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I rebuilt my 4l80 myself. Typical build, internally dual fed, sonnax boost valve in pump, thicker intermediate snap ring, the works. Nothing crazy. ALL electronics(wiring, sensors, solenoids) new. Endplay set tight but hopefully not too tight.
Now to the issue. Trans only has third, fourth and converter lockup. All behavior seems normal, except just no first gear, and some weird stuff happens when second gear is commanded in my vehicle at 60mph at WOT. This is all confirmed by datalog too (Holley Terminator X Max). Once second is commanded my rpms jump 400rpm,(I believe what is happening is a 3-2 downshift where it is supposed to be a 1-2 upshift) but rpm are still not as high as they should be.
Fluid is full and dipstick is correct, I have made a whole new tune file from scratch as when I first swapped the trans first gear was not even being commanded by ecu. Now it is commanded but third gear starts.
I believe the intermediate clutches are dragging, basically causing third gear. I really had to work the thicker snap ring into the groove in the case but still had decent clutch clearance, maybe like .030. What would happen if the plug in the case for the dual feed fell out? What do you guys think?
What file format can I attach a datalog in? For now I can snapshot.
So what is happening in the blue circle is I am full throttle or near at like 50mph(should be first gear), ECU is commanding first, but rpms say third. Second gear is commanded at 60MPH and then rpm goes up 400 to 3300 but are still below where they should be at 3900 according to calculator online.
Tire diameter 26"
Rear axle ratio 3.27
First unplug harness from trans with the 80e you should be able to select 1-2 manually this will let you know if you can mechanically make those gears.
If a plug fell out you would just have low 3rd gear apply pressure though if you used typical cup plug it's an unlikely thing to have happened.
The .30 clearance on intermediate should be fine but did you make sure second braking band not dragging or locked down it will cause what feels like a slipping 2nd gear start and cause issues with 3rd, The clearance of the clutch set would have opened up .10 to .20 after a few applys.
This is not a 4l60e to 4l80e swap is it ?
__________________ Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
I do not believe there are any wiring changes that need to be made to run a 80e vs a 60e with Holley. Just change the transmission selection in the tune.
First unplug harness from trans with the 80e you should be able to select 1-2 manually this will let you know if you can mechanically make those gears.
If a plug fell out you would just have low 3rd gear apply pressure though if you used typical cup plug it's an unlikely thing to have happened.
The .30 clearance on intermediate should be fine but did you make sure second braking band not dragging or locked down it will cause what feels like a slipping 2nd gear start and cause issues with 3rd, The clearance of the clutch set would have opened up .10 to .20 after a few applys.
This is not a 4l60e to 4l80e swap is it ?
With the 80e, unplugged harness in 2nd. OFF/OFF solenoids in 2nd.
In M1 shifter, the solenoid pattern still overrides the M1 selection...you'll have 2nd. This was by design as a "safety shift" for pickups so they didn't over-rev especially downshifting to slow
As for the OP's issue...I'd wire up a super simple manual control box, plug it in in place of the holley harness...and make sure the trans is functioning properly.
Manual control box is very simple
Just get an "external repair harness"
Then:
Just supply power to the E pin,
Butt connect Pins N&R to pin A
Butt connect Pin P to B
Pin S is for lockup. Not needed for your testing, but if you wanted to put it on a toggle switch you could. Just supply ground to pin S when you want the converter to lock
With this little contraption, just plug it in and give it power to E...then whatever shifter position you're in...is the gear you should have.
It eliminates the holley from the equation and lets you confirm the trans is working.
Once you've confirmed that...you know all of your problems lie in the holley and you can start tracking those issues down and not worrying about if the trans has an issue or not.
Hmm its possible I am mistaken Been a while since i i have messed with an 80 in limp mode, I was thinking it was like the 60e except instead of defaulting to 3rd with manual selection possible to 2nd it defaulted to 2nd with manual first selection possible. Maybe I am thinking of the E40D, In any case we agree determining trans viability is the first move.
__________________ Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
I unplugged the connector and went for a drive this weekend, the trans is still holding 3rd gear even with the connector unplugged. Would a sprag installed the wrong direction/upside down cause this issue? Specifically the intermediate sprag. Based on this diagram it seems either the direct clutches will not release and/or intermediate sprag is not "holding".
Currently the trans has 3rd, 4th, converter lockup and reverse.
Does eliminate the VB as an issue? ie stuck valve somewhere.
with the direct sprag flipped you will have no 2nd gear (and thus no 3rd or 4th) I think you will have 1st and reverse (going from my foggy brain)
are you reading that it's in 3rd from the holley? holley reports data from the pressure switch, so it will only tell you what circuits are being energized hydraulically, not what elements are actually holding. And with the main plug off, the pressure switch will send no data (not sure how holley will interpret that and show on the scanner)
and just for ***** n giggles, double check the main plug is not upside down. The arrow should be on the top of the transmission. The holley plugs are flimsy enough to put this on upside down and it will act just like you say.
I have also seen 3 holley transmission harnesses mis-pinned and causing weird issues.
I was under the impression that holley calculated gear by only mph and tps. (pressure/pillow switch irrelevant)
My holley is reading/displaying the correct gear(so by your thinking with the pressure/pillow switch I am getting hydraulic pressure at the right time) but my rpms say different. It is like something is binding or rotating/not rotating.
I am calculating that it is in third gear by mph and rpm. At 90mph at WOT I'm at like 3700rpm. Should be just under 6000rpm there. Its definitely third gear.
I do not think that the connector is pinned wrong because it was working perfect on my 4l60e last month. I would assume the 80e uses some pins that the 60e doesn't that could be pinned incorrectly though. Will have to look into the pinout on the harness.
I also double checked when taking the connector off last weekend that it was in the correct orientation, so we are all good there.
If the holley does in fact read gear from the pressure switch, and not by the up/down shift tables in the tune, then my valve body is working correctly. That would mean my issue lies inside the barrel/ case of the trans or I have a crossleak/crack in something.
when auto shifting, yes it uses the mph/rpm/tps lookup tables to command shifts. however the displayed current gear will be read from the pressure switch. you can test this by plugging in an internal harness and pressure switch and depressing the switch film elements (use the eraser end of a pencil, the film is fragile) and watching the scanner.
I agree, it sounds like something is bound up. I would first drop the VB to air test all the apply feeds
in all my builds i aways lean to a having clearances on the loose side instead of tight. on your build concerning the intermediate clutches 30 thousandths would be considered too tight. you also said you had to really work to install the thicker snap ring. when the clearances are correct either the original or the thicker snap ring should install with no effort, they almost fall in. i know a 5-10 clearance per friction is the norm but this cannot be applied to the intermediates in either the 4l80 or th400. the reason being is the height of the splines on the intermediate race. tightening up that clearance with more clutches and/or thicker pressure plate, when the piston applies you probably have clutches that don't even engage. 60-70 thousandths is a acceptable clearance. i do change the apply piston and retainer to a th400 set up for a firmer shift and better holding power. input and output clearances i shoot for 5-10 thousandths for the output and 10-12 thousandths for the input. i remove the cushion/wave plates in both direct and forward because i've seen these hang up in the lower groove of these drums. i make sure the first steel is thick enough not to hang up in this groove either. the only clutches i make a little tighter are the forwards, about 30 thousandths no matter how many frictions i shove in there. this is acceptable since forward is always applied except in reverse.
The pressure manifold switch only shows the current manual gear selection 1-2-3 od position not the actual gear. The current gear display is only telling you what the TCM is commanding, not if it actually happened. The only way the TCM knows if a gear shift occurred is via input and output speed reading..
If it listed current gear as lets say 2nd then that is what is being commanded or its in limp mode which is default.
I always keep the wave plates (I use 2 they can also be rotated with each other to add or take clearance)) in the fwd clutch as I have had customers complain about harsh engagement on RND when I didn't in the past and I feel it hard on the input sprag.
I do remove it from the direct clutch and replace with a thick steel from a th400 at bottom.
I set all clearance at .020 to .030 as I have noted after running a short few shifts and tear downthey open up another .010 to .015
If I wanted to verify trans function in first, I would set limp mode then rig up a switch to ground solenoid A this should force first as assuming PIN E has power as it should even in limp mode the solenoid should engage and make 1st gear if it does then trans is sound if not then you have some valve body or internal issue..
__________________ Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Instead of messing with this more, I just broke down and brought it to my transmission guy. I want to enjoy my car this summer and not have it be down and frustrating me.
My guy says quote...
"Got it tore down, you had check ***** in the wrong places, your accumulator for low clutch was stuck in the bore, low roller clutch burnt. Band is ok. Missing selective washer on forward clutch hub."
Boo. So yeah...I screwed it up! I think if I try another transmission I will have a head mounted go-pro so I can rewind at watch how everything came apart. I want to get one right. Huge learning curve with these GM overdrive transmissions, there is a lot going on inside these units.
I should be installing it this weekend.
Instead of messing with this more, I just broke down and brought it to my transmission guy. I want to enjoy my car this summer and not have it be down and frustrating me.
My guy says quote...
"Got it tore down, you had check ***** in the wrong places, your accumulator for low clutch was stuck in the bore, low roller clutch burnt. Band is ok. Missing selective washer on forward clutch hub."
Boo. So yeah...I screwed it up! I think if I try another transmission I will have a head mounted go-pro so I can rewind at watch how everything came apart. I want to get one right. Huge learning curve with these GM overdrive transmissions, there is a lot going on inside these units.
I should be installing it this weekend.
I have a turbo 5.3/ 4l80e setup in my truck making roughly 500whp so nothing crazy, I have this same issue besides I will have 1/2/3/4 and lockup just fine unless I do a rip (doesn’t matter what gear or speed, doesn’t do this every time usually less than often but afterwards I’ll come to a stop and take off again like a stop sign or something and I’ll be taking off in 3rd… and it shifts fine. I found parking and shifting from reverse to drive (sometimes a few times and moving back and forth) will make it snap out of it and shift all gears normally. Does this sound to be the same issue you had? I had a shop do the swap and they already looked at it again last year and didn’t find anything.
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4l80 third gear only and other weird stuff... 
