3-4 harsh shift 4l80e

[AuroraGirl]

This is for my 2005 with 6.0 but has anyone had any experience with the 3-4 shift being harsh? I expect the shift to be harsher under a situation such as WOT and letting off the throttle (letting it shift up to 4) but if i take off from a stop and accelerate with 25-50% throttle till it wants to shift to 4 it usually is harsh. warmed up and cold. It still has the TAP values from my step dad owning it (transmission adaptive pressures) and I was going to throw my scan tool on it and clear it so it learns my throttle usage. Maybe he had a lead foot? all other shifts appear fine including downshifts while stabbing the throttle (such as to pass)

I was wondering if anyone with 4l80e experience have had this or can say if its characteristic? Since gmt400 came with 4l80e's in 1991 I put it here lol

Its a 2005 2500hd with 4l80e, lg4(6.0), and np263hd transfer case, and 11.5" aam.

I have been driving it for about a month now and I havent reset the battery or the TAPs so thats why I mentioned I will try clearing them and see. it did have a recent trans service before it came to me (TAPs should be reset after trans service) I just wouldnt expect it to be such an aggressive shift especially with low throttle input. Lower than 25% seems to soften it but it takes a metaphorical minute to get to that speed at that throttle input

 

[NickTransmissions]

This is for my 2005 with 6.0 but has anyone had any experience with the 3-4 shift being harsh? I expect the shift to be harsher under a situation such as WOT and letting off the throttle (letting it shift up to 4) but if i take off from a stop and accelerate with 25-50% throttle till it wants to shift to 4 it usually is harsh. warmed up and cold. It still has the TAP values from my step dad owning it (transmission adaptive pressures) and I was going to throw my scan tool on it and clear it so it learns my throttle usage. Maybe he had a lead foot? all other shifts appear fine including downshifts while stabbing the throttle (such as to pass)

I was wondering if anyone with 4l80e experience have had this or can say if its characteristic? Since gmt400 came with 4l80e's in 1991 I put it here lol

Its a 2005 2500hd with 4l80e, lg4(6.0), and np263hd transfer case, and 11.5" aam.

I have been driving it for about a month now and I havent reset the battery or the TAPs so thats why I mentioned I will try clearing them and see. it did have a recent trans service before it came to me (TAPs should be reset after trans service) I just wouldnt expect it to be such an aggressive shift especially with low throttle input. Lower than 25% seems to soften it but it takes a metaphorical minute to get to that speed at that throttle input

Check for codes, issues with other sensors like the throttle pos sensor, MAF or equivalent and clear the adapts as a first step. If that still makes no difference, drop the pan and remove the valve body. Unbolt the accumulator housing and see if you have a broken 3-4 acc spring...also check the 3-4 shift valve for drag. While it's apart, Id install a Sonnax TCC valve, 1-2/2-3 shift valve spring kit and a Central Valve Bodies drop in oversized AFL valve. Those will address common valve body related issues with the 4L80E.

Note that when you drop the valve body, there will be some check balls that will fall out so you'll need to use assembly lube or petroleum jelly to hold in place for reinstallation of the valve body.

Let me know if you plan on doing this and ill link my 4L80E rebuild video here that covers valve body installation.

 

[AuroraGirl]

Probably not for a while, but that does bring up a good point. Im not opposed to dropping the pan probably come spring or warmer(its getting cold now) and are there any quality of life changes that can be done? Im pretty acquainted with the 4t65e and what kinds of things help that especially "while in there"
Removing the valve body is definitely not something i have done, but to my understanding its very simple when you get down to it? On a transaxle its positioned in the side cover, so much more involved job.

Also, I notice when I drive my 15-30 minute drives to work, the trans fluid gets passed the first mark of 150 but it doesnt get close to 200, so is it possible its running cold? Should I put some cardboard partially in front of the trans cooler (im just assuming it has an auxillary cooler in front of the radiator)

 

[Pinger]

I had harsh up-shifts on my 4L-80E when the fuse for the MAF sensor was missing.

 

[NickTransmissions]

Probably not for a while, but that does bring up a good point. Im not opposed to dropping the pan probably come spring or warmer(its getting cold now) and are there any quality of life changes that can be done? Im pretty acquainted with the 4t65e and what kinds of things help that especially "while in there"
Removing the valve body is definitely not something i have done, but to my understanding its very simple when you get down to it? On a transaxle its positioned in the side cover, so much more involved job.

Also, I notice when I drive my 15-30 minute drives to work, the trans fluid gets passed the first mark of 150 but it doesnt get close to 200, so is it possible its running cold? Should I put some cardboard partially in front of the trans cooler (im just assuming it has an auxillary cooler in front of the radiator)

Quality of life changes? What do you mean?

The recommendations i made re the valve body (and would also buy all new solenoids/harness if they havent ever been replaced plus a new filter and pan gasket) are all the things I would do and ive built hundreds of those things over the years...

And no to your second question - your trans temp is exactly where it should be. Dont fix what isnt broken.

ETA: Hook up a bidirectional scan tool, take it for a test drive with all the transmission and engine live data streams displayed on the screen. Pay close attention to see if anything unusual appears when the transmission shifts from 3rd gear to 4th gear (shift speed, for example). TTC duty cycle/efficiency is another id look at).

 

[AuroraGirl]

Quality of life changes? What do you mean?

The recommendations i made re the valve body (and would also buy all new solenoids/harness if they havent ever been replaced plus a new filter and pan gasket) are all the things I would do and ive built hundreds of those things over the years...

And no to your second question - your trans temp is exactly where it should be. Dont fix what isnt broken.

ETA: Hook up a bidirectional scan tool, take it for a test drive with all the transmission and engine live data streams displayed on the screen. Pay close attention to see if anything unusual appears when the transmission shifts from 3rd gear to 4th gear (shift speed, for example). TTC duty cycle/efficiency is another id look at).

by quality of life, as example, on a 4t65e, is doing a TSB to change a pan magnet and put two in (vs gms 1 original) and also replace a pipe/hose assembly with an updated part number) which feeds one of the accumulators
Stuff that arent 100% necessary but are things that can be done to improve things while in there.

and thank you, i think ill try and remember and put my scan tool on it tomorrow after work and see what kind of things it shows me
I can only plot 3 PIDs at one time on a graph BUT i can save minutes of PIDs on theoretically a whole bunch of them. Does a 2005 chevy truck have a transmission control module or is it still controlled by the PCM that year? In 2006 I know a lot of gm cars went to a transmission control module