4L60e Extremely hard shift into drive/reverse (not PCS)
07-12-2018, 07:14 PM
#1
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4L60e Extremely hard shift into drive/reverse (not PCS) I want to ask this community for some help diagnosing a transmission problem. I installed an HD-2 shift kit on a 140k transmission.
Symptoms: Shifting from park or neutral to drive or reverse is so hard that the tires chirp while on the brakes and e-brake on. When putting the car into drive/reverse, the engine revs up about 600 rpm and then dips low when it engages. Performance is great otherwise throughout the other gears.
I have changed the PCS and logged the amperage being commanded to 1.05A, and I have tested the idle PSI to be 55. Looking at the gauge when I put the car into drive, the psi stays at 55 but spikes up much higher a few times for just a fraction of a second. But the psi stays at 55 in drive as well. I then replaced the entire valve body with a stock one from another transmission, which included all the solenoids. The problem is still there.
The only things left modified from the shift kit would be the 1-2 accumulator and the servo. Would a problem with either of these things cause this?
Thank you all in advance for any info you have.
Symptoms: Shifting from park or neutral to drive or reverse is so hard that the tires chirp while on the brakes and e-brake on. When putting the car into drive/reverse, the engine revs up about 600 rpm and then dips low when it engages. Performance is great otherwise throughout the other gears.
I have changed the PCS and logged the amperage being commanded to 1.05A, and I have tested the idle PSI to be 55. Looking at the gauge when I put the car into drive, the psi stays at 55 but spikes up much higher a few times for just a fraction of a second. But the psi stays at 55 in drive as well. I then replaced the entire valve body with a stock one from another transmission, which included all the solenoids. The problem is still there.
The only things left modified from the shift kit would be the 1-2 accumulator and the servo. Would a problem with either of these things cause this?
Thank you all in advance for any info you have.
07-19-2018, 12:52 AM
#3
My car had this exact problem when I first got it. After a post on here 2 years ago I was told to check several items. The throttle position sensor was one of them - and it was proven to be not reading 0% at idle so the PCM was commanding a higher line pressure. My line pressure was over 100psi if I recall. Replacing the TPS mostly cured the issue, but it was still never fully smooth going into drive and sometimes it would still bang into gear - randomly. I took it into the shop and they diagnosed that the forward accumulator piston had been fitted the wrong way around and the forward abuse valve was missing its spring.
These items cured the issue full stop. As you've fitted a HD2 kit (which mine has too) then id guess you may have either forgotten to fit a spring, or fitted something the wrong way in that forward accumulator area of the valve body.
Both of those faults mine had, had been mentioned as prime candidates for the problem by the 2 gents who helped me out in this forum (MrVedit and ClineBarger) and they weren't wrong..
These items cured the issue full stop. As you've fitted a HD2 kit (which mine has too) then id guess you may have either forgotten to fit a spring, or fitted something the wrong way in that forward accumulator area of the valve body.
Both of those faults mine had, had been mentioned as prime candidates for the problem by the 2 gents who helped me out in this forum (MrVedit and ClineBarger) and they weren't wrong..