Subscribed. Having TCC lock/unlock at steady throttle. Tried the Transgo shift kit, didn't work. Just installed a fixall TCC valve with the o-rings, and eliminates the PWM, haven't had a chance to test drive yet. Really not wanting to tear into the transmission if this doesn't fix it.
A lot of things can cause lock up issues. Are you getting the 1870 code? Whether or not that valve fixes your problem it needed to be blocked anyway. In the long run it will help your torque converter.
@@CurmudgeonTransmission , Yes, P1870 code. First two short test drives it would not even try to go into lockup, but the constant lock/unlock fluctuation had stopped. By the next test drive it tried to go into lockup sporadically, but it was really hard to tell, still slipping quite a bit. Next day I went for another drive and it began to lock with some authority, as I assume it's supposed to without PWM, the logger was showing no more than 20rpm slip. Not sure why it took it some time to start working, but just towed around 3,500# or more without an issue. Still a little early to tell, but so far, the fixall valve seems to be working where the Transgo valve did not. The Fixall valve has o-rings, the Transgo kit does not, FWIW.
I should also mention after clearing the codes, P1870 popped back up, I unplugged the battery at some point, but after the drive with the solid TCC lock, the P1870 went away on its own, and is still gone after several drive cycles.
My transmission threw the P1870 code on a normal 60mile drive. During rain i get the rough 1 to 2 shift. Im easy on it. To not tear anything up. Cruise actually accelerates harder than I do. Otherwise, its fine. I do have 221k miles on my firebird though.
That is a lot of miles. Still, may get by with blocking the valve in the valve body that I show. Don't continue to drive it a lot, especially long trips with the code set. It puts the transmission in a high line pressure mode to try to keep the clutch from slipping. While it is good for the short term to get you home, it can actually cause damage over time. That is why your shifts are firm.
Bonjiur, j'ai le même problème sur ma Corvette C5 1999, j'ai fait changé le plateau complet avec les électrovannes, mais j'ai toujours le code P1870 et les a-coups entre la première et la deuxième vitesse après avoir roulé un moment sur une voie rapide...Je viens de remarquer qu si j'efface le code en roulant, je n'ai plus le problème d'a-coups entre la première et la deuxième vitesse ! merci
Are these the only 3 possible reasons for tge po1870 and rough 1 to 2 shift only? I was about to replace the tcc solenoid and 1 2 actuator? Other guys had me convinced?🤞 Thank you!
1870 is a generic slip code. Anything that is slipping can give the code. It is usually the torque converter slipping though. The main cause is the valve in the valve body that I block from being able to stroke. The others are secondary causes. Hopefully you have not done too much damage to the clutch in the converter and you can just do these fixes. You will need to clear the codes or it will still shift hard after the repair. It is shifting hard because it raises line pressure trying to keep the slip from happening.
@@CurmudgeonTransmission Thanks soooo much! Let me ask... I've just been clearing the code and the result is the same each time wich is no slip! It only occurs after a long trip! Would this be an indication of anything? No metal,clean tranny fluid,shifts good until the code pops on? As strange as it sounds some people are swearing that a throttle body positioning sensor solved this for them!? Thank you!🙏
Converter clutch signal valve. If you don't want to block it with check balls or spring depending on which year you have like I show in the valve body, this place sells a valve you put in the place of the factory one. I just block it myself. www.teckpak-fitzall.com/datasheets/A74741CBs.jpg
it says the P1870 can be triggered by dirty tranny fluid. is that true? is it worth trying that before anything else? It seems like the P1870 code is a lot more serious and changing fluid won't fix it . I am having similar problems as others , hard shift 1rst to 2nd, but not all the time. (rarely actually) but everytime its done that, the p1870 code pops up soon afterwards
Where did you read that? Not that I know of. The valve bore is probably worn out. Block that valve like I show. Pull the filter out of the snout of the lock up solenoid while you are there. Go ahead and service the filter and fluid also. I bet your problem goes away.
I have some strange P1870 code on my 1999 PWM 4L60E and wonder if you can help with some advice. My truck is a freeway commuter vehicle. The P1970 problem has arrived from zero problem one day to the 100% problem next day and reliably always comes back after clearing the code. I’m already on the second AC-Delco Reman Valve Body, new selector plate gaskets, I pressure checked the TCC solenoid, I installed a new harness with incl. new TCC solenoid and installed even a new Sonax TCC Apply Valve, but no luck. Even after P1870 code cleared AND with lockup showing enabled on Scantool AND with PWM Duty Cycle showing 96% AND with the Scantool’s TCC-on command, the result is still that reliably ZERO lockup is EVER achieved. However, I’m able to achieve full lock up if I block the TCC Reg. Valve Bore with a stronger spring for Full Line Pressure. THEN, in that case 0 slip is shown on the scan tool upon lockup and the transmission works and shifts perfectly. I read somewhere that the Rear Stator Support Bushing might be out. Would you say this could be my problem?
I always block the valve like I show in the video, biggest problem with this unit. I always put a new pump bushing, rear case and both stator bushings in these units no matter what they look like. Look real close just above the rear stator bushing and make sure that the stator is not ring cut, it will do it towards the pan where all the weight was sitting. Odds are if you had the code long enough you have already damaged the torque converter. Since you said you can block the valve and have zero slip you MAY be ok. Even if I had a brand new valve body I would block that valve.
@@Tom-oz4pm Yes. Problem turned out to be the ECM. It took me about 5 months of changing parts and testing and frustration. I worked on/off, sometimes I just had to take time off from it. All the experts told me I needed a new tranny, but tranny was shifting perfect in low speeds until the ECM recognized too much slip during TCC apply and turned-on high-pressure mode. At one point I started suspecting I have an electrical problem. This is where things started getting interesting. I had a spare ECM with the whole time, some day I just swapped it and the problem disappeared. I think many people who block the valve may have this issue. I tried blocking the valve as well, but decided not even to test it, due to all the rubber debris of the part that becomes lose during installation. Hence, I don’t recommend blocking.
Subscribed. Having TCC lock/unlock at steady throttle. Tried the Transgo shift kit, didn't work. Just installed a fixall TCC valve with the o-rings, and eliminates the PWM, haven't had a chance to test drive yet. Really not wanting to tear into the transmission if this doesn't fix it.
A lot of things can cause lock up issues. Are you getting the 1870 code? Whether or not that valve fixes your problem it needed to be blocked anyway. In the long run it will help your torque converter.
@@CurmudgeonTransmission , Yes, P1870 code. First two short test drives it would not even try to go into lockup, but the constant lock/unlock fluctuation had stopped. By the next test drive it tried to go into lockup sporadically, but it was really hard to tell, still slipping quite a bit. Next day I went for another drive and it began to lock with some authority, as I assume it's supposed to without PWM, the logger was showing no more than 20rpm slip. Not sure why it took it some time to start working, but just towed around 3,500# or more without an issue. Still a little early to tell, but so far, the fixall valve seems to be working where the Transgo valve did not. The Fixall valve has o-rings, the Transgo kit does not, FWIW.
I should also mention after clearing the codes, P1870 popped back up, I unplugged the battery at some point, but after the drive with the solid TCC lock, the P1870 went away on its own, and is still gone after several drive cycles.
@@mikew8734 Should take care of the problem unless it has already done too much damage to the torque converter.
Yes lock up is going to be firmer as it is now an on/off setup instead of gradually applying and always having a slight slip.
My transmission threw the P1870 code on a normal 60mile drive. During rain i get the rough 1 to 2 shift. Im easy on it. To not tear anything up. Cruise actually accelerates harder than I do. Otherwise, its fine. I do have 221k miles on my firebird though.
That is a lot of miles. Still, may get by with blocking the valve in the valve body that I show. Don't continue to drive it a lot, especially long trips with the code set. It puts the transmission in a high line pressure mode to try to keep the clutch from slipping. While it is good for the short term to get you home, it can actually cause damage over time. That is why your shifts are firm.
Awesome Video!! I watch all your vids. A wellspring of info. I am a subscriber!
Thank you, I appreciate it.
Bonjiur, j'ai le même problème sur ma Corvette C5 1999, j'ai fait changé le plateau complet avec les électrovannes, mais j'ai toujours le code P1870 et les a-coups entre la première et la deuxième vitesse après avoir roulé un moment sur une voie rapide...Je viens de remarquer qu si j'efface le code en roulant, je n'ai plus le problème d'a-coups entre la première et la deuxième vitesse ! merci
1870 is a generic slip code. It is usually caused by what is listed here but can be anything in the transmission that is slipping.
Are these the only 3 possible reasons for tge po1870 and rough 1 to 2 shift only? I was about to replace the tcc solenoid and 1 2 actuator? Other guys had me convinced?🤞 Thank you!
1870 is a generic slip code. Anything that is slipping can give the code. It is usually the torque converter slipping though. The main cause is the valve in the valve body that I block from being able to stroke. The others are secondary causes. Hopefully you have not done too much damage to the clutch in the converter and you can just do these fixes. You will need to clear the codes or it will still shift hard after the repair. It is shifting hard because it raises line pressure trying to keep the slip from happening.
@@CurmudgeonTransmission Thanks soooo much! Let me ask... I've just been clearing the code and the result is the same each time wich is no slip! It only occurs after a long trip! Would this be an indication of anything? No metal,clean tranny fluid,shifts good until the code pops on? As strange as it sounds some people are swearing that a throttle body positioning sensor solved this for them!? Thank you!🙏
@@michaeldennis3240 block that valve in the valve body. Bet your problem goes away.
@@CurmudgeonTransmission Just to clarify we are talking tcc valve right? Block or replace it right? Thanks!🤙
Converter clutch signal valve. If you don't want to block it with check balls or spring depending on which year you have like I show in the valve body, this place sells a valve you put in the place of the factory one. I just block it myself. www.teckpak-fitzall.com/datasheets/A74741CBs.jpg
it says the P1870 can be triggered by dirty tranny fluid. is that true? is it worth trying that before anything else? It seems like the P1870 code is a lot more serious and changing fluid won't fix it .
I am having similar problems as others , hard shift 1rst to 2nd, but not all the time. (rarely actually) but everytime its done that, the p1870 code pops up soon afterwards
Where did you read that? Not that I know of. The valve bore is probably worn out. Block that valve like I show. Pull the filter out of the snout of the lock up solenoid while you are there. Go ahead and service the filter and fluid also. I bet your problem goes away.
@@CurmudgeonTransmission how hard is it to do what you did ? do you have to drop the transmission ?
@@titoqwentezproductionz3406 No. You only need to pull the valve body off.. Mechanically inclined, couple of hours.
@@CurmudgeonTransmission ok thanks I will do more research , appreciate the help
When reinstalling valve body it saves alot of time by reinstalling keepers facing down@CurmudgeonTransmission
Size does matter
I have some strange P1870 code on my 1999 PWM 4L60E and wonder if you can help with some advice.
My truck is a freeway commuter vehicle. The P1970 problem has arrived from zero problem one day to the 100% problem next day and reliably always comes back after clearing the code.
I’m already on the second AC-Delco Reman Valve Body, new selector plate gaskets, I pressure checked the TCC solenoid, I installed a new harness with incl. new TCC solenoid and installed even a new Sonax TCC Apply Valve, but no luck.
Even after P1870 code cleared AND with lockup showing enabled on Scantool AND with PWM Duty Cycle showing 96% AND with the Scantool’s TCC-on command, the result is still that reliably ZERO lockup is EVER achieved.
However, I’m able to achieve full lock up if I block the TCC Reg. Valve Bore with a stronger spring for Full Line Pressure. THEN, in that case 0 slip is shown on the scan tool upon lockup and the transmission works and shifts perfectly.
I read somewhere that the Rear Stator Support Bushing might be out. Would you say this could be my problem?
I always block the valve like I show in the video, biggest problem with this unit. I always put a new pump bushing, rear case and both stator bushings in these units no matter what they look like. Look real close just above the rear stator bushing and make sure that the stator is not ring cut, it will do it towards the pan where all the weight was sitting. Odds are if you had the code long enough you have already damaged the torque converter. Since you said you can block the valve and have zero slip you MAY be ok. Even if I had a brand new valve body I would block that valve.
@@CurmudgeonTransmission Many thanks for your helpful response and taking the time!
Your welcome.
Get it fixed?
@@Tom-oz4pm Yes. Problem turned out to be the ECM. It took me about 5 months of changing parts and testing and frustration. I worked on/off, sometimes I just had to take time off from it. All the experts told me I needed a new tranny, but tranny was shifting perfect in low speeds until the ECM recognized too much slip during TCC apply and turned-on high-pressure mode. At one point I started suspecting I have an electrical problem. This is where things started getting interesting. I had a spare ECM with the whole time, some day I just swapped it and the problem disappeared. I think many people who block the valve may have this issue. I tried blocking the valve as well, but decided not even to test it, due to all the rubber debris of the part that becomes lose during installation. Hence, I don’t recommend blocking.