New 4L70E went soft
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New 4L70E went soft i rebuilt a 4l70e and installed a new TCI converter. Everything was fine for about 100ish miles, then it felt as if everything started getting softer and softer... HP tuners said zero recorded slips (im not sure if its even capable recording it anyways) Its gotten so soft that just by putting it in gear, the car no longer moves itself with foot off the brake. i dont want to drive it anymore. i ended up installing a new boost valve and changing the fluid after that. and it did help. i was shocked by the clutch material in the pan, i felt that there was alot, but people said to expect alot on a new rebuild?? the fuild was red and unburned, but to me there looked like alottt of clutch, new or not.
so i thought it was "fixed", then after driving it another 50-100miles it got super soft again... so now it sits.
the trans is soft in all gears, reverse included. when you first start the car, i can hear what sounds like the pump whining, then i cant hear it over the exhaust. but the noise comes from the trans for sure...
im putting pressure a gauge on it today and will report back.
other info:
-the pump was not rebuilt (sketchy i know)
-the lip seals in input drum were not replaced (sketchy i know)
-the converter never seemed to stay locked up, even at first. it always seemed to engage and disengage. and it would take a really long time for it to lock up when driving steady on freeway.
-the converter seemed to fit really tight in the pump
-i do not recall input shaft play. what happens when its too tight?
-the filter did seem sort of "loose" in the pump, but i dont recall how tight it was in there to begin with. so maybe its ok
-the EPC and TCC solenoid have NOT been replaced (but other solenoids were)
what else can i do to troubleshoot this?
so i thought it was "fixed", then after driving it another 50-100miles it got super soft again... so now it sits.
the trans is soft in all gears, reverse included. when you first start the car, i can hear what sounds like the pump whining, then i cant hear it over the exhaust. but the noise comes from the trans for sure...
im putting pressure a gauge on it today and will report back.
other info:
-the pump was not rebuilt (sketchy i know)
-the lip seals in input drum were not replaced (sketchy i know)
-the converter never seemed to stay locked up, even at first. it always seemed to engage and disengage. and it would take a really long time for it to lock up when driving steady on freeway.
-the converter seemed to fit really tight in the pump
-i do not recall input shaft play. what happens when its too tight?
-the filter did seem sort of "loose" in the pump, but i dont recall how tight it was in there to begin with. so maybe its ok
-the EPC and TCC solenoid have NOT been replaced (but other solenoids were)
what else can i do to troubleshoot this?
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From: Ann Arbor, MI
Read through this similar thread in which I just posted some diagnostic info on using a pressure gauge:
https://ls1tech.com/forums/automatic...l-failing.html
Report the pressures here and we will go from there.
https://ls1tech.com/forums/automatic...l-failing.html
Report the pressures here and we will go from there.
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when trans is cold, PRND321 are all ~255psi
when trans is 130F:
P ~200psi
R ~200psi
N ~180-220psi
D ~200psi
3 ~200psi
2 ~180psi
with about 1500rpm, all gears would be about 250psi
i checked fluid level once when truck was 'warm', and the fluid level was about 1/4 into the HOT section.
i checked again once trans fluid was 130F, and fluid was 1" over the top of HOT fill line. there was no bubbles or foam on dipstick. (the trans is over filled)
putting the truck in gear, it would want to move on its own.
its a 3200stall converter.
i engaged the lockup clutch, and the truck stalled immediately. so it seems that the clutch/solenoid is 'working'.
its not letting me upload my video
when i first built the trans, i air checked it. all seemed good. and it drove fine. it wasnt until about 100miles or so where it started getting soft.
and for it to be soft in all gears is weird, since i did replace the seals in what i believed was the reverse piston. (thinking out loud here) if i have good line pressure, and new seals in reverse, shouldn't my reverse be as solid as ever?
when trans is 130F:
P ~200psi
R ~200psi
N ~180-220psi
D ~200psi
3 ~200psi
2 ~180psi
with about 1500rpm, all gears would be about 250psi
i checked fluid level once when truck was 'warm', and the fluid level was about 1/4 into the HOT section.
i checked again once trans fluid was 130F, and fluid was 1" over the top of HOT fill line. there was no bubbles or foam on dipstick. (the trans is over filled)
putting the truck in gear, it would want to move on its own.
its a 3200stall converter.
i engaged the lockup clutch, and the truck stalled immediately. so it seems that the clutch/solenoid is 'working'.
its not letting me upload my video
when i first built the trans, i air checked it. all seemed good. and it drove fine. it wasnt until about 100miles or so where it started getting soft.
and for it to be soft in all gears is weird, since i did replace the seals in what i believed was the reverse piston. (thinking out loud here) if i have good line pressure, and new seals in reverse, shouldn't my reverse be as solid as ever?
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I am assuming you have harness unplugged from trans to get those readings? If so the numbers look fine,
To me sounds more like you either have a converter clutch failure assuming all the gears still shift and are not slipping and his is clogging up your filter,
I would pull pan again if you find alot of debris again this would be my guess but unfortunately probably enough damage has been done to require another complete rebuild and clean out
To me sounds more like you either have a converter clutch failure assuming all the gears still shift and are not slipping and his is clogging up your filter,
I would pull pan again if you find alot of debris again this would be my guess but unfortunately probably enough damage has been done to require another complete rebuild and clean out
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I am assuming you have harness unplugged from trans to get those readings? If so the numbers look fine,
To me sounds more like you either have a converter clutch failure assuming all the gears still shift and are not slipping and his is clogging up your filter,
I would pull pan again if you find alot of debris again this would be my guess but unfortunately probably enough damage has been done to require another complete rebuild and clean out
To me sounds more like you either have a converter clutch failure assuming all the gears still shift and are not slipping and his is clogging up your filter,
I would pull pan again if you find alot of debris again this would be my guess but unfortunately probably enough damage has been done to require another complete rebuild and clean out
no everything was plugged in. only thing is that the ecu was probably reset when the battery died. also, i have the adpative shift pressure learn turned off. (i turned it off a long time ago to aid in troubleshooting)
not to say the converter clutch is ok, but when i commanded it on, it engaged quick and stopped the engine. it didnt slip at all. but then again that was with no load on it.
the trans will shift through all the gears. i cant feel it do it. but i can see it on the tach. and like i said, HP tuners said it wasnt slipping... but sometimes the values lie or read zero when its not capable of measuring it. the 1-2 upshift is violent... but also the kit was a 'race' overhaul kit, so some of the modifications were removing the shift dampening. i believe one of the accumulator springs was removed, and all of the wave plates were removed.
the fluid on the dipstick looked brand new. but i know that doesnt say much for what could be left in the pan/filter
right after the rebuild, the shifts were really quick, and 'tight'. there was no hard banging or slamming. you could really feel the shifts, even while just cruising around. Now, i can feel it @ WOT, but cruising you cant fell it but just see the rpms drop with each gear. with the exception of the 1-2slam (which it did not do before)
thinking out loud again, is it possible that its leaking internally, and its commanding max line pressure? or is that commanding it for other reasons? and the 1-2 bang could be from it running max line pressure?
Last edited by jthomas; Feb 19, 2017 at 02:41 PM.
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i dont have a way to look at the adaptive pressure values, only reset or turn off... if i could see how much pressure it was adding or removing, that should tell me if i have an internal leak right? is there a way to view this in HP tuners?
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Those pressures are way high for idle the 1-2-3-od pressures at idle should be 80 to 120 psi depending on how you have PR valve and line set on PCM 200lbs plus pressures should only be seen at wot .
Something no right there, But I would still remove pan and see if its full of crap again as a first move .
Something no right there, But I would still remove pan and see if its full of crap again as a first move .
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Those pressures are way high for idle the 1-2-3-od pressures at idle should be 80 to 120 psi depending on how you have PR valve and line set on PCM 200lbs plus pressures should only be seen at wot .
Something no right there, But I would still remove pan and see if its full of crap again as a first move .
Something no right there, But I would still remove pan and see if its full of crap again as a first move .
anything else i should look for while the pan is off?
when the ECU has been reset, doesnt it run max line pressure until the adaptive pressure has be learned?
the trans pressures in the calibration are still factory. The epc solenoid was never adjusted from where it was originally. ill drain the fluid tomorrow and see whats in the pan.
anything else i should look for while the pan is off?
when the ECU has been reset, doesnt it run max line pressure until the adaptive pressure has be learned?
anything else i should look for while the pan is off?
when the ECU has been reset, doesnt it run max line pressure until the adaptive pressure has be learned?
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The PCM will command max pressure in some cases, including detecting slippage, but then always throws a code.
Did you scan for codes?
People generally complain about super hard 1-2 shifts when the PCM commands max pressure due to a code. You seem to be having the opposite.
The adaptive pressure only changes by a little; your Park/idle pressure is almost 3x normal.
I would check the boost valve; your late model 4L70E uses a shorter boost valve than pre '06.
If someone installed the HD2 kit's boost valve with the "aluminum washer" or the Sonnax 4L60E-LB1 boost valve (instead of the LB2), the installed boost valve is too long and you get too much pressure. This Sonnax page documents the correct lengths and part for the pre-06 and '06+ models:
http://www.sonnax.com/parts/2168-lin...1-instructions
Did you scan for codes?
People generally complain about super hard 1-2 shifts when the PCM commands max pressure due to a code. You seem to be having the opposite.
The adaptive pressure only changes by a little; your Park/idle pressure is almost 3x normal.
I would check the boost valve; your late model 4L70E uses a shorter boost valve than pre '06.
If someone installed the HD2 kit's boost valve with the "aluminum washer" or the Sonnax 4L60E-LB1 boost valve (instead of the LB2), the installed boost valve is too long and you get too much pressure. This Sonnax page documents the correct lengths and part for the pre-06 and '06+ models:
http://www.sonnax.com/parts/2168-lin...1-instructions
Thread Starter
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The PCM will command max pressure in some cases, including detecting slippage, but then always throws a code.
Did you scan for codes?
People generally complain about super hard 1-2 shifts when the PCM commands max pressure due to a code. You seem to be having the opposite.
The adaptive pressure only changes by a little; your Park/idle pressure is almost 3x normal.
I would check the boost valve; your late model 4L70E uses a shorter boost valve than pre '06.
If someone installed the HD2 kit's boost valve with the "aluminum washer" or the Sonnax 4L60E-LB1 boost valve (instead of the LB2), the installed boost valve is too long and you get too much pressure. This Sonnax page documents the correct lengths and part for the pre-06 and '06+ models:
http://www.sonnax.com/parts/2168-lin...1-instructions
Did you scan for codes?
People generally complain about super hard 1-2 shifts when the PCM commands max pressure due to a code. You seem to be having the opposite.
The adaptive pressure only changes by a little; your Park/idle pressure is almost 3x normal.
I would check the boost valve; your late model 4L70E uses a shorter boost valve than pre '06.
If someone installed the HD2 kit's boost valve with the "aluminum washer" or the Sonnax 4L60E-LB1 boost valve (instead of the LB2), the installed boost valve is too long and you get too much pressure. This Sonnax page documents the correct lengths and part for the pre-06 and '06+ models:
http://www.sonnax.com/parts/2168-lin...1-instructions
i do not have any codes.
i was told originally that installing the higher stall converter would put it in limp mode and throw codes for slipping. But..... I never got any.
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okay, i dropped the pan and cut open the filter. it doesnt look good...
there was alot of gold and metallic stuff suspended in the fluid.
all i could think was bushings???
i know when i installed new bushings, they fit kinda tight.
there was alot of gold and metallic stuff suspended in the fluid.
all i could think was bushings???
i know when i installed new bushings, they fit kinda tight.