Automotive Forums

Ok here is my problem, when my 300m gets to around 2500-3000 RPMs it fails to shift, check engine light was on. Took it to a mechanic and they pulled up codes 700, and 1776, however when they reset the light it ran fine for a little bit, but the light came back on again later in the day. At this point I'm still thinking it will not be so bad, thinking I would just need a new solenoid pack.

Anyway bring it into aamco today and now theyre saying the transmission needs to be rebuilt for between 16-2,000 as the car has little reverse once it heats up and that it will crap out soon if not rebuilt. I've heard bad things about them before so I'm getting a second opinion, but does anyone have thoughts on whether I'm getting ripped off or not? Also what are peoples opinions on used transmissions? Worth it or will it just cost me more in the long run?

I really appreciate any and all help/advice on this issue as I'm not that great with cars. Thanks.