Torque Converter coming out
05-06-2007, 07:31 AM
#1
Torque Converter coming out
Well I have to pull the transmission out again. 4th time in about a year and half. 
I have a bad slip in 4th gear. Logs as being torque converter slip. I am going to put the stock converter back in to see if it remedies it. I've been researching it for couple months and can find nothing that explains a converter that otherwise works well, slip like this in one gear. Still pulls fine WOT and everywhere else. Only does it 4th gear just as the TCC unlocks and PCM goes to Mode --3---
If the stocker works I will send the TC back and get it refreshed. Might give a Yank converter a try.
Here is a screenshot of the slip logged with HPT.
I have a bad slip in 4th gear. Logs as being torque converter slip. I am going to put the stock converter back in to see if it remedies it. I've been researching it for couple months and can find nothing that explains a converter that otherwise works well, slip like this in one gear. Still pulls fine WOT and everywhere else. Only does it 4th gear just as the TCC unlocks and PCM goes to Mode --3---
If the stocker works I will send the TC back and get it refreshed. Might give a Yank converter a try.
Here is a screenshot of the slip logged with HPT.
05-06-2007, 10:41 AM
#2
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When the PCM goes into "mode --3--" it unlocks the converter, I would manualy lock the converter and see if the slip goes away. have you played with the force motor tables yet? I found I had to turn my line pressure WAY up to get my old converter to work O.K, are there any DTC's?
I know pulling the trans SUCKS big time if you've already done it three or four time lol, but look on the bright side, Your truck will be faster with the stocker anyway.......
I know pulling the trans SUCKS big time if you've already done it three or four time lol, but look on the bright side, Your truck will be faster with the stocker anyway.......
05-06-2007, 11:14 AM
#3
I've done a lot of logging and manually locked the converter. It does not slip when the TCC is applied. In 4th if the TCC unlocks like up a little grade or on a slight decel and enters mode 3 is the only time it does it. It's like a free wheel.. any throttle input then will just slip as far as I would want to mash it. Let off the throttle and let the TCC lock and its solid. It's weird. No DTC's and I am vacuum modulated so no line pressure control via the PCM. I would like to put a line pressure gauge to it but don't have one. Per the logs it is not the tranny slipping, in the log shot posted RPM @ 4276, Tranny input shaft @ 2010 rpm. 2300rpm TC slip. Its either the torque converter or some weird fluid starvation of the converter IMO. Changing out the torque converter will at least point to which.
Yeah it does suck pulling it again. I am going to put it off for a bit. I am tired of crawling around under the dang thing.
You are right. I didn't gain a whole lot with the converter. I'll have to try the track with the stocker before I decide on going back with an aftermarket.
Yeah it does suck pulling it again. I am going to put it off for a bit. I am tired of crawling around under the dang thing.
You are right. I didn't gain a whole lot with the converter. I'll have to try the track with the stocker before I decide on going back with an aftermarket.
05-07-2007, 06:51 PM
#4
Spoke with PI today. I'll be sending the converter back to them. Possibly some vanes bent in either the pump or turbine. Would cause the symtoms. Slightly elevated tranny fluid temps, now stalling to 3000 rpm and not enough umph (hydraulic coupling) to hold in 4th gear.
05-13-2007, 01:36 PM
#7
Well its out. Wearing things out taking them apart. Lost a speed sensor connector clip and forgot to undo the transfer case vent tube and it snapped one of the little tabs on it. Now I'll worry about the little smidge of plastic floating around in the transfer case screwing it up. 
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05-13-2007, 03:36 PM
#8
I would go with wilds suggestions and adjust your lockup pressure before going through all that trouble if you command the tcc silenoid to lock and it stays locked no matter the TPS then its not the clutch its in the tune.
What your describing just sounds like a "loose" stall.
What your describing just sounds like a "loose" stall.
05-13-2007, 04:12 PM
#9
Nothing wrong with the clutch. It is the converter and yeah its a loose converter. So loose it will not hold 4th gear. I never found what rpm it would catch in 4th but its somewhere north of 4500rpm. Didn't do it until recently and I hadn't done anything to the tune transmission related for months. I have played with the tune since but hasn't helped and its getting worse. It has to be fixed.
05-26-2007, 12:14 PM
#10
Got the converter to PI. After opening it up they found nothing physically wrong with it. Long discussion with Jack and he is modifying the stator to tighten it up. Will loose STR down low.... 60' but improved midrange. Couldn't guarantee that it would solve the issue and if not eluded that there was nothing more he could do and suggested I sell it. No definite explanation as to why it worked for months and doesn't now. Maybe TCC clutch material breaking in and now not adding some resistance that it was when new.
I am putting my stock converter back in for awhile. 2 reasons.... 1)to see how it performs at the track, when I put the PI in I don't remember it improving ET's much at all and I didn't get a warm fuzzy that the converter would be fixed and if so for how long? 2) It's taken them to long to turn the darn thing around been out for week and half now. Originally when I spoke with PI. "No problem, we'll have it in and back out the same day"
If the stocker doesn't work like I want. It will be time to give a Yank a try.
I am putting my stock converter back in for awhile. 2 reasons.... 1)to see how it performs at the track, when I put the PI in I don't remember it improving ET's much at all and I didn't get a warm fuzzy that the converter would be fixed and if so for how long? 2) It's taken them to long to turn the darn thing around been out for week and half now. Originally when I spoke with PI. "No problem, we'll have it in and back out the same day"
If the stocker doesn't work like I want. It will be time to give a Yank a try.