My friend has a '94 Maxima that has around 190,000 miles and the tranny's never been changed. When going WOT, engine revs really high but there is little actual forward movement or acceleration. Also, with OD on, the tranny sometimes does not shift from 3rd into 4th unless you pull off the throttle a lot (this is at normal RPM's 2.5k-4k, nothing ridiculous). Strangely, if the OD is turned off, it works fine. Anyway, it's clearly time for a new tranny. Someone quoted $1500 for a tranny rebuild. Is that too much? Is getting a used part the best route?

 

getting it rebuilt by a reputable (not cheapest) shop is the best route.
I went cheap on one of my cars and a year later I needed a new trans and case.

 

http://www.maximumtuning.net/

i guess he specializes in maximas and there are lots of guys on here that are very pleased with his work. give him a call and see if he can help you out.