wonderer
Member
- Joined
- March 21, 2003
- Messages
- 40
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- City, State
- Sparta WI
- Year, Model & Trim Level
- 92' 4X4 EB
Torque converter lock up switch.
I finally got around to trying the torque converter lock up switch idea and the results are in…
I was disappointed to find out Ford has the worst system I’ve come across so far…
First a brief summary:
I originally tried this idea to save some fuel and wear and tear. When cruising around town, when its cold, or driving at speeds less than about 40mph , the Torque converter never gets locked up. It slips and creates lots of heat and makes the engine rpms rev about 2 to 1 against a manual transmission in the same gear, which of course, all that wasted heat and energy is also wasted gas.
After the original idea came another reason: to get rid of excessive heat build up in the tranny… I bought this Explorer with the intentions of pulling a 23’ Jayco travel trailer, (7’ X 7’ frontal area , 3400 lbs empty, 4400 fully loaded). This will be fairly to extremely hard on my poor old SUV and it’s gonna need all the help I can give it. I figured if I could get it to lock up in 1rst and 2nd, I could keep the heat generation way down. Unfortunately, the A4LD doesn’t allow lock up in these 2 gears at all.
Fortunately , it WILL allow lock up in drive above 30mph which means you can keep it locked while merging into interstate traffic pulling a boat or more, like in my case lol. 20 seconds of all-out floor-boarding will cook tranny oil to some extent even before it can get to the tranny coolers. Another approach is city driving at 30 – 45 mph , hit the switch and get rid of extra heat and maybe save some fuel.
I wired my Explorer up for both TC lock up and forced OD gear mode, but it functioned differently than I thought it would.
The way the lock-ups on my other 2 vehicles have worked is like this…
1rst gear: No affect
2nd gear: No affect
Drive: Locks up Torque converter at ANY speed as long as it stays in drive, (about 20-25 mph with no throttle should get it into drive, and it will still kick down into 2nd with enough pedal).
Now Ford’s wacky A4LD:
1rst gear: No affect
2nd gear: No affect
3rd gear: On my Ex, it will not work initially upon dropping into drive. It needs to climb to about 30 mph in drive before some other determining force in the tranny decides it’s time to let the lockup clutch engage, it would however, after locking up, let it stay locked all the way down to lugging 20 mph or so , basically until it shifted back into 2nd on the way to a stop. Normally it will lock up on its own at about 43 or so when it’s warmed up and with no interference from the switch.
I’m not sure about the rest of the world’s opinion on the OD switch, but I’m convinced it has no purpose. Lock up has it’s advantages still, even with the wacky shift, but the OD switch showed very little if any useful function, other than holding it in OD forcefully. In my opinion is that this V6 is already under powered pretty much anytime it goes into OD and if it’s wanting to kick out of OD, its probably doing the right thing! Another reason for not having a “force OD gear” switch is that I found you could get it into OD WITHOUT lock-up. This would increase the gear ratio even further out of the power band and cause more slipping of the torque converter and more heat build up then if left in 3rd and we all know what heat does to our trannys : (.
To those who are interested in playing around with the idea, I’ve included the following info:
!!!WARNING!!!
1. The controller that engages lock up and OD will be damaged if you short it’s output wires to B+ OR attempt to hold the output at a voltage greater than .7 volts. If you make connections to this circuit, I advise that you install a .75 or 1 amp , 250 volt fuse inline to the switch mentioned below, this will help prevent damage to the computer, (very expensive) .
2. A short in the added wiring or existing wiring or miss-use of the switch, may cause the torque converter to lock up unexpectedly, and cause erratic shifting.
3. Use of this idea is EXPERIMENTAL use it at your own risk!
4. Wire colors very from year to year and model to model, don’t use the wrong ones!
Ford has a simple computer output that was easy to modify, (class C transistor output stage).
On the driver’s fender, there is a pair of wire harnesses and plugs. The group of wires involved here, come from the tranny, up over the driver’s side engine head, go to the front of the engine and then go across to the fender, pretty much directly over the front tire.
On the 1992 Explorer, the torque converter lock up solenoid wire is purple with yellow stripe and the overdrive (3-4 shift) solenoid is orange with yellow stripe. I think a few years used these colors, but beware, there are other colored wires for this function! The 91’ uses white and tan/white wires for example. The best way to tell is to get a repair manual that shows these wires and how they are connected. I used the Chilton 1991-99 Ford Ranger/Explorer/Mountaineer manual #26688.
I attached wires to the orange/yellow, (overdrive) and the purple/yellow(TC lock-up), and ran them through the firewall just below the power brake module , (there is an access panel you can remove or drill through, and a pre-punched hole in the floor padding there). I soldered them in place for reliability reasons , but crimp splices or wire nuts would work ok. I hooked one side of a momentary push-button switch, (Radio Shack part #275-011), to the newly spliced wire and the other side of the switch to chassis ground.
You really need to search for a good ground in that thing! The dash doesn’t seem to be grounded well at all, I tried from the key switch, (which is ground most of the time if you wiggle it a little), to lots of different locations and finally found a good enough ground on the park brake mounting bolt, you need to scrape the paint off the back side of the washer to get a good connection. There are probably better ways to ground that wire but I got tired of searching, maybe in the fuse box somewhere?
I’m one to take shortcuts if at all possible so I just drilled a hole through a 1” X 2” X 3” long chunk of pine board and slipped the switch into it, making sure the hole was just big enough for the switch shank with the nut removed, would fit and not the larger area on the bezel. Then I gooped up the back side with GE clear silicon sealer, waited for it to dry and attached a strip of Velcro to the back to make it adjustable or movable so you can move it out of the way then nobody else hits it by accident.
Be careful when using this thing, it might be possible to damage something if you engage it at the wrong time with too much throttle etc.
I have one question for the tranny pros out there… Is there a way to make this thing work in L1 or L2 ???
P.S. I have a nice drawing of this modified schematic, but I can't seem to post it here
.
I finally got around to trying the torque converter lock up switch idea and the results are in…
I was disappointed to find out Ford has the worst system I’ve come across so far…
First a brief summary:
I originally tried this idea to save some fuel and wear and tear. When cruising around town, when its cold, or driving at speeds less than about 40mph , the Torque converter never gets locked up. It slips and creates lots of heat and makes the engine rpms rev about 2 to 1 against a manual transmission in the same gear, which of course, all that wasted heat and energy is also wasted gas.
After the original idea came another reason: to get rid of excessive heat build up in the tranny… I bought this Explorer with the intentions of pulling a 23’ Jayco travel trailer, (7’ X 7’ frontal area , 3400 lbs empty, 4400 fully loaded). This will be fairly to extremely hard on my poor old SUV and it’s gonna need all the help I can give it. I figured if I could get it to lock up in 1rst and 2nd, I could keep the heat generation way down. Unfortunately, the A4LD doesn’t allow lock up in these 2 gears at all.
Fortunately , it WILL allow lock up in drive above 30mph which means you can keep it locked while merging into interstate traffic pulling a boat or more, like in my case lol. 20 seconds of all-out floor-boarding will cook tranny oil to some extent even before it can get to the tranny coolers. Another approach is city driving at 30 – 45 mph , hit the switch and get rid of extra heat and maybe save some fuel.
I wired my Explorer up for both TC lock up and forced OD gear mode, but it functioned differently than I thought it would.
The way the lock-ups on my other 2 vehicles have worked is like this…
1rst gear: No affect
2nd gear: No affect
Drive: Locks up Torque converter at ANY speed as long as it stays in drive, (about 20-25 mph with no throttle should get it into drive, and it will still kick down into 2nd with enough pedal).
Now Ford’s wacky A4LD:
1rst gear: No affect
2nd gear: No affect
3rd gear: On my Ex, it will not work initially upon dropping into drive. It needs to climb to about 30 mph in drive before some other determining force in the tranny decides it’s time to let the lockup clutch engage, it would however, after locking up, let it stay locked all the way down to lugging 20 mph or so , basically until it shifted back into 2nd on the way to a stop. Normally it will lock up on its own at about 43 or so when it’s warmed up and with no interference from the switch.
I’m not sure about the rest of the world’s opinion on the OD switch, but I’m convinced it has no purpose. Lock up has it’s advantages still, even with the wacky shift, but the OD switch showed very little if any useful function, other than holding it in OD forcefully. In my opinion is that this V6 is already under powered pretty much anytime it goes into OD and if it’s wanting to kick out of OD, its probably doing the right thing! Another reason for not having a “force OD gear” switch is that I found you could get it into OD WITHOUT lock-up. This would increase the gear ratio even further out of the power band and cause more slipping of the torque converter and more heat build up then if left in 3rd and we all know what heat does to our trannys : (.
To those who are interested in playing around with the idea, I’ve included the following info:
!!!WARNING!!!
1. The controller that engages lock up and OD will be damaged if you short it’s output wires to B+ OR attempt to hold the output at a voltage greater than .7 volts. If you make connections to this circuit, I advise that you install a .75 or 1 amp , 250 volt fuse inline to the switch mentioned below, this will help prevent damage to the computer, (very expensive) .
2. A short in the added wiring or existing wiring or miss-use of the switch, may cause the torque converter to lock up unexpectedly, and cause erratic shifting.
3. Use of this idea is EXPERIMENTAL use it at your own risk!
4. Wire colors very from year to year and model to model, don’t use the wrong ones!
Ford has a simple computer output that was easy to modify, (class C transistor output stage).
On the driver’s fender, there is a pair of wire harnesses and plugs. The group of wires involved here, come from the tranny, up over the driver’s side engine head, go to the front of the engine and then go across to the fender, pretty much directly over the front tire.
On the 1992 Explorer, the torque converter lock up solenoid wire is purple with yellow stripe and the overdrive (3-4 shift) solenoid is orange with yellow stripe. I think a few years used these colors, but beware, there are other colored wires for this function! The 91’ uses white and tan/white wires for example. The best way to tell is to get a repair manual that shows these wires and how they are connected. I used the Chilton 1991-99 Ford Ranger/Explorer/Mountaineer manual #26688.
I attached wires to the orange/yellow, (overdrive) and the purple/yellow(TC lock-up), and ran them through the firewall just below the power brake module , (there is an access panel you can remove or drill through, and a pre-punched hole in the floor padding there). I soldered them in place for reliability reasons , but crimp splices or wire nuts would work ok. I hooked one side of a momentary push-button switch, (Radio Shack part #275-011), to the newly spliced wire and the other side of the switch to chassis ground.
You really need to search for a good ground in that thing! The dash doesn’t seem to be grounded well at all, I tried from the key switch, (which is ground most of the time if you wiggle it a little), to lots of different locations and finally found a good enough ground on the park brake mounting bolt, you need to scrape the paint off the back side of the washer to get a good connection. There are probably better ways to ground that wire but I got tired of searching, maybe in the fuse box somewhere?
I’m one to take shortcuts if at all possible so I just drilled a hole through a 1” X 2” X 3” long chunk of pine board and slipped the switch into it, making sure the hole was just big enough for the switch shank with the nut removed, would fit and not the larger area on the bezel. Then I gooped up the back side with GE clear silicon sealer, waited for it to dry and attached a strip of Velcro to the back to make it adjustable or movable so you can move it out of the way then nobody else hits it by accident.
Be careful when using this thing, it might be possible to damage something if you engage it at the wrong time with too much throttle etc.
I have one question for the tranny pros out there… Is there a way to make this thing work in L1 or L2 ???
P.S. I have a nice drawing of this modified schematic, but I can't seem to post it here
.
