So I'm thinking of the tranny lock-up mod....

[Fozz]

So after doing some reading, I went and bought a switch to experiment with the torque convertor lock-up mod. But, then I'm thinking, I've got a fresh Ford reman in my truck, isn't the torque convertor locking up at highway speeds already? Assuming a properly operating tranny?

So I guess my question is, for those of you that have done it, other than having control of keeping it locked up while descending long grades with a load (engine braking) what do I have to gain by doing it?, before I start cutting wires?!

 

[Black dawg]

well worth it for engine braking alone. just tee your wire into the lockup wire so that it still functions normally.

 

[LCAM-01XA]

Engine braking effect is awesome, I can descend up to 8% grades idling without ever touching the brakes just as long as I shut the OD off but keep the converter locked and let her "idle" at 2000 rpms or more On a level freeway it makes not much of difference, as the converter is locked there anyways, tis when you let off the throttle when the PCM opens it and that's pretty much only important while decelerating.

 

[oldmisterbill]

Also at highway speeds the convertor does not lock & unlock every time you let off for some lane changer -thus preventing convertor clutch wear.

 

[LCAM-01XA]

There is that. I actually did some upgrades to my system today, now there is a bracket fabricated and welded to the shifter that holds both the TCC and OD switch, sure beats having the TCC switch just held in with a hose clamp, and it makes for a very sweet setup but also one real fat harness for it (went from 3 wires for the TCC to 8 wires for both). I'm debating modifying the TCC lockup logic a bit too, right now tis off-lock so total manual control over the converter, but I'm thinking an auto-lock setup would work better, as there aren't many times I want the converter open, and it would be kinda nice to not worry about it every time I near a stop sign or a light.

 

[Fozz]

Thanks for the replies. I bought a red LED to wire in as well, to indicate when the converter is locked up. Looking to do this mod before my 4th of July trip to try it out. Also going to replace my tranny fluid and put a drain plug in the pan. I'd like to find a nice rocker switch (dpdt on-off/center-on) for a more factory look, but can't find one. Not sure where I want to mount the switch yet.

 

[LCAM-01XA]

I just put in a "new" fuel tank selector switch, the one that came off my truck worked just fine but had the F and R letters worn out, so now tis all black. That switch works just fine, and the replacement one I pulled from the junkyard had harness with it that I am not using. If you want I can mail you my all-black switch and the harness, this way you can wire it any way you want. The tank selector switch is a DPDT switch, by the way.

 

[Fozz]

So I did the lock up mod today, as well as changing out the fluid and installing a drain plug. All went well. I tell ya, as others have said, with the converter lock up off, the tranny shifts a really nice pattern. What seemed like a super sloppy 2 to 3 shift, is really both a 2-3 shift followed closely by the converter locking up. Together, it seems like a slow sloppy shift. With the torque converter lock up off, the tranny shifts nice at good intervals (good for in town driving). The real test will be next weekend when I go camping with the 5r in tow.

M.L.S.C, great idea, thanks for the switch offer! While I was gathering my parts today, I ran across my own fuel tank switch! I had forgotten that I had changed mine out some time ago and kepy my old switch.

 

[LCAM-01XA]

If the camping trip involves any downhills, you will notice you are a whole lot easier on the brakes. So did you use your old tank selector switch for the TCC lockup?

 

[Fozz]

No I didn't. I had already bought a 3-way on/center off/on switch. So I can run normal, always unlocked or always locked. I mounted the unsightly toggle switch in the little cubby hole in my dash, so it is not an eyesore, yet easily accessable. My lockout indicator LED didn't work, I think it was rated at too few amps and burned out. I bought a regular 12v small red bulb and a green. It works, so I have a red light indication when I'm locked up. I'm going to wire up the green one for when I'm switched to normal. My trip up will be uphill, but it'll get a good test coming back home.

 

[FORDF250HDXLT]

how did she end up holding ya back, down the hills on your return trip?

 

[87crewdually]

No I didn't. I had already bought a 3-way on/center off/on switch. So I can run normal, always unlocked or always locked. I mounted the unsightly toggle switch in the little cubby hole in my dash, so it is not an eyesore, yet easily accessable. My lockout indicator LED didn't work, I think it was rated at too few amps and burned out. I bought a regular 12v small red bulb and a green. It works, so I have a red light indication when I'm locked up. I'm going to wire up the green one for when I'm switched to normal. My trip up will be uphill, but it'll get a good test coming back home.

You burnt up your LED if you tried putting battery voltage to it. You would need to run the volts through a resistor to get it down in the 1.2 volt range.

 

[LCAM-01XA]

That depends on the LED tho, as some come with the resistor already built in them, RadioShack has those as I got one to indicate when the switch for the TC is open.

 

[Fozz]

Heck that was a year ago. Yeah, I love the mod and it really does help with downhill braking. A lot (and I mean a lot) less brake usage on long downhill grades. The truck is much more fun to drive now too with the converter not locked up while driving in town.

 

[pedro_8149]

what are the instructions for this and rougly how much time and cost does it take.