TC Lock-Up Switch
- Thread starter bullfrogjohnson
- Start date
i just reveiwed a log and my rpm slip is under 500 rpm by 30 mph and stays under till it locks.... starts locking @ 47 and is locked by 50 mph or so ? maybe in my case i could cammand it ealier and it may work ?
My truck acts the exact same way as what your saying and I have an 04. I've tried all kinds of different trans tunes, no change.
I agree with what Ben is saying. I think the TCM sees too much slip in the converter and prohibits lockup. I think there is something in the TCM that is keeping it from commanding converter lockup with X amount of slip. A looser converter compounds the problem, and it can't be fixed with the TCM tune because the table that regulates it isn't available to us.
I went back to some of my videos and it sounds like my converter locks about midway through 3rd gear. 1058 converter at around 500 rwhp. http://www.youtube.com/watch?v=N1AhRHkokb8
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How about a pin number to wire up the lock up light, this way I know when it locks and I am not going by the feel.
I would have to say that some of my problem is in the tuning. I just dont know where
Do a search rookie
http://www.duramaxdiesels.com/forum/showthread.php?t=4454&highlight=converter+lock+light
Going off what I saw that doesn't seem to fit.
Launching soft I had more tcc slip (higher RPM vs mph) yet it still locked in 2nd. Launching harder I had less slip (lower RPM vs mph) but it didn't lock until 3rd.
I have a 1986 4X4 with a 383 Stroker, (running on C3) Supercharger, 37" Superswampers, with a 700R4 and 4:10 gears. I have a TC Lockup switch on it. Before installing the lockup the truck ran at 2400 rpm @ 80 km/hour. After installing the switch it barely breaks a sweat, running around 1700 rpm @ 100 km/hour. I don't drive the truck in the winter but when I drive the truck I leave the switch "on" all the time.
the tcm is only going to reference input VS output shaft speed . you have to log it to know if that holds true or not . for mine i need to also log and see when the cammand was given , because the TC slip was under 500 after 30 mph , but if it wasnt cammanded then what ben said may still hold true .... if it was cammanded then its something else keeping it from locking.
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These units will snap shafts under the power most of us run. I have had to repair a few of them.
no Dustin you need to log the TCM...
turbine vs. input speed is what I am talking about.
ben
every built up dmax that Ive seen that has an allison thats anal about lockup, its never been a physical/mechanical problem.
ie; the command is simply not given until ~50mph when the tcc slip rpm gets within an acceptable range.
If EFILive could find this table, we would not need a lockup controller, because the stupid TCM would lock it when its supposed to!
D5072 is sort of on the right track to what we need. Ive played with it and it does make lockup harsher/softer/faster/slower, but there is still one more table that overrides it.
However, im not sure D5072 is labeled correctly. Because of the way the allison works, it doesnt really reference anything in PSI, because pressure is fixed by the converter flow valve; the TCM cant control pressure to the torque converter. So all the values in D5072, I dont think those numbers are PSI. Something else...
ben
ie; the command is simply not given until ~50mph when the tcc slip rpm gets within an acceptable range.
If EFILive could find this table, we would not need a lockup controller, because the stupid TCM would lock it when its supposed to!
D5072 is sort of on the right track to what we need. Ive played with it and it does make lockup harsher/softer/faster/slower, but there is still one more table that overrides it.
However, im not sure D5072 is labeled correctly. Because of the way the allison works, it doesnt really reference anything in PSI, because pressure is fixed by the converter flow valve; the TCM cant control pressure to the torque converter. So all the values in D5072, I dont think those numbers are PSI. Something else...
ben
i was looking @ D5072 ealier today ..... anything you have found work well , wasnt shure were to start ( torque amount) to increase the engagement speed a bit ?
Wonder if we could drop the input speed sensor in a little deeper in the bellhousing to get a better signal.
I had a light wired in (rigged in more like it) at Famoso last year. I was locking in 2nd gear, everything seemed fine. I had a intermittent problem on a run but the rest looked good and lockup looked and felt great. I'll try to get a light hooked up again and see if I am still seeing that. I wasnt really paying much attention to lock up back then as it felt great.
12.7 run, with a 1058, my TCM tuning.
Also I have had people in my truck that have 1058s and they think my truck feels way different than theirs. What did you do differnt to mine Mike lol
12.7 run, with a 1058, my TCM tuning.
Also I have had people in my truck that have 1058s and they think my truck feels way different than theirs. What did you do differnt to mine Mike
lol
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Mike Im running 4L80 speed sensors in mine. With this refreshed 1057 lockup IS definetly a little faster because the converter isnt loosey-goosey, but still, it sometimes wont lock until 3rd gear.
ben
ben