My son was driving his 02 300M 142000 mi on the hiway car was running fine.He then heard a noise the RPMs went up & the trans appeared to be slipping.He nursed it about a mi to a rest area & I had it towed home.Now if you put it in drive it will move forward but makes grinding noises wont do anything in reverse.The trans fluid is full&the fluid is not burnt at all Any ideas as to what it may be?
Thanks
Sal