4l80E hard shift question
4l80E hard shift question I have purchased a truck recently. it had a motor swap and 4L80E installed.
I am an automatic transmission noob, that is this is the first of 20 plus vehicles I have owned in my life to not be manual, so it is learning time.
Both the motor and trans had been supposedly rebuilt recently and have around 6,500 miles on them. After crawling in and around and seeing the new gaskets and general spotlessness, and fresh looking paint, I am inclined to believe this.
The transmission shifts at part throttle are quite firm. The prior owner was fine with this, but I do not believe it is necessary to have part throttle shifts that pull my foot off the accelerator as this can be adjusted based on conditions, like when in towing mode.
I will be fine with this as well, as long as a future tuner isn't going to point this out as a problem and refuse to tune my vehicle.
The shop that performed the work were good fabricators, but admitted to not being great tuners.
I asked if a shift kit was installed, I was told the trans was a completely stock rebuild (by a trans shop, not him) and he had tried to adjust shift firmness during the tune, but came to the conclusion that the pump pressures had been set high. He mentioned an adjustment screw to turn the pressure down in the pan near the filter.
I have been doing a lot of research on the 4L80E in the last few days, including a 2 plus hour video where someone ran through a complete rebuild of one of these, part by part. I have been learning as much as I can without pulling the pan off. It all seems pretty simple.
I have seen no where to adjust pump pressures, except with a shift kit or electronically with the solenoid. Am I missing something or was this guy mistaken about the whole screw adjustment? Since someone else actually did the work, I am thinking this may have gotten the Transgo shift kit or something like that and he just didn't know.
I am planning on taking this truck to someone with experience to tune the motor and transmission as soon as I make a couple of other changes, might as well do this all at once. Whenever I go to get this tuned, I want any potential hangups corrected ahead of time.
I am an automatic transmission noob, that is this is the first of 20 plus vehicles I have owned in my life to not be manual, so it is learning time.
Both the motor and trans had been supposedly rebuilt recently and have around 6,500 miles on them. After crawling in and around and seeing the new gaskets and general spotlessness, and fresh looking paint, I am inclined to believe this.
The transmission shifts at part throttle are quite firm. The prior owner was fine with this, but I do not believe it is necessary to have part throttle shifts that pull my foot off the accelerator as this can be adjusted based on conditions, like when in towing mode.
I will be fine with this as well, as long as a future tuner isn't going to point this out as a problem and refuse to tune my vehicle. The shop that performed the work were good fabricators, but admitted to not being great tuners.
I asked if a shift kit was installed, I was told the trans was a completely stock rebuild (by a trans shop, not him) and he had tried to adjust shift firmness during the tune, but came to the conclusion that the pump pressures had been set high. He mentioned an adjustment screw to turn the pressure down in the pan near the filter.
I have been doing a lot of research on the 4L80E in the last few days, including a 2 plus hour video where someone ran through a complete rebuild of one of these, part by part. I have been learning as much as I can without pulling the pan off. It all seems pretty simple.
I have seen no where to adjust pump pressures, except with a shift kit or electronically with the solenoid. Am I missing something or was this guy mistaken about the whole screw adjustment? Since someone else actually did the work, I am thinking this may have gotten the Transgo shift kit or something like that and he just didn't know.
I am planning on taking this truck to someone with experience to tune the motor and transmission as soon as I make a couple of other changes, might as well do this all at once. Whenever I go to get this tuned, I want any potential hangups corrected ahead of time.
Last edited by transam1998; Oct 5, 2017 at 10:51 AM.
First thing I would suggest, is getting a gauge on it, and see what the pressure is at idle, in reverse, and in gear at say 2k rpm. This will tell you if someone jacked with the screw pressure.
Forgive me, it's been a long day, and I can't remember the actual name of the part, where the pressure can be changed. Generally, it is frowned upon to do this by most in the trans community. The pressure should be changed by a boost valve, and then in the tune if needed.
Forgive me, it's been a long day, and I can't remember the actual name of the part, where the pressure can be changed. Generally, it is frowned upon to do this by most in the trans community. The pressure should be changed by a boost valve, and then in the tune if needed.
First thing I would suggest, is getting a gauge on it, and see what the pressure is at idle, in reverse, and in gear at say 2k rpm. This will tell you if someone jacked with the screw pressure.
Forgive me, it's been a long day, and I can't remember the actual name of the part, where the pressure can be changed. Generally, it is frowned upon to do this by most in the trans community. The pressure should be changed by a boost valve, and then in the tune if needed.
Forgive me, it's been a long day, and I can't remember the actual name of the part, where the pressure can be changed. Generally, it is frowned upon to do this by most in the trans community. The pressure should be changed by a boost valve, and then in the tune if needed.
The only messing with that pressure piece I may do will be to back it to where it should be, then get the pressures adjusted the right way.