Slipping trans after rebuild.

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BradHanks15

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You should be shifting into 2nd at or before 15mph. Put a bi-directional scan tool on it to see if a shift is being commanded or not. That will at least tell you what the PCM is telling the transmission to do. If it's not shifting, command a shift to see how it reacts.

Another test is to see if it moves forward without a link to the PCM - unplug the large, round case connector from the trans, fire it up and see if it will move on it's own. You'll be in third gear (limp mode) when you do this so dont try to drive it around on the street. You're just looking to isolate the trans from the PCM to see if your 3-4 pack, forward clutch are both working.
 

BradHanks15

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You should be shifting into 2nd at or before 15mph. Put a bi-directional scan tool on it to see if a shift is being commanded or not. That will at least tell you what the PCM is telling the transmission to do. If it's not shifting, command a shift to see how it reacts.

Another test is to see if it moves forward without a link to the PCM - unplug the large, round case connector from the trans, fire it up and see if it will move on it's own. You'll be in third gear (limp mode) when you do this so dont try to drive it around on the street. You're just looking to isolate the trans from the PCM to see if your 3-4 pack, forward clutch are both working.
Update:tried to move it today. Is
Even worse it Barely moves in d now. Was able to command 3rd and it took even more throttle to barely move so it seems like that is working. Couldn’t get to the trans connector without removing exhaust so I’ll just go ahead and pull the trans now.
 

NickTransmissions

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Update:tried to move it today. Is
Even worse it Barely moves in d now. Was able to command 3rd and it took even more throttle to barely move so it seems like that is working. Couldn’t get to the trans connector without removing exhaust so I’ll just go ahead and pull the trans now.

Do a line pressure test before you yank the transmission, if you haven't pulled it already. You need to have a baseline for reference later when you're done with the corrective work.
 

BradHanks15

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Yeah I did already. Couldn’t get the pressure over 80 in reverse or when I commanded more pressure.
I did the forward drum out. Pressure checked okay. Forward clutches are completely smoked. All other clutches look brand new. Do you think this is because of the used torque converter?
 

BradHanks15

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Yeah I did already. Couldn’t get the pressure over 80 in reverse or when I commanded more pressure.
I did the forward drum out. Pressure checked okay. Forward clutches are completely smoked. All other clutches look brand new. Do you think this is because of the used torque converter?
It’s the overrun clutch apologies.
 

NickTransmissions

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You have burnt forward and coast clutches there. You need to find out exactly why they burned so bad before you just put it back together. I say that because it's not typical for you to see this on tear down.

Id start by checking pump working surface clearance and vacuum test the boost and PR valve in the stator support - i show folks how to do that here.

Burnt 3-4s and/or broken sun shell are common, followed by bad/damaged planets (lube restrictions), scorched bands/rev input drum band surfaces (debris in the 3rd acc check ball capsules) and burnt low reverse due to the center seals hardening..

I have a video called "Autopsy on a 4L60E" that had burnt/smoked forwards that looked like those clutches in your pic. I identified the cause once I had all the parts cleaned off and back on the bench for close inspection.

Lastly, please quote my post or mention me @NickTransmissions if you would like me to answer replies as I dont watch any threads...
 

BradHanks15

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You have burnt forward and coast clutches there. You need to find out exactly why they burned so bad before you just put it back together. I say that because it's not typical for you to see this on tear down.

Id start by checking pump working surface clearance and vacuum test the boost and PR valve in the stator support - i show folks how to do that here.

Burnt 3-4s and/or broken sun shell are common, followed by bad/damaged planets (lube restrictions), scorched bands/rev input drum band surfaces (debris in the 3rd acc check ball capsules) and burnt low reverse due to the center seals hardening..

I have a video called "Autopsy on a 4L60E" that had burnt/smoked forwards that looked like those clutches in your pic. I identified the cause once I had all the parts cleaned off and back on the bench for close inspection.

Lastly, please quote my post or mention me @NickTransmissions if you would like me to answer replies as I dont watch any threads...
Thanks I’ll do all of that.
 
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