Nissan Repair: 1993 Nissan Altima Hard shift into 1st gear, nissan altima, diagnostic computer

Question
I have a 93 Altima with a 4 speed Auto transmission and 103K miles, that all of a sudden started to stall out on me one day with no prior symptoms.  Then towards the end of the day in the afternoon as I headed home from work, it suddenly started shifting very hard into 1st gear and would jerk as it did so. It was almost as though the car needed to reach a high enough RPM ( as if in idle or neutral) or wasn't getting enough gas, before it finally caught up and shifted into gear.  After it was in 1st, the rest of the gears have no issue and shift normally.  There is no check engine light.  Checked the fluid levels to ensure everything was a the proper levels. I changed the spark plugs with the mfr. suggested NGK replacement plugs and it seemed to help out with the stalling/engine dying when idling.  However the hard shift into 1st and "neutralizing" ( as one mechanic called it)is still present.  The mechanic said it was more than likely mechanical and would run about $900 for an overhaul and guarantees it for 6 mos..  My concerns are that someone else has mentioned to me that there could also be some type of sensor or wire harness causing this that is malfunctioning from an electrical standpoint.  I have had good reliability with Nissan in the past thus I am just questioning if indeed this is a problem with the transmission given the mileage ( as the mechanic stated). I mean I never did any Trans. work on my prior 87 P/U and it had 237K mile when I sold it. Any ideas?  I don't plan to keep the car long term but I want to know if it is worth putting the money into it to use for another year or just sell as is and cut my losses.  Anyone else ever report anything similar?  Can Nissan ( or anyone else) put it on a diagnostic computer and tell me what is wrong?

Answer
Daniel,

Sounds like the governor on the transmission is sticking and that is causing the problem.  It will require what the mechanic is saying and for the quote you state it is a deal.  This is not a transmission I enjoy working on and if the mechanic can do the work for $900 bucks you are getting a deal.  On a 1993 the system is still a hybrid of old technology and electronic solenoids.  It is the governor is causing the high and hard shift to second.