| Subject: | 95 Galant Auto Tranny Problem |
| Question: |
If the fourth gear is shot, then why can I drive above 40Mph with the overdrive off? If I turn off the overdrive then I can do highway speed with no problems, except that the egine RPM is much higher because the overdrive is off. |
| Answer: | Do, Your 4th gear is your overdrive. In your car (and most auto transmissions) the overdrive is accomplished when the first 2 gears move together; making a 3rd and 4th gear. But in order for the other gears to engage with each other, a series of clutches and bands need to activiate. If the clutches and/or bands are not engaging the gears as they should, you will have no overdrive (4th gear). So, when you have your overdrive on, you may have a planetary carrier or sun gear that is simply spinning free when it should be engaging. This will prevent going above 40 while in overdrive. But with your overdrive turned off, you have different gears engaging, which is allowing you to travel above 40 mph, but your RPMs will be much higher because of the gear ratios being used by your transmission. Auto trannies are pretty complicated machines. If you don't have confidence
in my answer or what your mechanic is telling you, you should take your
car to other transmission shops and have them diagnose it. The more estimates
and diagnoses you can get, the better. You'll probably get better pricing
that way. |