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Old 04-11-2012, 05:46 PM   #1
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Received this post in visitor messages. We prefer to keep everything mechanically related in the open, so I share this with everyone

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Big Red looks great, always liked those Park Avenues..
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Thankfully my cell phone is very generous when it comes to overlooking blemishes.

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What is the story on the Adjustable Trans Modulator..?
The Adjustable Transmission Modulator is a modulator that controls the line pressures in the transmission. Higher line pressures mean firmer and quicker shifting (quicker, not sooner). Quicker shifts mean less wear per shift, which means longer life and less heat, usually at the expense of comfort. Sure, there is a happy medium. If you set it too high however, it could slam in to the next gear, and cause excessive shock to drive line components. Simply, the modulator hooks to the vacuum system to give the transmission some idea how much throttle is being used so it knows how to shift. Less vacuum, means the shift should be more aggressive as there is a lot of throttle, lots of vacuum means the shift can be more casual, as the driver is just loafing along.
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Can it be set to eliminate the "lugging" when the trans goes into OD at low speeds and the rpm seems to drop to about 200..?
In our application, the computer should not be commanding overdrive until 48mph. Quite frankly, I wish it was sooner, as there are many occasions where I would love to be loafing along at 45mph with the engine pretty much at idle. If the engine is lugging, you should start a thread in the appropriate mechanical section, and we can get right on getting it figured out for you.
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Is it a relatively simple/easy bolt-on?
Very easy. 1 bolt, the old one comes out. Put the clamp on the new one, and bolt it back in. You may need to do some rearranging with the vacuum line to get it to it, but you can figure that out.
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Where do I get one & what do they cost?
http://www.napaonline.com/Catalog/Ca...(P_RecType%3aA)
I picked mine right up at a local Napa. I remember mine being around $40, but I could be wrong. It has been on there for quite some time
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Old 04-11-2012, 05:53 PM   #2
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Just an FYI, I believe it is possible to change something in your CP to disable visitor messages. Same thing with PM'*. Its best not to PM someone with a mechanical question. Best put out in the open of the forum.

Anyhoo, thanks for putting this out in the open.
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Old 04-11-2012, 05:57 PM   #3
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It didn't bother me that it made it to visitor messages. I just brought it to the forums as is my nature and shared the response with everyone. I just document where it came from so that others don't think I am crazy when I start responding to someone that is not there
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Old 04-11-2012, 05:59 PM   #4
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Oh thats ok. I sometimes start posts just to have a conversation with myself.
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Old 04-11-2012, 06:23 PM   #5
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Excellent post, Thanks..
I'm happy to have prompted it, maybe it'll help out a number of fellow enthusiasts

You listed having an Adjustable Transmission Modulator on your car (on your sig pic), and your car is a close sibling to my car, so that'* why I asked you directly via a visitor message rather than create a thread.
Good lookin out on your part, creating a concise, informative thread on the subject.

I'll have to monitor just when my LeSabre hits OD, all I know is sometimes it sounds & feels like it'* "lugging" (turning an exceedingly low rpm for the roadspeed & terrain). Then again, I'm used to V8'* with old PowerGlides or TH350'* & 3:23 Posi rears.. So this "new" Buick is a different world lol
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Old 04-11-2012, 06:24 PM   #6
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Oh thats ok. I sometimes start posts just to have a conversation with myself.
It'* when you answer yourself that we start to worry.
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Old 04-11-2012, 06:41 PM   #7
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Hrmmm... I was thinking of chugging, not lugging. Something to pay attention to, the transmission shifts to second as soon as 10mph, and third 18-20. Once the car is warm enough (just not cold) it will lock up the torque converter in third at 36mph, this could feel like another shift. When the torque converter is locked up, any kind of misfires are amplified as the entire driveline is locked solid. Remember too, any time the brake pedal is used, the computer unlocks the torque converter (even by lightly dragging the brakes, you can feel it unlock).

Knowing how the vehicle should behave, and what its tendencies are half the battle, the other half is getting running the way it should.
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Old 04-11-2012, 07:16 PM   #8
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Good info there, Thanks..

I'm definitely noticing the converter lockup right around 36 mph, it does feel a bit like a shift..
That must be what is producing the initial "lugging" sensations..
1 - 2 - 3 shifting seems & feels "normal", and varies as it should with throttle setting.
At 45 mph or so there seems to be another "shift" and then the car really feels like it'* "lugging" - that must be the OD kicking in..

Good tip about a light brush on the brake pedal to unlock the converter, this is very hilly terrain around here, and it seems to take excessive throttle (in my opinion) to kick it down out of lockup.

Question: Is it a function of the brake light switch that tells the computer to unlock the converter..?
If so, figure out which switch terminals & wires control that function & rig up a pushbutton switch to kick it out of lockup and/or OD on grades without having to actually apply the brakes or depress the throttle so far lol..
Sort of like the electric kickdown switch on an old TH400 but operated via pushbutton instead of your throttle foot..

rjolly87 - "Knowing how the vehicle should behave, and what its tendencies are half the battle, the other half is getting running the way it should."

Words to live by right there, folks..
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Old 04-11-2012, 07:21 PM   #9
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Or, another easy way to do it is, let goes of the gas. When the PCM sees 0% at the TPS sensor, it will automatically unlock the TCC.

If you decide to go the switch route(which I strongly object against), use a momentary switch.
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Old 04-11-2012, 07:21 PM   #10
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