No reverse

Bought the car about a week ago. Beretta 92, 3.1, automatic, It had been sitting for about a year. Performed some basics, oil, oil filter, plugs, wires, gas treatment, flush radiator, transmission oil, . Worked well all week no problems. Two days ago it didn't take reverse sat there and played with the shifter and all of a sudden it worked. Today it would not go into reverse. I had to push the car back. Went about a mile down the road tested reverse a couple of times and OK. Went 1/4 of a mile and stopped and no reverse. Came home and nothing. I was told to change the transmission filter and and oil and give it a shot. WIll do that tomorrow. What else can I check? It starts only in Park and neutral, that's OK.

Need some trouble shooting 1, 2, 3's to sort of check out what I can. I hate taking it to the shop and give away my money for something that I could have checked.

Any help appreciated.

Arnaldo

Just my opinion but instead of a simple filter and fluid change you should try a total system flush as well as a new filter. You can do this yourself for around 50-60 dollars or have it done elsewhere for around 120 dollars. (Don't just get a flush either, make sure it is a flush AND new filter) Most places charge around 65 bucks for a filter change and 65 for a flush, but get both done. You may have junk floating around in there causing blockages. Then, top it of with Lucas Transmission treatment, which will help increase pressure and will also help if you have worn parts. Note: if you have a lot of wear this may be a temp fix or may not help, but is worth a try and should be done even if you were having no problems. Doing it yourself is a bit involved and requires a 2nd person to help you. Involves using your return cooling line (the top one) to change fluid after you change filter. If interested I will describe how I do it in another post. Not enough room on this one.