4l80e Rebuilt w/ Jakes D1 Brake, No reverse, No 3-4 Question
06-23-2016, 07:23 PM
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4l80e Rebuilt w/ Jakes D1 Brake, No reverse, No 3-4 Question So I am by no means a super experienced every day transmission builder. I have put together more than a couple 4l60e's with good success. So I took on to build a 4l80e for my 6.0 upgrade to my s10. I am having some issues and want to hammer them all out... I am slightly reluctant to contact Jakes shop directly yet until I have exhausted all means and done all my tests, as I see some forum posts where he dislikes being bothered by not professional shops. I am just an active duty army Soldier who gets into this stuff and I have been successful doing it myself (machined and built my own 370). Below I will described scenerio
Late model 4l80e core. Working when removed. Filthy fluid. Normal wear. Looks like construction truck.
Did a total refresh. New seals, bushings, clutches, alto red stuff, whole kit. Was very attention focused in the build, measured clearances, pressed bushings, feel like I did a good job. Replaced the two oil feed bolts and torqued them.
I bought a Jakes D1 brake valve body. During my build made the needed changes as per the instructions. Drilled the hole. Tapped the check ball hole and put the plug in it, and so on. My servo pin wasn't long enough so I welded to and ground the tip to achieve a good clearance and good servo action for the low reverse. I omitted the seals on the accumulator piston as instructed.
Then came to the valve body install. The instructions stated to reinstall "these four check *****", which I did. I am just hoping that this is as designed, because from the start, was 8, one plugged, which left three holes open, but I assumed based on removal of accumulator this was why.
Install transmission. Run truck. Fill fluid. Check. Fill. Check. I have a derale +4 QT pan so I am right about 16 QTs right now at the full line.
Here is where the symptoms post-
Reverse- No action. Not even a slip. Not a try (while on the ground... will jack it up later and see if anything off the ground). Scanned the computer, it is activating 1-2 solenoid as it says it should. But no movement in reverse.
Drive- Truck goes in to first. Does not try to shift to second, only a couple times (could be in the tune, I am aware on that part). While in manual first, the truck will engine brake which tells me the band is engaging to some extent.
When I am in Manual one and command one with HPtuners it works fine in first, engine brakes, and is good.
When I am in Manual two, and command two, the truck will shift to second and hold fairly well, but slips upon some throttle and can tell its not working properly.
When I am in manual three, and command three, nothing, upon revving the engine you can feel it engage back in second upon higher rpms.
D when I command four, no change, same as third.
If I go from manual 2 to manual 1 the trans binds like Jakes said it would.
In manual one if i ground out the 2-3 solenoid to activate brake no effect. If I activate second gear in hptuners while in manual one, I get a slight hold until about 2000 RPMS (converter is 4000 stall North Texas Converter).
I have yet to put the manual pressure gauge in trans. I will do this tomorrow. Below I will conclude my thoughts.
So I assume my low rev band is working which eliminates the typical pin length answer. I would assume direct clutch, but since second is slipping I think of line pressure issues. I am concerned about only placing four check ***** back in the trans. The fluid isn't burnt at this point, and is showing full. I have hptuners and have been scanning and playing with it with no end result. Looking for some advice or maybe observations, something I am missing. Like I said I am not a pro but I am very meticulous and spent a lot of time ensuring this was correct (so I thought). Any help is appreciated.
Late model 4l80e core. Working when removed. Filthy fluid. Normal wear. Looks like construction truck.
Did a total refresh. New seals, bushings, clutches, alto red stuff, whole kit. Was very attention focused in the build, measured clearances, pressed bushings, feel like I did a good job. Replaced the two oil feed bolts and torqued them.
I bought a Jakes D1 brake valve body. During my build made the needed changes as per the instructions. Drilled the hole. Tapped the check ball hole and put the plug in it, and so on. My servo pin wasn't long enough so I welded to and ground the tip to achieve a good clearance and good servo action for the low reverse. I omitted the seals on the accumulator piston as instructed.
Then came to the valve body install. The instructions stated to reinstall "these four check *****", which I did. I am just hoping that this is as designed, because from the start, was 8, one plugged, which left three holes open, but I assumed based on removal of accumulator this was why.
Install transmission. Run truck. Fill fluid. Check. Fill. Check. I have a derale +4 QT pan so I am right about 16 QTs right now at the full line.
Here is where the symptoms post-
Reverse- No action. Not even a slip. Not a try (while on the ground... will jack it up later and see if anything off the ground). Scanned the computer, it is activating 1-2 solenoid as it says it should. But no movement in reverse.
Drive- Truck goes in to first. Does not try to shift to second, only a couple times (could be in the tune, I am aware on that part). While in manual first, the truck will engine brake which tells me the band is engaging to some extent.
When I am in Manual one and command one with HPtuners it works fine in first, engine brakes, and is good.
When I am in Manual two, and command two, the truck will shift to second and hold fairly well, but slips upon some throttle and can tell its not working properly.
When I am in manual three, and command three, nothing, upon revving the engine you can feel it engage back in second upon higher rpms.
D when I command four, no change, same as third.
If I go from manual 2 to manual 1 the trans binds like Jakes said it would.
In manual one if i ground out the 2-3 solenoid to activate brake no effect. If I activate second gear in hptuners while in manual one, I get a slight hold until about 2000 RPMS (converter is 4000 stall North Texas Converter).
I have yet to put the manual pressure gauge in trans. I will do this tomorrow. Below I will conclude my thoughts.
So I assume my low rev band is working which eliminates the typical pin length answer. I would assume direct clutch, but since second is slipping I think of line pressure issues. I am concerned about only placing four check ***** back in the trans. The fluid isn't burnt at this point, and is showing full. I have hptuners and have been scanning and playing with it with no end result. Looking for some advice or maybe observations, something I am missing. Like I said I am not a pro but I am very meticulous and spent a lot of time ensuring this was correct (so I thought). Any help is appreciated.
06-23-2016, 07:29 PM
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Ahh and to answer a few more questions. Removed harness. No change. Felt like it was in first. No reverse. I did properly repin the trans harness and added the new speed sensor to the front of trans. Repinned PCM harness. Also switched to a 2002 chevy 2500 tune in HP tuners and copied all of my data instead of segmenting as my original tune was 1999 1500 chevy and wasn't compatible with 4l80e so hptuners told me.
06-23-2016, 09:03 PM
#3
No 3rd and no reverse is a good indicator your issue is with the direct circuit.
A pressure test is going to give you the needed information to do further diagnosis.
Reverse doesn't require any electrical input, so solenoid state is not important.
Many novices aren't willing to do basic tests. Without them diagnosis becomes a guessing game that consumes a great amount of time.
My builders know I'm going to want to see pressures before I try to diagnose anything. I expect the same of a DIY builder.
A pressure test is going to give you the needed information to do further diagnosis.
Reverse doesn't require any electrical input, so solenoid state is not important.
Many novices aren't willing to do basic tests. Without them diagnosis becomes a guessing game that consumes a great amount of time.
My builders know I'm going to want to see pressures before I try to diagnose anything. I expect the same of a DIY builder.
06-23-2016, 09:16 PM
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Jake,
I appreciate the response. I will return with pressures tomorrow. I could very much agree its something in direct circuit. I appreciate your time sir.
I appreciate the response. I will return with pressures tomorrow. I could very much agree its something in direct circuit. I appreciate your time sir.
06-25-2016, 12:10 PM
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Pressure Jake, so I put my pressure tester on the transmission to find out that these things make a lot more pressure than my gauge was designed for (140# gauge). But I did manage to do some diagnostic when I got the transmission temperature up to 160 degrees. In reverse, the pressure drops to between 80-90. Back to neutral it climbs back to burying the gauge. In D, 1st gear buries the gauge. When I command third via hptuners the pressure drops below 100, and the same with fourth. Anytime I command open the 2-3 solenoid, I see pressure drops to the same level. These are all taken at idle. I assume this indicates I have trouble in my direct clutch circuit as you mentioned. Do you think it could involve the sealing rings on the center support? This is what I conclude to be failing. Would this also be the reason why second isn't holding as it should?
Last edited by Speedracer2j; 06-25-2016 at 01:54 PM.
