92 Regal transmission downshift under braking

[gtphill]

Hey,

 

I have a 92 regal (series 1 3800) with about 55k miles on it. Prior to me it was driven by a blue hair. The tranny fluid was dealer swapped at 23k, and I did it again at 48k, refilling the recommended 6 quarts. There was probably a 5+ year gap between those two swaps.

 

So transmission shifts much better, and I get about 4 extra MPH for the same engine rpm at highway speed.

 

The problem is that the transition from neutral into drive is noticeably firmer and "clunky." Also the transition to reverse. Finally, under hard braking, there is a jolt right before coming to a complete stop.

 

Last week I had the repair shop fix a bunch of stuff (how does everyone find time to do it themselves?), and now that the computer has gone through learn mode again, the problem is more pronounced.

 

So, transmission experts, what should I have them look at for me? Is it the TCC solenoid, the vacuum accumulator, something else?

 

Your help is greatly appreciated!

[THe_DeTAiL3R]

I disconnected the vacuum line from my transmissionvacuum modulator and plugged the line to see if I could get "quicker" shifts, but all I really got was the SAME sypmtoms as you described above.

 

So, I'm putting my money on a bad vacuum modulator.

 

 

I don't think it would be the TCC cause that would have different symptoms.

[god910]

You're not going to get quicker shifts, only earlier shifts. The vac. mod. is to override the valvebody under heavy accel. I'd also look at mounts, they will make it cluck around while shifting. HTH.

[joey b]

like C-bad said, check the vacuum lines.

[91GPSTE]

I disconnected the vacuum line from my transmissionvacuum modulator and plugged the line to see if I could get "quicker" shifts, but all I really got was the SAME sypmtoms as you described above.

 

So, I'm putting my money on a bad vacuum modulator.

 

 

I don't think it would be the TCC cause that would have different symptoms.

 

First let me appologize for bringing this topic back to the top but I didn't feel like starting a new one.

 

Now, can you tell me where the vacuum modulator is located? Is it the thing in the back of the plenum with 2 vacuum lines going to it? One is from the throttle body and the other from the tranny area? I am having almost exact same problem as the original poster where I get a jerk coming to a stop. It started happening after I did my head gaskets so I am thinking something is not plugged into the right spot.

[GP1138]

I disconnected the vacuum line from my transmissionvacuum modulator and plugged the line to see if I could get "quicker" shifts, but all I really got was the SAME sypmtoms as you described above.

 

So, I'm putting my money on a bad vacuum modulator.

 

 

I don't think it would be the TCC cause that would have different symptoms.

 

First let me appologize for bringing this topic back to the top but I didn't feel like starting a new one.

 

Now, can you tell me where the vacuum modulator is located? Is it the thing in the back of the plenum with 2 vacuum lines going to it? One is from the throttle body and the other from the tranny area? I am having almost exact same problem as the original poster where I get a jerk coming to a stop. It started happening after I did my head gaskets so I am thinking something is not plugged into the right spot.

 

The transmission vacuum modulator is on the front of the transmission, it's cylindrical with a single vacuum line coming out of it, and it's pretty much directly under the airbox, pointing toward the front of the car.

[91GPSTE]

Thanks. That solved my problem. I think there was a leak in the rubber connector at the end. I replaced it and it shifts much better now.