is it expensive? would it be better to take it to a mechanic
I've replaced them myself many times. The job is not hard if you're a pretty good shadetree mechanic. A Haynes or Chilton's manual can be a help if this is your first job. The cost for a rebuild transaxle is around $100 exchange. Find a friend mechanic if this is your first time. You do the job with him watching over your shoulder. If you take the car to a garage, be prepared to shell out around $250 or more for the job.
depends on how old the car is. I had a 2000 hyundai and it was like 250. its always better to take your car to a mechanic
If you have any mechanical knowlaedge isn't a hard or technical job, just time consuming. The axles pop out the trans and pop back in, the long part is getting the front suspension apart to get them out. you'll need to remove the brakes and axles out of the hubs to get them out of the trans. On re-assembly take care to guide the new axles back into the trans so you don't bent the metal ring that holds the seal. I find it almost the same cost to replace with new axles from local auto parts stores then to have then rebiult.
