1995 transmission problem

[themrangry]

I have a 1995 LeSabre Limited with 175,000 miles on it. I backed out of the driveway the other day and put it in drive and nothing happened. It works in reverse, 1st and second but not in drive. Does anyone know if this means the transmission needs to be rebuild or could there be a simpler problem. could this be a vaccum modulator problem?

[maxwedge]

It is coming out and apart, fluid is full right.

[themrangry]

The transmission fluid level is okay and it does not have a burned smell to it. It did not show any signs that it was failing, no slipping or eratic shifting.

[gbeeley]

Originally Posted by themrangry

I have a 1995 LeSabre Limited with 175,000 miles on it. I backed out of the driveway the other day and put it in drive and nothing happened. It works in reverse, 1st and second but not in drive. Does anyone know if this means the transmission needs to be rebuild or could there be a simpler problem. could this be a vaccum modulator problem?

You might have a line pressure test done. I am not sure about the '95 tranny, but on the '91, when you manually put it into D1 or R, the system puts the line pressure at max. In other ranges, the line pressure is controlled by the vacuum modulator. I don't have info on the '95 tranny to know if it handles line pressure differently in D2 than in D3 or D4.

Do you get any noise from the tranny? If so, and it sounds like a soda can when you shake it up and then open it, you may have an issue with the filter and/or filter seal.

Otherwise, maybe the vacuum modulator or modulator valve is stuck? Just a guess.

- GB

[gbeeley]

Originally Posted by gbeeley

In other ranges, the line pressure is controlled by the vacuum modulator.

Hmm... on second thought, in some of those newer trannys the line pressure is controlled not by a vacuum modulator but by a line pressure PWM solenoid of some sort. The solenoid itself is (I think) inside the tranny but is controlled by the PCM/ECM. In either case, a line pressure test is probably in order...

If you subscribe to alldatadiy.com, it will probably give you much more info and diagnostic instructions for that solenoid and circuit.

- GB

[themrangry]

Well I took the vacuum modulator out and noticed that it had some fluid in it so I replaced it. No luck though, same problem is still there. If it is the solenoid that is inside the transmission I am don't think that I am set up to get into that kind of repair. I might just have to call it quits and part ways with this car. Unless someone has another suggestion.

[gbeeley]

Originally Posted by themrangry

If it is the solenoid that is inside the transmission

I don't know whether there is a line pressure control solenoid on that tranny... (since it has a vacuum modulator). There may just be shift solenoids and a solenoid for the torque converter.

The only other "easy" thing I could think of is if the shift cable were somehow misaligned so that it didn't go into drive until the lever was pointing to "2". But that would have caused it to shift normally 1-2-3-4 in the "2" position, which it doesn't sound like it is... (and it likely would have made "R" and "P" not line up right either)

If you have some diagrams on it, you could always check the resistance of the shift solenoids, and check to make sure the PCM/ECM isn't trying to command 3rd or 4th gear from a stop. Have you tried accelerating to 30mph with it in "2", and then putting it in "D"?

- GB