Auto transmission floor shifter

[Bill Blue]

You guys that are using A4LD trannies, what are you using to shift them? Need to know the floor shifter I need and where to find it.

Bill

 

[Bill Eisinger]

I am using a shifter from an Aerostar van. They used the A4LD from the mid-80's to about '91 or so. I pulled it out of a junkyard and it looks like it can be nicely restored to look like new. It has the correct number of positions to utilize the OD. Going to use a cable shift set up as there isn't room to easily utilize a mechanical linkage. I'm using the pressure switch method to facilitate OD lockup.

 

[Bill Blue]

Yes, it looks like a winner. Is the cable mechanism used in the van?

Bill

 

[Bill Eisinger]

I’m not sure what the shift set up is in the van....Summit sells all kinds of shift cables in various lengths so I just bought one there...you can find the correct cable bracket for the transmission on EBay (or just fab one)...at the shifter end it looks pretty simple to just a fab up a little bracket to terminate the cable on.

 

[Bill Blue]

Bill, could you explain how your transmission functions with the pressure switch facilitating OD lockup? Exactly what happens and when. Please start with meanings. To me, lockup refers to the torque convertor and OD is 4th gear. Does the lockup occur only when in 4th? I am a life long manual trans guy, have owned a few (very few and never really got into them) automatics and am finding the A4LD to be a mystery.

Bill

 

[Charles Johns]

Bill Eisinger, THANKS for the heads-up on the shifter. I am using an A4LD with a Push-on-push-off button to engage the torque converter lock-up. I was asked what happens if I forget to unlock the lock-up? I told him, the same thing that happens if you forget to push in on the clutch pedal with a standard. You won't do it but once or twice. Muscle memory is a wonderful thing.

 

[husky drvr]

Bill Eisinger, THANKS for the heads-up on the shifter. I am using an A4LD with a Push-on-push-off button to engage the torque converter lock-up. I was asked what happens if I forget to unlock the lock-up? I told him, the same thing that happens if you forget to push in on the clutch pedal with a standard. You won't do it but once or twice. Muscle memory is a wonderful thing.

Charles,

Have you considered using a relay that electronically latches and then uses a brake pedal switch to trigger unlatching the relay automatically? That's how the gear shift position operates turning off the overdrive in the later Alpines.

That might make your setup a bit safer in case of having to make an emergency stop.

 

[Bill Eisinger]

To me, lockup refers to the torque convertor and OD is 4th gear. Does the lockup occur only when in 4th? I am a life long manual trans guy, have owned a few (very few and never really got into them) automatics and am finding the A4LD to be a mystery.

Bill

Bill - my knowledge of the A4LD could probably be written on the head of a pin but, yes, the OD is essentially the 4th gear. The purpose of the torque convertor lockup is to reduce slippage and increase efficiency when in the 1:1 OD gear.

All A4LD's have a lockup solenoid that, in the original vehicle such as a Ranger or Bronco, is triggered by a signal from the EEC computer which applies 12 volts to the solenoid....I'm not exactly sure what the signal parameters are but I believe it's based on a combination of rpm and throttle position. Basically, all that the solenoid does is initiate a hydraulic operation within the valve body that triggers the convertor lockup clutch by the plunger simply moving in or out.

Since we don't have a computer in the Alpine we need a work around to apply the 12 volts to the lockup solenoid....the two common ways are via a manual switch or a pressure activated switch. The pressure activated switch method is well documented on various sites such as www.therangerstation.com.

Basically, the pressure switch is installed in the governor portion of the transmission which is in the tail extension. When the fluid pressure reaches the level that the switch is calibrated for (typically about 50 PSI) the switch closes and triggers the solenoid. It's not a perfect science and may require experimenting with a couple different pressure switches to achieve results but the target is to have the lockup engage in the 45-50 mph range.

As to your question about the lock-up engaging in other gears, it is my understanding that the lockup clutch is by-passed in 1-2 but not in 3-4. I personally don't see an issue with lockup engaging in third gear...the downside might be a rougher shift to 4th than otherwise but I think with normal operation you would pretty much always be in 4th gear by the time the lockup is engaged.

With regard to braking or forgetting to unlock it....when the car slows down, the pressure drops and the switch opens up so you don't need to do anything else.

But, to add a little confusion to the mix, there are two versions of the A4LD. The earlier versions (I believe 1985-1988) employed a single solenoid for the lockup function and the 3-4 shift function was vacuum driven. The later versions employed a second solenoid that triggered the 3-4 shift with another signal from the EEC. The way you can tell if you have a single solenoid or dual solenoid is to look at the electrical plug on the side of the transmission...if there are two wires you have only the lockup solenoid....if there are three wires you also have the shift solenoid. So, to get into 4th (or OD gear) you have to also trigger that second solenoid.

I'm not exactly sure what the course of action should be for the later versions.....perhaps you just wire both solenoids in parallel and trigger them simultaneously either manually or via the pressure switch....I don't know enough about the A4LD to know if it's a problem to do both functions at once or if they should be initiated separately....i.e. shift first and then lockup. I have an earlier version so I haven't had to address that issue.

My transmission is at the rebuild shop and I'm probably still a year away from having the car put together so this is still somewhat all theory in my case. But, as I said, this is all well documented and really not rocket science.

 

[260Alpine]

Bill, the later version A4LD for the 4.0 have had updated Torrington (needle bearings) instead of brass washers and additional clutches. I'd ask the transmission shop to add all the upgraded parts during the rebuild.

 

[260Alpine]

For those who want to build their own:

https://transmissioncenter.net/shop...94-combo-kit-build-your-own-performance-a4ld/

 

[260Alpine]

Bill, Here is your pressure switch:

https://transmissioncenter.net/shop...s-is-an-automatic-engagement-solution-50-psi/

 

[Bill Blue]

The pressure switch initiating lock seems to remove driver input, which is fine. However, let's talk manual mode. Your driving along in 4th - lockup and approach a country traffic signal. You forget to unlock the convertor and shift out of 4th. Looks like a stalled engine situation. With the pressure switch lockup, almost all is well. The convertor would unlock due to reduced pressure and when the light changed you would proceed in 4th, albeit at a leisurely pace.

With no driver input, the pressure lockup trans would be a 3 speed full auto tranny with lockup.

Is this correct? Just trying to determine how I want to do this. As I depart the Golden years full automatic sounds good.

Bill

 

[Bill Eisinger]

I think you have it correct... I guess what I don't know is that if you are in Over Drive and come to a stop and then take off again does the transmission not kick down to 1st and then shift back up through the gears automatically or do you always have to start in "D" and then manually shift to Overdrive. As, I said, I'm far from an expert with this transmission but I would think that it starts out in 1st and then automatically shifts all the way back to 4th (OD) if that's where the gear selector is set...at least with the earlier version of the transmission where the 3-4 shift is controlled by vacuum.

But also, I believe the convertor lockout clutch by passes gears 1-2 so, theoretically, stall shouldn't be an issue once you drop past 3rd unless there is a problem with that lockout clutch in the transmission...I might be all wet on this theory but I believe its the case. Maybe somebody smarter than me can address this.

Either way, I think the pressure switch is a more elegant and reliable solution (because the driver isn't involved) than a manual switch plus I cant' figure out a way to mount a switch on the shifter that doesn't end up looking like some kind crude kluge...

I'm with you on the automatic...I'll never buy/build another manual car again...first so my wife can drive it but also, with the new cars, the auto trans cars are much better performing than manual trans because the computer can select and shift gears far faster than a human...the new Mustangs and Shelby's with the 10 speed paddle shift transmission are incredible performers...one may be gracing my stable soon! I know there are some on here that feel otherwise and go out of their way in the other direction in terms of technology so each to their own...that's what makes the world go around!

 

[Bill Blue]

Bill, I think we can agree that the problem is not our smarts, but our lack of knowledge about the internal workings of the tranny. So to be correct, we are not stupid, we are ignorant.

I noticed that PATC offers a selection of pressure switches. Could a switch of lower threshold be plumbed up with a tee and used to engage 4th? Might have to run the signal through a vacuum switch to keep it from activating while pulling hard.

Bill

 

[260Alpine]

Bill and Bill, With the shifter in OD position it will shift all four gears automatically. If you don't want OD like in hilly country or towing you would use the drive position. The lockup should work only in 4th. There is also an adjustable vacuum modulator to tailor the shift points.

http://www.transmissionpartsusa.com/A4LD_transmission_vacuum_modulator_p/230-00023901m.htm

 

[Aladin Sane]

I stuck with the c4 auto in my alger project, not because I didnt want a stick, but because with the wider trans tunnel required by the v8, I couldnt get three working pedals and my size 14s in the footwell.

 

[Bill Blue]

Jim, could you explain that statement to me? If one solenoid is used to engage the lockup, what is the second one for? I thought it was to shift into 4th.

Bill

 

[260Alpine]

Bill, The second solenoid is on the 89 and later and is indeed a 3-4 shift solenoid. You just need a on/off button for OD.

 

[260Alpine]

Bill, your second pressure switch idea may work. This is on a European Ford Granada but is interesting. Also uses a vacuum switch?

 

[260Alpine]

Bill, this is listed for a different application but is a complete kit:

https://transmissioncenter.net/shop...ick-here-for-727-to-46rh-swap-wiring-diagram/