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Lazy Lock-Up??

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Old 12-01-2006, 05:41 PM
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Originally Posted by Ratchthed
I would bet that the PWM is the cause of the symptom you described. But the real question is, does the vehicle have a problem... the simple answer is no in my opinion. You are feeling a Pulse width Modulated converter lock-up and that is not a bad thing at all.
g
It is if it is trying to pulse a clutch that cannot be partially applied. I have heard of many people with aftermarket converters on the stock transmission having problems down the road with the clutch eventually wearing out and not locking anymore. Not once have I seen a TCC failure (actual material worn/broken down) from one of these converters installed on an aftermarket/built transmission that has PWM eliminated, and a shift kit to boost line pressure for a strong TCC apply.

No trans expert, but just something I have noticed
Old 12-03-2006, 02:35 PM
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Originally Posted by BlackHawk T/A
It is if it is trying to pulse a clutch that cannot be partially applied. I have heard of many people with aftermarket converters on the stock transmission having problems down the road with the clutch eventually wearing out and not locking anymore. Not once have I seen a TCC failure (actual material worn/broken down) from one of these converters installed on an aftermarket/built transmission that has PWM eliminated, and a shift kit to boost line pressure for a strong TCC apply.

No trans expert, but just something I have noticed
Interesting observation. My experience tells me that any and all converter clutches can fail and do in all sorts of applications. New or reman parts, PWM or not, high horsepower high torque or bone stock grocery getter minivans.

And yes, we did see much less TCC failure prior to seeing TCC PWM management software. Think about it, if the clutch piston is being fed pressure on a PW then it only stands to reason that the clutch is slipping, and if the clutch is slipping then it is generating heat. If then that clutch is in a car that does not have adequate cooling capabilities then it is going to burn prematurely, simple fact.

I would argue that in the example of a converter only swap, most of the cars did not get a external aftermarket cooler. And those transmissions/converters died because of the excessive heat generated by the new converter being in a stall condition most of the time because it "felt great" to leave it in 3rd gear while cruising.

But conversely, if a bad *** transmission and converter were purchased, then that investment was most likely protected with a much improved cooling system. And that contributed to the longetivety of the combination. Not necesarily the PWM strategy and hydraulics modifications.

I am not arguing the PWM elimination, hydraulics massage issue at all. It is a well known fact that if line pressure is increased then overall durability is improved, on any unit. And it only makes sense that if the converter clutch is not on a PWM but an on/off strategy it will last much much longer.

Again though, I believe the symptoms described in this thread are normal operating conditions for a 4l60E converter lock-up strategy. But, I could be wrong. Just my opinions.
g
Old 12-06-2006, 11:44 AM
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I just installed an SS 4000 in my car with a fresh tranny and it does the eaxact same lazy type lockup described in this thread.. It stays locked though.. Also as I stated earlier in the thread the SS 3800 in my wifes TA does the same thing.. To me this is more of a characteristic of the converter then the tranny..
Old 12-06-2006, 03:55 PM
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Hope your right Joel...One other thing I notice is in the Mornings when I 1st drive the car it Won't lock up right away, Or won't lock at all on a 2 mile stretch. Every time I come home for lunch, go back to work & come home again it locks fine. Very weird. I guess the Trans fluid needs to warm up? My SES light came back on so I am going to see what that code is tonight.
Old 12-06-2006, 04:25 PM
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Originally Posted by Dan
Hope your right Joel...One other thing I notice is in the Mornings when I 1st drive the car it Won't lock up right away, Or won't lock at all on a 2 mile stretch. Every time I come home for lunch, go back to work & come home again it locks fine. Very weird. I guess the Trans fluid needs to warm up? My SES light came back on so I am going to see what that code is tonight.
The TC will not lock until the ECT reaches 160* At lunch time your car is proablly still warm from the morning drive.
Old 12-06-2006, 07:30 PM
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Originally Posted by Dan
Re-setting the PCM did nothing..Here is the whole story...Bought rebuilt Race transmission from reputable shop here in Cali, Guy has built thousands of transmissions, also bought new Yank Converter..I posted on here when I 1st got everything installed that the Converter was locking & unlocking..I had a Vigilante before this with no lock, unlock issues..had a tuner check it out & It seemed we determined that it was in the tune, so he upped the misfire table to max & that cured the problem. NOW about 500 miles later, all of a sudden the converter locks sloppily, I just drove the car & when I am cruising at about 60(Locked) & barely hit the gas it is half locked & unlocked like it's slipping..What do you think? Should I have the tune looked at again? This is not an easy thing for me if I have to yank(no pun intended) that converter out, I have to pay a shop for labor, AGAIN
He's saying that it just started happening after working properly...

If you have a scan tool and a buddy, take a test drive and command the TCC on (both solenoids to ON/100%) and off several times; this overrides what the tune would command, so you should be able to see if there's any difference; if there's no difference, then one of the solenoids could be slow or leaking or partly failing somehow, or the TCC is failing; if there is a difference, then the problem would be in the tune.
Old 12-07-2006, 05:26 AM
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Vacuum Mod will fix you right up
Old 04-30-2007, 10:03 PM
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I understand the TCC PWM tuning described. Any suggestions about what to do with the TCC pressure apply rate?
Old 04-30-2007, 10:39 PM
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Yes, eliminate that function entirely. It serves no purpose in a performance application. Without going into great detail, we use the mods in the Trans Go HD-2 reprogramming kit to do this.

We also remove the check ball from the input shaft if we have the unit on the bench.



back to the original question though.... was this vehicle repaired? If so what did it?

g
Old 05-01-2007, 08:10 AM
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The car was fixed..what an ordeal..The rear planataries melted..The trans shop gave me the safe answer & was not sure why that happened..converter was sent back to Yank & it checked out fine. I think the trans shop just screwed up in my opinion, but It is fine now. The shop kept my $400 core charge, which I thought was a fair deal..Guy drove 160 miles to pick up my car to tow it to his shop, $250 for the converter to be looked at. he had to use another core because it cracked the case. In the end I am happy 4 now, I just hope it lasts a while.
Old 05-01-2007, 03:41 PM
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Sounds like it worked out fine in the long run. Good for you. Sounds like that shop did what they had to in order to make the deal right for both parties... good for them. Thanks for posting that info.

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Old 05-02-2007, 12:18 AM
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Originally Posted by Joel_SS
The TC will not lock until the ECT reaches 160* At lunch time your car is proablly still warm from the morning drive.

whats the ECT?
Old 05-02-2007, 01:25 AM
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PWM should always be eliminated with small diameter converter , Thye just dont have enough area and literally the TC clutch gets fried , We eliminate it in all out units, remove the check ball from the input shaft and enlarge the tcc feed/'release holes
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