If it is an automatic, was not sure on which type you have so I am giving you both answers, there is a problem with the torque converter or the shift solenoid or the torque converter clutch solenoid or if the damage is bad enough the clutch packs have failed.
Look at the fluid and make sure it is full. Check level while engine hot and running. It will probably be dark and burnt. That is a certainty that you need a rebuild. Make sure to take it to a transmission shop as opposed to a regular garage as they will send it out for rebuild to a transmission shop and you will end up paying more.
It takes a lot of special tools, knowledge and experience to work on automatic transmissions. They are a real tough job to rebuild correctly and adjust properly. If they are rebuilt wrong there service life will be significantly shortened. Don't take it to an AAMCO as they are overpriced by $500.00 on average.
If it is a manual transmission it souds like the hydraulic clutch system has air in it or has a failed master cylinder or slave cylinder. If you bleed the sytem and it is not leaking, either the synchros or the input shaft bearings are bad and it needs to be rebuilt. I would give you the same advice as where to take it but it is not as critical as an automatic transmission.
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Saturday, March 10th, 2012 AT 7:58 PM