Torque converter
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Melting Slicks
Joined: Oct 2010
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From: Tollesboro Kentucky
Torque converter
I noticed yesterday that my torque converter doesn't seem to lock while at cruising speed.I installed a new battery and on the first drive it seemed to do what it was supposed to with RPM at about 1200 at 55-60 MPH.After that,they seem to stay at about 13-1400 with it varying alot with just a small touch of the throttle.It may be nothing but I don't remember it doing this before.It seems like the RPM varies with no change in the speed.It isn't slipping and no codes to be found.Car has 48k miles and has never been abused or raced.Am I just paranoid?
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From: Central MO
You lost the "learned" transmission shifting behavior when you disconnected the battery. It takes a while to relearn. The behavior you describe is normal when the converter is not locked. My converter typically doesn't lock in 6th and stay that way until about 65. It unlocks pretty quickly at 55-60 on any additional throttle input on an uphill incline.
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You lost the "learned" transmission shifting behavior when you disconnected the battery. It takes a while to relearn. The behavior you describe is normal when the converter is not locked. My converter typically doesn't lock in 6th and stay that way until about 65. It unlocks pretty quickly at 55-60 on any additional throttle input on an uphill incline.
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From: Central MO
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Didn't say anything about it affecting torque converter lock. Just indicated it won't shift the same as it did because of losing that learned behavior. And that the behavior he described was normal when the converter isn't locked. Compared my car's converter locking behavior to his mph description to give him a data point comparison to his. Difference in post interpretation, I guess.
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From: Central MO
Still doesn't shift the same as after many miles of learned behavior, but you win.
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By your logic, my car won't shift properly because of losing the so-called learned behavior but I can assure you it shifts just fine at 7500RPM and beyond, without the ability to put any street miles on it since it's now a dedicated race car.
Last edited by subfloor@centurytrans; Dec 13, 2020 at 02:47 PM.
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Last edited by BadAV; Dec 13, 2020 at 02:55 PM.
Thread Starter
Melting Slicks
Joined: Oct 2010
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From: Tollesboro Kentucky
Tried it with 2 different trans tunes and it is still the same.Noticed no difference between the tune from my cam swap when the transmission was tuned also.I installed my old TCM tune from Diablew and it acts the same.Any idea how much RPM change I should see between 5th and 6th with a 2'56 rear end?Looking for ideas and I appreciate the responses
Last edited by jamieo; Dec 13, 2020 at 05:43 PM.
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Tried it with 2 different trans tunes and it is still the same.Noticed no difference between the tune from my cam swap when the transmission was tuned also.I installed my old TCM tune from Diablew and it acts the same.Any idea how much RPM change I should see between 5th and 6th with a 2'56 rear end?Looking for ideas and I appreciate the responses
Are you still running the stock converter?
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Melting Slicks
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From: Tollesboro Kentucky
Yes,I am still using the stock converter.I haven't had any indications of a misfire.No codes and no pending codes that I can find.
Last edited by jamieo; Dec 14, 2020 at 06:54 PM.
Thread Starter
Melting Slicks
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From: Tollesboro Kentucky
Just drove it about 200 miles today.Sometimes it would lock in and sometimes it wouldn't.I did notice that the CEL flashed several times when I first started it but it quit after a few seconds with no more light.Thought maybe I was going to be able to get a misfire code or something but no luck.Codescan was clean.I datalogged with the intune with no luck on a misfire count.It may be time to revisit the tuner who did the cam swap and tune.I may try a new set of wires but the plugs only have about 600 miles on them so I wouldn't think they would be an issue.I will have to see what plugs he used as I have heard several issues with the NGKs.
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Just drove it about 200 miles today.Sometimes it would lock in and sometimes it wouldn't.I did notice that the CEL flashed several times when I first started it but it quit after a few seconds with no more light.Thought maybe I was going to be able to get a misfire code or something but no luck.Codescan was clean.I datalogged with the intune with no luck on a misfire count.It may be time to revisit the tuner who did the cam swap and tune.I may try a new set of wires but the plugs only have about 600 miles on them so I wouldn't think they would be an issue.I will have to see what plugs he used as I have heard several issues with the NGKs.
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Melting Slicks
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From: Tollesboro Kentucky
That is kind of what I expected to find.Odd that no codes are shown but stranger things have happened.Chased an issue similar to this on my supercharged truck.Swapped out the NGK plugs and no issues since.
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I run stock plugs in my 9 second race car and have never had an issue.
Burning Brakes
Joined: Nov 2019
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Regarding the NGK plugs there are loads of counter fit items about. I make sure to buy genuine ones from known good vendors, usually platinum or iridium, and use them on my bikes and cars. Touch wood all fine so far.
I'm curious to know what the issues were, so I can keep an eye out for them.
I'm curious to know what the issues were, so I can keep an eye out for them.
Last edited by gavinfdavies; Dec 19, 2020 at 06:41 PM.