Normal Shift Table/ TCC Apply Release Speed table,...what???

[Hutchinson]

Good day guys,

I had my truck dyno tuned a few weeks ago by my local tuner,....looks like my local tuner increased my Normal - Shift Speed table,... but, when I look at my TCC Apply Release Speed table, it's very low (in comparison to the shift speed table),.... can you guys have a look at the attached tables (screenshot) and put your expert eye on it?,... I've included both tables for quick reference.

Basically, as an example,.. at 25% throttle, I shift into 4th gear at 49MPH,...yet at that same 25% throttle, my TCC Apply for 4th is 28MPH??? Can this be right???? Additionally, when I look across the length of the entire TCC Apply/Release table,...I thought all the "release speeds" were ALWAYS supposed to be lower than the "apply speeds",... or am I wrong here???

Maybe this is why I'm getting a loud/quick shudder type noise from my transmission when my truck downshifts under a slightly heavy foot????

Thank our Lord for HPTuners,.... without it I would have never guessed.

My Truck;
1996 GMC K1500 4x4
5.7L swapped to an HT383e
0411 swap from LexTech, with his base tune,....originally, before local tuner got into it
FLT Level 5 4L60e with Sonnax 3-4 drum upgrade
3.73 rear


TCC Question.png

Thanks guys for the help.

[Area47]

well, thats two problems now from the same guy. id find a new guy. typically lock up is higher than shift speed

[Hutchinson]

Yes sir,...and he's supposed to be one of the best,...I guess he didn't like the way I smelled that day, or I didn't smile at him right,...or something,....Hell, I don't know,...

Is there a typical rule of thumb to use when setting these two charts so they are compatible? My Normal Shift Speed table/ shift points are OK on the street,...I might tweak/lower them a tad,... but overall OK,....what would y'all propose for the TCC Apply/Release numbers/guidance on how to do this correctly?

Thanks again Area47.

[Hutchinson]

Anyone have a rule of thumb for setting the TCC table to coincide with the normal shift table,..per the above?

My local dyno tuner adjusted my shift speed's much higher, but didn't adjust my TCC table. Now, when I down shift under hard pedal, I get a very loud/quick/hard shudder type noise from the trans,...I'm thinking it's the TCC locked while putt-putting (when it shouldn't be), then trying to unlock/relock quickly due to settings in the two tables not being compatible.

Any help would be cool,...I dropped the trans pan and found a lot of clutch material/metal flakes/shavings,...and I'm thinking it's due to that loud/hard/1.5 second shudder sound.

I tried BlueCats trans tune spreadsheet but,...don't know if I did everything right,....thus kinda worried bout inputting those numbers/using it,....I'm still too new to trust my own changes,...yet,...till I can get someone's guidance on here. Thanks guys.

[Hutchinson]

Bump,...anyone??

[Hutchinson]

Well guys, I used BlueCats trans tune spreadsheet (found on this forum) to formulate/reset my normal shift point tables and TCC apply/release tables,....and I'm gonna try it today.
All my torque management tables had previously been set to zero so,...I put the stock torque management numbers back in and halved them,..ended up with 50% torque reduction. My abuse mode table had also been zero'd out but, I left that zero because I don't plan on doing any "burnouts while holding the brakes".

I set my scanner up to record pertinent trans info and will take the truck for a run on the existing trans tune (to get a baseline/further diagnose the current issue),...then upload the new BlueCats shift/TCC numbers and rerun/rescan.

That BlueCats spreadsheet is cool guys,... check it out if you ain't already. I don't see how anyone could set up the TCC apply/release table without something like this,....given my situation above. Thanks for providing this for us BlueCat.

[just_injones]

i cant find that spreadsheet. im having problems with my torque converter going from locked. Give it throttle and the rpm jump up unlocks the TC, then it applys.

[Hutchinson]

Go to the search page and type in (under the username window) "BlueCat" and it'll show multiple post from him,...one being Transmission tuning software (or, something like that). Let me know if you can't find it. It truly is a cool spreadsheet, I played with it the other day,.,,adjusting a few of the settings he has (in the spreadsheet) to see how the changes affected main shift tables and TCC lock/unlock.

Just make sure when your done (the software spreadsheet has a direct upload function), go back into your tune and look at your shift points (in the 2D chart) and assure they follow this;

Part Throttle shift table relationships (looking at shift curves in 2D):
1->2 curve should be above 2->1 curve;
2->3 curve should be above 3->2 curve;
3->4 curve should be above 4->3 curve;

additional relationships:
3->2 curve should be above 1->2 curve;
4->3 curve should be above 2->3 curve;

This can be summarized as: the curves cannot cross anywhere;....if they cross anywhere, then you will not be able to predict what gear the PCM selects when the operating point hits the cross.

I got the above from another website forum "moderator type" person and found the philosophy to be correct on several stock tunes.

[tramotorsports]

I sometimes use his spreadsheet as a starting point if I'm building a new base. All other changes come from driving the vehicle and actually feeling it. Leaving converter unlocked in the lower gears typically helps the vehicle "feel" better imo. Lockup speeds are up to the driver and how their daily commute might be. I always make customers report back on shifting and lockups.

I usually set the rpm shift points in the Trans calculator a little lower than what I actually want to shift at. This lowers the WOT shift speeds enough that you wont hit the limiter between gears and long as the shift times are on point.

Remember; a heavier vehicle, lifted, big tires, not enough gear, will require more throttle input to move at the same rate as a smaller vehicle with less resistance. This is why the calculator should only be used as a reference or starting point. Just plugging in numbers from the calculator can have some vehicles on the money and other vehicles Hunting for gear and going through unlock/lock like crazy.

[Hutchinson]

Yes Sir tramotorsports,...I agree with everything you wrote. It's best if you can start with stock settings, and scan/tweak from there,....for those that can't, man, that BlueCats sure is handy for setting up your base shift tables/TCC. If your simply changing tire size or gear, HPTuners sure makes it easy with their Wizard/auto table updating feature.

My case was, when I rebuilt the truck - I did it all at the same time (per signature),...when I eased off on its maiden voyage, I found it was shifting into 4th at 24mph,...with TCC locking up by 28 (under light throttle). Yeah man, that new 383 was lumbering from low engine rpm shifting ranges,....
So, I took the PCM to my local dyno tuner and he simply slapped a "copy/paste" shift table in (lord knows what vehicle it was from),....but, never adjusted the TCC table to suit,....his simple "copy/paste" put me on the other end of the spectrum, shifting at excessively high speeds per gear,..and with TCC all jacked up. Took it to him again and he messed with it some more,....in the end, it was all screwed up,....and he hadn't even saved a copy of my original tune so I could start over. I didn't know anything bout tuning then,.,,it was all ancient Swahili to me.

Thought, "screw this",...got HPTuners,....and did it myself. I've learned lots over the past months (thanks to the guys on here),....and the rest is history,......can't thank the guys on this forum enough for helping me. Lots of good dudes on here man.

[G8-4-speed]

TCC mph wasn't causing your issue. Although not ideal it is just the lowest it will allow TCC IF in that gear. Your issue is with Torque management, shift time, shift pressure and possibly MPH tables. I have seen some tunes request two different gears at the same MPH which will eventually break parts. These transmission are "adaptive" so when you remove TM, the tq value increases dramatically which will calculate a higher shift pressure up or down. In some cases will cause harsh upshifts or downshifts. All TCM's act a little different and may need more adjusting as the tune settles(as it relearns). These transmissions can be very complicated to tune when considering the "adaptive" learn factor. Sometimes the tune can be right but the learned value has not reset to work with the new settings. You can tune in circles until you understand "when" to do "what" with these transmissions.

[Jason B]

I have seen some tunes request two different gears at the same MPH which will eventually break parts. These transmission are "adaptive" so when you remove TM, the tq value increases dramatically which will calculate a higher shift pressure up or down.

This is hilarious, tell me how you put a 4L60E in two gears at the same time, PLEASE. I need to know this. The shift solenoids will not allow being in two gears at the same time, any combination of on and off just puts it completely in ONE gear.
The transmissions are adaptive? How? The programming can be made adaptive but it's default is non adaptive.

Someone might buy this if they altered their programming yesterday. Someone thats done it 10 years ago and never seen any of this happen, well thats another story.

[Hutchinson]

I should close the loop on the issue,...wherein I stated above:
may be why I'm getting a loud/quick shudder type noise from my transmission when my truck downshifts under a slightly heavy foot

This was all in the early stages of my learning/trying to diagnose my 4L60e issues,....man, I've learned a lot in 3 months from all you guys,....and I want to say a big thank you,....I'd buy you guys several cold beers if I could.

I thought (although I WAS wrongly stabbing in the dark) it may have had something to do with my TCC getting confused with the normal shift table (again, I was stabbing here fellars). Yet, come to find out, this had nothing to do with it,.....
The "load/quick shudder type noise" I had was actually my internal trans clutches not grabbing/shudder slipping because my PCSolenoid was not adjusting line pressure to suit trans load from delivered engine torque increases/decreases and or throttle % position.
When I hooked up my line pressure gauge, I had a constant ~84psi in all forward gears,..and it wouldn't move from that 84,....even when I stomped the gas.
Thus, to further test this, I unplugged the main wiring harness to/on the trans and started the engine - this should have made my line pressure jump to max (~220psi) because there was no current going to the PCSolenoid (it is designed this way by GM to protect the trans if 12VDC is lost to the trans),....yet, my pressure gauge still stayed stuck at ~84psi,...... Thus, this was final proof that I indeed had an internal trans mechanical issue going on,..and it wasn't something from/to the new 0411 PCM swap/wiring I'd done at the same time I'd installed the new rebuilt transmission.

Since this time,...I took out the old rebuilt trans (only had 363 miles on it, and was burnt slap up),....installed a new Finish Line Transmission (FLT) Level 5 and slapped the line pressure gauge on it,...all's good now. My line pressure proportionately goes up/down with throttle position% and or delivered engine torque. Thus proves my PCM/wiring good, and old trans definitely had a mechanical pressure issue internally.

I must agree with JasonB,...man, I can't see how a 4L60e trans could be put into two gears at the same time. Maybe he'll chime back in and further explain what he means with this.
I'd also like to hear more on how the adaptive thing works too,....maybe adaptive over time to account for clutch wear/shift???? I don't know,....I'm still new to all this,.... I have read about shifts becoming softer over time due to something being "adaptive",...but that's all (and I haven't looked into any of that yet). Also like to know what he meant about "Sometimes the tune can be right but, the learned value has not reset to work with the new settings". Maybe he's thinking of another transmission type??? Again,....maybe he'll chime back in and further explain.

[Jason B]

I must agree with JasonB,...man, I can't see how a 4L60e trans could be put into two gears at the same time. Maybe he'll chime back in and further explain what he means with this.

Me chime back in? I think whoever said it can be put in two gears at the same time needs to explain that one. I know it's impossible. If someone thinks it is possible I'd find it quite entertaining.

Also like to know what he meant about "Sometimes the tune can be right but, the learned value has not reset to work with the new settings". Maybe he's thinking of another transmission type??? Again,....maybe he'll chime back in and further explain.

I didn't say that.

This is one complicated thread. We diagnosed a transmission that wasn't going to be used only to find that the one that was going to be used worked fine. (and probably would have been fine if it was installed first).

[Fast4.7]

Me chime back in? I think whoever said it can be put in two gears at the same time needs to explain that one. I know it's impossible. If someone thinks it is possible I'd find it quite entertaining.



I didn't say that.

This is one complicated thread. We diagnosed a transmission that wasn't going to be used only to find that the one that was going to be used worked fine. (and probably would have been fine if it was installed first).

He was agreeing with you and wantimg G8 to chime back in.

Some transmissions like the Jatco 7spd in my M56S are highly adaptive. I cannot stand the POS. Wish it had the 5spd from my old Titans in it. 1/2 mile of stop and go traffic has the thing shifting like an inexperienced stick shift driver. Torque converter jolting into lockup right after a 1-2 shift and bogs the engine down to 900 rpm. Get it in some open road though and 1/2 throttle upshifts are happening at 6,000 rpm in no time.

[Hutchinson]

Yeah man,...I was agreeing with you JasonB on both counts,,..and wanted to see if G8 would chime back in on both counts (on the 2 gear thing, and the adaptive comment). My bad, for not spelling out who I was referencing.

Secondly, as history,....I installed the first locally rebuilt 4L60e (during the total truck rebuild),....it went to shit,......

Then, I ordered the FLT.

While I was waiting for the FLT to arrive, I was determined to find out exactly what was wrong with the first trans I'd installed,....thus, did all the testing (with y'all's help - thank you) and found out what the problem was,....mechanical pressure problem inside trans. I wanted to assure I didn't have the same problem when I installed the new FLT trans.

I then installed the new FLT trans. (Sure wish I had the FLT trans first),....And, I sure would like to legally punch my local trans builder in the mouth a few times,..for all the trouble he caused me. Live and learn I guess.

Yeah Fast4.7,...I'm thinking (only guessing) that G8 is thinking of another trans type,.....not a 4L60e. What G8 posted really doesn't apply to a 4L60e,....unless G8 can come back and explain what he means better.

[G8-4-speed]

Sorry, it is mainly an issue on 6L80/90's.

[Hutchinson]

Cool man, kinda figured that's what you were talking bout. It's cool bud.