i did it on a 96 impala ss with the '4L60E' trans,by putting a jumper wire with a toggle switch across the brake light switch circuit ( so that when the switch was activated, the trans "thought" the brake lights were on and unlocked the torque converter...). i would be interested if this can be done on our trucks too ( so that i can keep it unlocked untill i want it locked up--it always seems to lock at the most inopportune times, thus giving me the dreaded 'smoky bogs'....) . and the impala one worked like normal when you stepped on the brake, unlocking the converter before you stop. any ideas how to go about it ? anything not so kosher about this idea, and why ? let me know, gentlemen ( and ladies...) as you are all a world of wealth smarter than my a$$, and have proved it time and time again ! thank you....

 

i drive a low mileage truck with a correctly setup E40D.
imho,when properly set,there is no desire to alter the lock or unlock state of the converter from the factory settings.
perhaps (and most likely) your TPS adjustment is incorrect.

D-2-3-lock-OD
press fuel enough to downshift (it shouldn't require WOT or anything) -unlock + 3rd followed by re-lock (re-lock duration is load dependent. still 3rd) - WOT- unlock 2nd revving to it's max,ip governor holding her back.truck moving and about to brake the speed limit very quickly if you don't let off on the flat - 3rd/lock - OD still locked.
(i guess it very,very quickly unlocks/locks between 3rd lock-OD,but it's much to quick to feel.)
while going down hill - let completely off the fuel - unlock + coast clutch = very low, neutral/idle like rpms for increased fuel economy.


if you feel like locking the converter sooner to get more power,this means the converter is no longer multiply torque as it should.the stall is too high.this happens when the converter wares out.the fins in the converter are likely bent much to much causing a massive reduction of power getting to the ground.
it should pull harder before lockup.when it's unlocked it's acting like a gear multiplier.this is why auto's are rated to tow more than manuals.
once locked,it's just like a manual trans.clutches in the converter act exactly like the clutch in front of a manual trans,and directly connect the engine to the trans.

the problem?
the stock converters were set with a too high stall stock as is.
when they ware,stall increases.
when weight is added stall increases.
now you have a heavy truck,load it,perhaps hook a trailer on,and the worn out converter simply stalls much too late,beyond the diesels peak torque band,and the truck takes off like mush.one member said it best,as if your stuck in the mud.
they were known for being the weakest link to the E40D trans.

the solution,
it's not lockup the converter up so you bypass the issue.
that's just prolonging the inevitable. which is a converter that finally fails the whole way and actually comes apart. that can cost you a whole trans.
rather it's replacing the worn out converter.one step further if funds allow,is to buy a converter with stronger clutch(es) with a more realistic lower stall to launch your truck just above idle where all the grunt from the diesel is.

if at 35mph (or so) when lockup occurs feels poor,then your engine is down on power,and you'd feel just as doggy if you had a Zf5 anyway,and rather than mask the performance issue by having an open converter (which causes more heat,and reduced fuel economy) you should resolve the engine performance issue.
now if your setup correctly thus far,let me share a tip that goes very good right here.if you don't have a diesel timing meter,focus your timing by feel adjustments right here.when engine timing is very close (much better than just ball park by ear) you'll notice when lockup occurs,your hardly feel a decrease in performance.she'll keep pulling hard in this now "manual trans/direct connected" state if you will (locked converter.)
engine timing is very sensitive.using the lockup of the converter to fine tune is pretty dang good.only reason i know this was experimenting with my meter.i learned if i had no meter, id use the lockup to guide me.

start with this:
https://www.ford-trucks.com/forums/1...ions-only.html

and then,start playing with engine timing by feel (unless of course you have a meter? but most don't.) you'll get it.
the results of a properly tuned engine and trans,will surpass that of a lockup switch by far.

 

Unless you are lazy, why would you feel doggy with a ZF5.

 

no, i DONT want the converter to lock so that i can pull a 5000lb truck ( behind my 9780lb truck ,my 300lb a$$, and another 500lbs of miscellanious 'stuff' like straps, gas,chains,etc...) without it bogging out--even with the turbo these trucks are somewhat underpowered as we all know. it seems to lock too soon, before the truck can pull the load.

 

what speed is it locking up at?
what are the idle and WOT voltages of the center wire of the TPS?

if you think you really need to;
https://www.ford-trucks.com/forums/6...l#post10906711

that sounds like retarded engine timing to me though.
Gary (icanfixall on OBN) rents timing meter's.
the con's of locking the converter (past the 35 mph ish speed in 3rd) latter, is of course reduced fuel economy,and higher trans temps.be sure you have a temp gauge.

 

F250....I think he is looking to be able to control it 'unlocked' rather than locked. In other words he wants it to slip more than it is now.

Though I will agree that will raise the tranny temps, so a gauge would be a good idea.

Now, been a while since chip was hanging around, so can't recall what his truck did and didn't have done to it. You could be right in thinking that the tranny may be okay, but the engine needs some tweaking to match them up again, things like timing, etc.

Are you still towing chip, or did you get out of that all together?

 

yep, still towing. and youre right, i actually want it to slip more-when it locks up it bogs drastically if im not over 1800rpm when it locks. this is with a full load, of course.

 

yup.i understood,but didn't say so clearly.my bad.
the issue imho,is most likely retarded engine timing,or incorrectly set TPS,or a combo of both.
by unlocking (or not allowing locking rather) the converter to help aid the trucks performance passed it's factory scheduled lockup,not only will reduce an engine already operating at a decreased efficiency range,but lessen it even more.the result will be more stress on the trans and the engine, by trying to compensate for the improper adjustments/tune state of them.fuel economy will suffer as well of course.
a multi meter,timing meter and a little time spent, can make a world of difference making the lockup mod pointless (i know iv tried it for a bit after running the wires in the cab for diagnoses of code 62.)

after properly setting the TPS (preferably replacing it if it's old,or at least carefully testing it's sweep) :
https://www.ford-trucks.com/forums/1...ions-only.html

(don't "baby" her for this test. )
if you have no timing meter.you can get timing very close with the E40D's converter;
take your truck out to a hill (or load it up/hook onto a trailer etc.anything to get the engine under load good.)
make small adjustments to engine timing (pass side advances-never adjust with engine running!) until you no longer feel the engine bog out and fall on it's face when the converter locks up (this is the semi shift you feel around 35 mph or so) one you get it correct,you'll notice she still pulls nice and strong after converter lockup.your likely going to feel nervous about all the extra diesel "rattle". try to remain clam.that is normal.take your time setting the TPS and timing.you will hit the sweet spot,and when you do...........you'll be pleasantly surprised.
you'll quickly learn tiny (tiny is an understatement) adjustments of both of these things,will drastically alter the feel of the whole truck.

 

I know when my e4od locks up (going up a hill mind you). It just keeps pulling and i gain speed going up hill with no additional throttle! . Still have to put the thermostat in for the transmission she is running cold and doesn't like to lock as much. Mileage is really taking a hit too. My truck has a rebuilt by jasper e4od in 2002 with about 120,000 on it.

 

i dont know what my tps is set at, the trans actually acts 'reversed'---when you at part throttle, shifts nice and hard and on time. when you at hard throttle shifts too soon and too soft...and its got the banks transcommand, but didnt seem to make a difference plugged i or not still acts same way. gotta mess with the timing this weekend if i can get around to it--doing the 454 build to swap in the vette too.

 

this may be what you are looking for
https://www.ford-trucks.com/forums/1...converter.html