring anything up to my mechanic also about the newer tranny? any thoughts would be greatly appreciated?????  

what model is the cherokee? theres about 6 different automatics for the cherokee's

800 for the job is reasonable...  

When you say mechanic, are they tranny specialist. There might be several things that can be done to get more life out of it. I'm guessing it's a Cherokee and not a Grand Cherokee and the tranny is an AW-4.

It's easy for a tranny guy to check the pump pressures on the different ports and the solinodes that control shifting. Tranny shops will often give you a "free" test drive and diagnosis. Might be something simple.

If it's a 30RH (3spd auto) it's not so simple to diagnose without pulling things apart.