Torque converter lockup Mod...

I've got the E4OD in my truck. It works great for me, my only complaint is that the torque converter lockup comes and goes whenever, and isn't always when I think it should happen. It messes up the nice shift pattern Ford built into the trans.

So, I've done the mod where you put in a switch to override the lockup.
I did it for 2 reasons. One, to not lockup in town, and so the trans shifts 1,2,3,4, like it should nice smooth even pattern.
The second is to be able to lock it when I want to such as uphill pulling a big load, or downhill decelerating.

I also wanted to have the option of leaving it in the "Automatic" setting so that the wife (and now kids) can drive it whithout worrying about it.

So, I put in 2 switches. cut the wire from the solenoid in the trans back to the computer. On the first switch, I put each end of this wire. When the switch is in the "off" setting, the computer cannot make the connection, and the lockup will not occur. In the "on" setting, the computer is connected and lockup occurs as it normally would as controlled by the computer.

I then ran a wire from the computer terminal on this first switch to another switch. The other terminal goes directly to ground. In the "off" position, the first switch acts as before. However, when the first switch is in the "on" position, activating the second switch provides constant ground to the solenoid, and the lockup will stay engaged, no matter what the computer thinks.(The computer has to stay wired in this setup or it causes the OD light to start to flash, and the trans will go into "limp" mode)(manual controlled lockup).

This mod works great. This prevents the lockup from happening everytime you take your foot off the pedal, or apply the brake a bit. You can use it to decelerate downhill, and keep it locked uphil even down into second gear. Should increase fuel economy, will definately increase longevity of the torque converter lockup clutch, and gives much more control over how the truck drives. Much nicer shifting in town too.

Just got to remember to unlock before coming to a stop.

Zigg

i recently did the same thing on mine. love it! its so much nicer having a nice firm shift into second gear. i hate the shift feeling and then the tc lockup in second. weird feeling. idk i simply used a double pole switch from autozone. in the left position the tc is locked, middle-unlocked, right-automatic. its really nice when you tow a heavy load. its like having a manual again. lets you use that low end torque these diesels rely on. my OD light does blink now after a few days driving with the manual lockup. not in limp mode as it still shifts fine and goes into OD if its not causin a problem im not gonna fix it. cost me all of $6 and about 15 minutes. best mod so far!

Zigg - you could do that with one switch instead of having two switches... get a double throw switch.

I did my lockup conversion a several years ago.My trans is high mileage now over 200k-mostly towing as I have said many times B4.It still shifts as good as new only difference (maybe its my senility kicking in)is it seems to shift softer when in auto lock up mode then it used to but still no slippage.I had the trans in our 2003 park ave worked on -asked them to drive my truck they said it was perfect.How long these transmissions can go with proper rebuild & maintainence I don't know,but I am impressed whith them-much better then my ole C6 was.I never used an E40D to plow snow with so I can't elaborate there ,I did however loose a newly rebuilt C6 twice -once in a blizzard when the grill filled with snow over heating it,once when pulling a load up a gravel hill-the wheel hopped over a rock and snapped the main out put shaft.I don't want to take a long trip in it towing now only because of the high mileage not because of how it works.Maybe I need to get over the fear of it failing.I believe Zigg & Sootman are on the money with this mod.I loved it when it would help slow the truck down on grades and if i let off on the highway because someone pulled in front of me going slower(it happens a lot when you are pulling trailers)I could just let up no brake needed and felling of slippage if I needed to re accelerate hard after slowing down on the highway.After I had the trottle switch adjusted I had a lot of control over the shifting with the throttle pedal-so the shifts weren't real harsh even when locked up.Good Job guys. Keep it cool -keep it locked.

argve said:

Zigg - you could do that with one switch instead of having two switches... get a double throw switch.

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Travis

Yeah, I thought the same thing, but,

Well, actually it doesn't work like you'd think. I did originally wire it up with a double throw switch, but as Ben said in the above post, when in the manual mode(trans direct to ground without the computer in the loop) the OD light will flash, and the trans goes into limp mode. I dunno why, but it does.

So, I wired it up with the second switch off the computer side, and that way the computer still sees the lockup, and seems happy. So, I still have Automatic, no lockup at all for in town, and manual control when called for, and I can switch them on/off at will. The only other thing is that the main switch has to be in "auto" mode before getting up to hwy speed, or again when the second switch is thrown to "manual" position, the Limp mode kicks in again with the associated harsh shifts.

Sounds kinda complicated but not really. Off for in town. Switch to Auto when heading out onto the hwy, and then flip the manual on/off at will anytime after that.

I actually like the idea of the second switch. I have the first one on the right by a bunch of others (accessory lights, glow plug off etc.,) and the second one is over on the left behind the turn signal. That way, no-one can accidentally bump it into the manual mode when moving around on the bench seat. It pretty much has to be switched on, on purpose. Prevents one of the kids from knocking it in when I'm not aware, or when you haven't started it up yet or something...I don't think that'd do the trans any favours...

Zigg

so this helps with the sluggish shift from 1-2?

Then we still have current flowing... hummm interesting....

The reason the computer gets pissed off is because it probably measures the resistance or voltage in the lock up coil, and if it is to high or low, it considers that a fault. Measure the resistance, and when you ground the TC, provide the computer with the replacement 12 volts through a resistor of equal value so it thinks it's controlling something.

what about using the BTS convertor?

i was wondering what wires i will need to tap into to hook up a manual lockup switch for my 1990 7.3 IDI. i have been searching and searching and i cannot find anything on where to tap into for this switch.

robmoore11 said:

i was wondering what wires i will need to tap into to hook up a manual lockup switch for my 1990 7.3 IDI. i have been searching and searching and i cannot find anything on where to tap into for this switch.

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http://www.oilburners.net/forums/showthread.php?t=43777

So would this be what I am looking for just so I have control over the tc. I just want to be able to lock manually with a switch while I am towing my trailer. There are more choices for fords then for dodges with the tc lockup. from what I understood this mod I copy and pasted is just for torque converters that like to lock and unlock at random times and this prevents that from happening?



Basically, you find the purple wire with the yellow stripe in the transmission harness about 4 inches from the plug. Cut it. What you want to do is then extend the wires into the truck cab. I chose to go up through the floor where the transmission shifter cable comes through the floor, but it's up to you where you do this. I used RED on the computer side of the wire, and BLACK on the transmission side...it made the wiring easier when I was in the cab.

ALL FOLLOWING TESTING IS TO BE DONE IN PARK ONLY!!

Start the truck, and check for voltage on the red and black wires separately... the RED wire should have 12- 14 volts, and the BLACK wire should have 0.5 - 3 volts. Use a multi-meter and use the cigarette lighter outer ring as a ground..it's a perfect ground if it works. If this is the case, shut the engine off.

Just be carefull using the lockup mod below 40 MPH, it's really ******* the transmission.

yeah i know about that. i had it done on my dodge that i had. but the problem is i dont know what option to choose for the ford. i dont mind if the OD light is flashing as long as its not going to cause any damage. all i want is a switch that i can flick to lock the TC while im towing my trailer. it was very simple with my dodge because i ran 2 wires into the cab, one from the main harness and one from the ground i beleive and hook into a switch. very simple haha.

OLDBULL8 said:

Just be carefull using the lockup mod below 40 MPH, it's really ******* the transmission.

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Can you explain why a little more. Mine will lock in third at 25mph any lower and it shifts down. That's just with the b&m shift kit. No lock up mod.