How do you know if your transmission is going out?

Answer 1

• For an automatic transmission, one of the first signs is when it's slow to shift into gear after you first start it in the morning. If it takes more than a half second to a second from the time you put it in gear until you feel it engage, the transmission valve body seals are starting to leak.
• After that, a failing transmission will start to "slip" when you accelerate. That feels more like you're sliding into gear rather than the nice, crisp shift of a tight transmission. Either condition can be caused by poor or inadequate maintenance. It's important to change the automatic Transmission Fluid and filter on any vehicle with more than 70,000 miles on it, then yearly after that. If a filter becomes plugged, you'll end up with low hydraulic pressure and the transmission won't be able to shift properly.
• When you have the fluid changed, they'll almost always tell you that you have sediment in the bottom of the transmission and often they'll tell you to have it rebuilt because of that sediment. If the transmission is shifting ok (crisp shifts), don't let them rebuild it. A little TLC often helps with transmissions.
• If you're asking about a manual transmission, they're going bad when they make strange, howling noises or if the synchromesh isn't working. Synchro can be affected by a clutch that won't fully disengage, but if the clutch is ok and it's still grinding or difficult to shift, you may need new synchro rings.