4l80e feels like its slipping
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TECH Apprentice
Joined: Sep 2012
Posts: 347
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From: Tucson, AZ
4l80e feels like its slipping I have been doing some test drives in my L33/4l80e swapped 65 Nova. I rebuilt and modified the 4l80e with a lot of help from this site. It also has a 3500 rpm converter from Jakes Performance. I am controlling the transmission with Holley Terminator Max X
Here is the link to the original 4l80e build thread: https://ls1tech.com/forums/automatic...e-we-go-8.html
Here are the high points:-1994 Core
-All new BW HE Frictions
-Jakes Performance Recalibration kit
-All new seals/bushings
-Rollerized output
-HD Intermediate snap ring
-Dual Feed Directs
-TH400 style Direct Clutch piston(from CK Performance, milled to fit)
-3-4 Accumulator delete
-Bonded steel forward apply piston
-New reaction carrier sprag
-New Boost Valve kit
-TCC Regulator kit
It seems to be slipping and is also very soft shifting, even from Park to Reverse. I know some of this may be the initial tune file, but i think it is more than that. I am waiting on a pressure transducer in the mail to log pressures. Before I installed the pan, i was sure to adjust the braided dipstick to be sure it was set at the right height for proper fluid level. It looked to be about a half quart low when I measured it after running for a few minutes before my drive. I went on a 15 minute drive and did some datalogging to try to see what is going on. When I got back and parked it, I went to check the transmission fluid level with the car running to see exactly where it was at warm. When I pulled the dipstick out , ATF erupted out of the dipstick tube and sprayed all over the car!
What else should I check before I get the pressure transducer? I attached some of the data logs from the drives I took. Thanks in advance for any help or advice!
Data Log 1
Data Log 2
Here is the link to the original 4l80e build thread: https://ls1tech.com/forums/automatic...e-we-go-8.html
Here are the high points:-1994 Core
-All new BW HE Frictions
-Jakes Performance Recalibration kit
-All new seals/bushings
-Rollerized output
-HD Intermediate snap ring
-Dual Feed Directs
-TH400 style Direct Clutch piston(from CK Performance, milled to fit)
-3-4 Accumulator delete
-Bonded steel forward apply piston
-New reaction carrier sprag
-New Boost Valve kit
-TCC Regulator kit
It seems to be slipping and is also very soft shifting, even from Park to Reverse. I know some of this may be the initial tune file, but i think it is more than that. I am waiting on a pressure transducer in the mail to log pressures. Before I installed the pan, i was sure to adjust the braided dipstick to be sure it was set at the right height for proper fluid level. It looked to be about a half quart low when I measured it after running for a few minutes before my drive. I went on a 15 minute drive and did some datalogging to try to see what is going on. When I got back and parked it, I went to check the transmission fluid level with the car running to see exactly where it was at warm. When I pulled the dipstick out , ATF erupted out of the dipstick tube and sprayed all over the car!
What else should I check before I get the pressure transducer? I attached some of the data logs from the drives I took. Thanks in advance for any help or advice!
Data Log 1
Data Log 2
TECH Junkie
Joined: Jun 2008
Posts: 3,203
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From: Nitro Alley
I did NOT look at your Logs...
If pressures are good, but you have slipping in reverse and Third/ Fourth...
Your Direct Piston may be too short/ shallow in the Drum...
Allowing a Steel Plate to drop into a groove above the Piston, partially locking the Piston in the Bore (not applying the Clutch Pack very much).
If pressures are good, but you have slipping in reverse and Third/ Fourth...
Your Direct Piston may be too short/ shallow in the Drum...
Allowing a Steel Plate to drop into a groove above the Piston, partially locking the Piston in the Bore (not applying the Clutch Pack very much).
Thread Starter
TECH Apprentice
Joined: Sep 2012
Posts: 347
Likes: 66
From: Tucson, AZ
Thank you. Reverse doesn't seem to slip. Definitely in 1-2, and less in 3-4
Any thoughts on what would cause the fluid to blast out of the dipstick like that? I have 2 trans coolers and the temp didn't get over 180F. I have added about 8 quarts since startup.
Any thoughts on what would cause the fluid to blast out of the dipstick like that? I have 2 trans coolers and the temp didn't get over 180F. I have added about 8 quarts since startup.
Last edited by Novapat67; Dec 5, 2022 at 07:56 AM.
Thread Starter
TECH Apprentice
Joined: Sep 2012
Posts: 347
Likes: 66
From: Tucson, AZ
Sorry that wasn't worded well at all! I added 8 quarts to start it and then have added 8 more. I saw a few different places recommended starting it was around 8 quarts. Filling with this braided dipstick sucks and I spilled a bunch. I also had to tighten some fittings on the coolers that were leaking. I also needed a different sized o-ring on the dipstick as that was leaking as well. Regular first time start up stuff.
All that being said, it was reading a quart low on the dipstick after running for a few minutes with the fluid temp around 105F. I calibrated the dipstick with "Full" being about 1/4" above the pan rail.
All that being said, it was reading a quart low on the dipstick after running for a few minutes with the fluid temp around 105F. I calibrated the dipstick with "Full" being about 1/4" above the pan rail.
Thread Starter
TECH Apprentice
Joined: Sep 2012
Posts: 347
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From: Tucson, AZ
Thanks for your help. I drilled all 3 of the separator plate holes to 0.125". Below are images of the curves in terminator. My pressure transducer and cable is supposed to arrive today, so as soon as I get that hooked up, I can take a drive and log some pressures. Still weirded out about the fluid blasting out of the dipstick.
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Fluid blasting out of dipstick - Nothing is in That position that would spray pressure. I would check that the vent tube and anything hooked to it is open. Really if you have enough pressure to come out dipstick in case it should be spraying out vent tube too, So I would suspect it or something hooked to it is blocked.
Frank@PerformaBuilt
Frank@PerformaBuilt
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TECH Apprentice
Joined: Sep 2012
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From: Tucson, AZ
Originally Posted by performabuilt
Fluid blasting out of dipstick - Nothing is in That position that would spray pressure. I would check that the vent tube and anything hooked to it is open. Really if you have enough pressure to come out dipstick in case it should be spraying out vent tube too, So I would suspect it or something hooked to it is blocked.
Frank@PerformaBuilt
Frank@PerformaBuilt
Yes, sounds like it is blocked . This too can cause a host of other issues so defiantly should be addressed.
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Frank@Performabuilt
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Not sure if that would have anything to do with the slipping you are experiencing though. ?
Thread Starter
TECH Apprentice
Joined: Sep 2012
Posts: 347
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From: Tucson, AZ
Did you check that vent hole/tube when you were installing the pump? The 4L80e that I rebuilt had that hole filled nearly or completely clogged with corrosion. It's the hole next to the pump bolt threaded holes. I used a drill bit to clear it out and blew it out with compressed air. Maybe try sticking a wire or something to the vent, then suck it out with a vacuum?
Not sure if that would have anything to do with the slipping you are experiencing though. ?
Not sure if that would have anything to do with the slipping you are experiencing though. ?
TECH Apprentice
Joined: Aug 2018
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You aren't by any chance overheating the fluid, are you? Do you have a transmission temperature guage?
Thread Starter
TECH Apprentice
Joined: Sep 2012
Posts: 347
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From: Tucson, AZ
BTW, what hose do you have connected to the vent tube? The early transmissions had a hose to went down to the passenger side. Later transmissions added a breather to went to the top bell housing and the tube runs down the driver side. I honestly don't know how that all works.
You aren't by any chance overheating the fluid, are you? Do you have a transmission temperature guage?
You aren't by any chance overheating the fluid, are you? Do you have a transmission temperature guage?
Thread Starter
TECH Apprentice
Joined: Sep 2012
Posts: 347
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From: Tucson, AZ
I got the vent tube clear I think. I was able to run a wire through it and when I hit it with pressurized air, it pushed fluid out of the dipstick so something is getting through.
I got the pressure transducer hooked up and want to do some tests.
What tests would be the most helpful in diagnosing this slipping?
I got the pressure transducer hooked up and want to do some tests.
What tests would be the most helpful in diagnosing this slipping?
just start with the pressures in each lever range with the fluid hot ~150 or so. write down the pressure in each range at idle and at 2000rpm (foot braking in the R, D4, 3, 2, 1 ranges)
Thread Starter
TECH Apprentice
Joined: Sep 2012
Posts: 347
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From: Tucson, AZ
Thanks! Just fyi, my column shifter only has enough travel to go down to 2. Also, I just noticed with the holley terminator, i cant really rev the engine while i have the brake pedal depressed. Good thing i have a line lock!
Here is what ive got so far witht the fluid temp at 150F:
At Idle:
P - 75
R - 118
4 - 75
3 - 75
2 - 75
At 2000rpm:
P - 105
R - 185
4 - 125
3 - 125
2 - 125
Here is what ive got so far witht the fluid temp at 150F:
At Idle:
P - 75
R - 118
4 - 75
3 - 75
2 - 75
At 2000rpm:
P - 105
R - 185
4 - 125
3 - 125
2 - 125