'71 Dart Custom
Advocate of the Slant
Hey Everyone,
I'm sure if I searched long enough I would find the answer to my problem in an old thread, but I'm way past my bedtime and really need to get my car back on the road ASAP.
As my user name implies, I have a '71 Dart Custom, 225 /6. The other day, I noticed that it was shifting hard when going from 1st to 2nd gear. Never did that before in the 5 years I've owned the car. It only did it when the car was cold. Once it warmed up it seemed to shift pretty much like normal.
A few days later, I drove the car again to a friend's house and it did the same thing, shifted hard into second. On the way home that night the car wouldn't shift into 3rd at all. I limped it home in 2nd and parked it.
Next morning, I cranked it and thought, "Maybe I'll let it warm up a few minutes before I take off." so I went back in the house for 10 minutes or so to give the car time to warm up. When I came back outside, the engine was dead. I tried to crank it and noticed it had a BAD vacuum leak. Hard to crank and keep running, but I managed to get it going and took it down the road. It's still not shifting normally, but it did go into 3rd. I mentioned the problem to my dad and he reminded me that those old transmissions know when to shift due to the amount of vacuum. If that's the case, what should I do? Replace the modulator valve?
I'm a decent shade tree mechanic, but I confess I know very little about transmissions. I appreciate any advice y'all might have in this matter.
I'm sure if I searched long enough I would find the answer to my problem in an old thread, but I'm way past my bedtime and really need to get my car back on the road ASAP.
As my user name implies, I have a '71 Dart Custom, 225 /6. The other day, I noticed that it was shifting hard when going from 1st to 2nd gear. Never did that before in the 5 years I've owned the car. It only did it when the car was cold. Once it warmed up it seemed to shift pretty much like normal.
A few days later, I drove the car again to a friend's house and it did the same thing, shifted hard into second. On the way home that night the car wouldn't shift into 3rd at all. I limped it home in 2nd and parked it.
Next morning, I cranked it and thought, "Maybe I'll let it warm up a few minutes before I take off." so I went back in the house for 10 minutes or so to give the car time to warm up. When I came back outside, the engine was dead. I tried to crank it and noticed it had a BAD vacuum leak. Hard to crank and keep running, but I managed to get it going and took it down the road. It's still not shifting normally, but it did go into 3rd. I mentioned the problem to my dad and he reminded me that those old transmissions know when to shift due to the amount of vacuum. If that's the case, what should I do? Replace the modulator valve?
I'm a decent shade tree mechanic, but I confess I know very little about transmissions. I appreciate any advice y'all might have in this matter.