214K 6L80 rebuild before TCC failure

[swathdiver]

Me, take a whole transmission apart?! Ha. I guess you gotta start somewhere?

No, he went in from the pan and modified the TECHM and valve body. @skpyle

 

[iboughtatahoe23]

No, he went in from the pan and modified the TECHM and valve body. @skpyle

I wanna see that. But first I wanna know what for sure is going on.

 

[skpyle]

https://www.tahoeyukonforum.com/thr...-flush-in-2013-escalade-esv-pic-heavy.130110/

Here you go, iboughtatahoe23!
The 6L80 is not intimidating if you take it step by step.

Good Luck!

 

[RobH]

Put the slip to ZERO in 5th and 6th... I didn't see if you were still using the DOD/AFM but that's a big reason why there is so much slip built in
Get rid of lock up in 1-3 gears altogether. Some say even 4th gear, but I like having the lock up in 4th above 42 mph.
I also set my upshift part throttle shifts to something not so dumb..
No more hunting for gears and then bogging only to downshift
It just takes some patience and trials to get it where YOU want it. I have seen
no decline in MPG either. I really really enjoy my 6L80E now .. stock it sucked !!

With my 1995 OBDI Caprice 4L60E, I did something like this using the TunerCat software. I was a lot happier with the results in transmission behavior. And I believed that I was helping longevity of the transmission and engine by reducing transmission up and down shifting and engine lugging.

I basically like my 6L80E, but would definitely like to do some tweaking as described by Foggy. Especially if it would help the life of my just installed GM reman tranny. I'm not drag racing; I'm not looking for "higher performance". But I'd like to turn off the DOD/AFM and get the transmission to not lug the engine running below 1500 RPM.

I like the idea of getting rid of the lockup in 1-3 and moving the 4th lockup above 40 mph and 5th and 6th above 50 and 60 respectively if there are no longevity downsides.

What software are you using to do the tweaking? Or are you having to hire it out? I'm not sure about paying someone else for multiple tweaks to get the transmission behavior where I want it, with delays in tweaks. I'd rather buy the software and do it myself.

I usually put the transmission in neutral when at a stop light for a while. My thinking is to reduce churn in the torque converter with heat rise and load on the engine at idle. Is there any downside to that? I do have the service bulletin 70°C transmission bypass valve.

Thanks in advance.

 

[Foggy]

With my 1995 OBDI Caprice 4L60E, I did something like this using the TunerCat software. I was a lot happier with the results in transmission behavior. And I believed that I was helping longevity of the transmission and engine by reducing transmission up and down shifting and engine lugging.

I basically like my 6L80E, but would definitely like to do some tweaking as described by Foggy. Especially if it would help the life of my just installed GM reman tranny. I'm not drag racing; I'm not looking for "higher performance". But I'd like to turn off the DOD/AFM and get the transmission to not lug the engine running below 1500 RPM.

I like the idea of getting rid of the lockup in 1-3 and moving the 4th lockup above 40 mph and 5th and 6th above 50 and 60 respectively if there are no longevity downsides.

What software are you using to do the tweaking? Or are you having to hire it out? I'm not sure about paying someone else for multiple tweaks to get the transmission behavior where I want it, with delays in tweaks. I'd rather buy the software and do it myself.

I usually put the transmission in neutral when at a stop light for a while. My thinking is to reduce churn in the torque converter with heat rise and load on the engine at idle. Is there any downside to that? I do have the service bulletin 70°C transmission bypass valve.

Thanks in advance.

I use HP Tuners. You will need the software/cable/dongle package. The rest is just downloaded from them.
Then you will have to buy credits. Yours is a 2016 so I'm not sure how many, you can look
it up on their website. Once you do this, You can make as many changes whenever you
want to. But this initial cost is pretty high for just 1 vehicle to be tuned.
You might be better off paying someone or a company to do a tune for you

 

[mikez71]

My current tune is to increase the TCC pressure (well below what others are using), bump the apply ramp on the plus side to 1.5x stock plus 10kPa, and to roll the 5/6 slip from 20 at low rpm to 10 at 2000 with a gradient in between, and reduce the adaptive to +/-5 psi. With that the slip logs close to zero under most conditions, so I think I am in an overshoot condition, where I have plenty of pressure to lockup at what the computer characterizes (guesses) at about 42-46 psi.

Can someone explain these settings in greater detail?
On the apply ramp, it looks like 1.0 is fully applied and 1000 is fully disengaged?
Looking for suggestions on reliability tune for a stock tranny. Sounds like TCC desired pressure/apply ramp/slip tables can use tweaking?
Also why 0 slip in 5&6 but not 4th? Currently I have TCC off in 4th, but I am thinking about turning it back on for slower speed cruising.

The one negative effect of turning off TCC lock in lower gears is..
Going slow down a steeper hill and coasting, when re-engaging the throttle to slightly speed up, the converter slack takes a second or two to catch up.
I'm guessing this happens around 20mph in second gear..
It looks like stock earliest engagement is 12mph in 2nd gear(3.08 gears).

Can I TCC lock in 1st gear only at low throttle? I'm thinking TCC engagement at low throttle might make for a more stable slow state cruise..

 

[MWD_CTSV]

Can someone explain these settings in greater detail?
On the apply ramp, it looks like 1.0 is fully applied and 1000 is fully disengaged?
Looking for suggestions on reliability tune for a stock tranny. Sounds like TCC desired pressure/apply ramp/slip tables can use tweaking?
Also why 0 slip in 5&6 but not 4th? Currently I have TCC off in 4th, but I am thinking about turning it back on for slower speed cruising.

One thing I am curious if it can be tuned out is..
Going slow down a steeper hill and coasting, when re-engaging the throttle to slightly speed up, the converter slack takes a second or two to catch up. This is a pretty slow speed but I'm considering turning on the TCC for lower gears as well. It looks like stock earliest engagement is 12mph in 2nd gear(3.08 gears), whereas I've upped my shift speed to 13mph, so might engage at 14mph if I mirror the original offset between shift speed and tcc engagement. The speed where this is ocurring, I maybe going slower than that..

Can I TCC lock in 1st gear only at low throttle? (In which case I might turn it on for all gears at low throttle settings)

Apply ramp is a pressure adder, meaning that it will add the number to the desired TCC pressure. Making changes to the right of '0' slip increases the pressure to the clutch when the TCC has more slip than desired, which should reduce the slip. With HPtuners you can change the units that you are editing in, which can include psi. For the default kPa, 1.0 would be a minor increase and 1000 would be 100% wide open line pressure on the TCC, which might cause more issues than the slip (breaking a piston or a seal).

TCC slip is just the rpm difference between the engine side and the transmission side of the converter. The desired TCC slip, is just the slip target that the trans is trying to achieve. Setting the desired TCC slip to 0, reduces the actual slip which theoretically leads to less wear on the clutch.

The basic idea behind only using TCC lockup in 5&6 is to reduce usage to where the real benefits fuel usage are the highest, and where you can cruise below the stall speed. The ATSG manual says that TCC lockup is not available in 1st, but there is a table row for enabling 1st gear TCC in the tuning software.

 

[mikez71]

Thanks, looks like I had the apply ramp backwards! Still trying to understand why the apply ramp has a couple odd spots in the low torque (and negative torque?) and negative slip area. Maybe engine braking? (I'm assuming negative slip is when the wheels are turning faster than the motor?)
I had heard that stock pressure was not enough to keep slip at 0, and too much pressure can warp something.

Any real downsides to locking TCC in 2,3,4 gears? The downhill issue is the main reason I'm thinking about turning it back on. Reason I haven't is needing to adjust the lockup maps to coincide with new shift maps.. Figure I'd dial the shift maps in first so I don't have to tweak a bunch of maps everytime! Light throttle application should be more efficient/responsive I am thinking.

Anyhow, thank you for the explanations. Any other bits you can offer, please let us/me know!

 

[MWD_CTSV]

The only real downside to locking in the lower gears is wear on the TCC. Driveability is possibly an issue, because if you are locking ******* the upper gears, it could be more abrupt in the lower gears.

Yes, negative slip is engine braking.

The only effective way to get a solid lock on the single clutch is to increase the initial pressure which is effectively offset/gain. In many cases the stock setting is 26 psi and the gain is 1.5, so the initial pressure or minimum pressure is 26/1.5, which is pretty low and will not completely lock at 50% throttle even if you set the desired slip to '0', unless maybe you set the apply ramp to some really high pressures. However, setting the desired slip to '0' will still get a lot less wear at whatever lower slip it experiences, without forcing a lock with higher minimum pressure.

 

[Christoph]

I went with the billet cover CVC BU60FHD that was recommended here. A friend offered a CTS-V converter, but I still chose the CVC. I also did a new pump, slide and spring along with the Sonnax zip kit, which includes several items to help with pump pressure regulation and the TCC specific one, that is recommended by the rebuilder (CVC) to help the life of the TCC.

Where were you able to you get your torque converter? Thanks in advance.

 

[Geotrash]

Where were you able to you get your torque converter? Thanks in advance.

I have the same one that I purchased through a local Indy transmission shop. I believe Summit carries them also.

Edit: confirmed and VEGE is the manufacturer now. I believe they bought out CVC.

Pardon Our Interruption

 

[MWD_CTSV]

I bought my converter from transtar which supplies many of the local transmission shops, but their retail price is higher than Summit. Mid $300 is still pretty good for the billet cover and flanged hub upgrades.

It will be interesting to see if the 2020+ 2500 stock GM converters are a good upgrade choice as Circle D recommends. Rebuilt ones from GM are under $400.

 

[BLZNHOT]

Definitely agree with replacing the converter at 125k or so regardless of whether its working well or not as they are ticking time bombs…Did you upgrade the converter clutch to the thicker version’s available (.045 or .066) and have a billet cover installed?

Here’s some info on those JMBX converters:

Gears Magazine - Flex & Bend - A Look at the 6L80/90 JMBX Torque Converter

The GM 6L series transmission is quickly becoming the most popular attraction in the shop. As we all know, this unit is plagued by a handful of common issues, such as pressure switch filament cracking, 35R drum breakage, 1234 piston cracks, valve/bore wear, and converter failures. The drum...

gearsmagazine.com

Nick i have a 2011 tahoe 72000 miles shift fines ,serviced trans at 50000 when i got it, just got a tune with lockup 1-4 out some tcc slip ajustments made and afm disabled, and ecm tuned also before i heard about these tunes i was going to get a precision of new hampshire billet cover converter as a proactive measure , but now with the tune it shifts so nice (not that i had a problem before ) I'm thinking about letting it ride and service every 30000, whats your thoughts about the proactive converter change????????????

 

[j91z28d1]

Nick i have a 2011 tahoe 72000 miles shift fines ,serviced trans at 50000 when i got it, just got a tune with lockup 1-4 out some tcc slip ajustments made and afm disabled, and ecm tuned also before i heard about these tunes i was going to get a precision of new hampshire billet cover converter as a proactive measure , but now with the tune it shifts so nice (not that i had a problem before ) I'm thinking about letting it ride and service every 30000, whats your thoughts about the proactive converter change????????????

I am definitely not a tranny guy so my 2 cents might not be worth 2 full cents haha. but for me, it depends on who's doing the work. if your are dropping the trans and putting a new converter in yourself. I'd definitely do it as preventive. trannys are expensive.


but if you gotta pay some shop 5k labor to replace a converter or 7k for a whole tranny rebuild. that's a harder decision.

 

[BLZNHOT]

Nick i have a 2011 tahoe 72000 miles shift fines ,serviced trans at 50000 when i got it, just got a tune with lockup 1-4 out some tcc slip ajustments made and afm disabled, and ecm tuned also before i heard about these tunes i was going to get a precision of new hampshire billet cover converter as a proactive measure , but now with the tune it shifts so nice (not that i had a problem before ) I'm thinking about letting it ride and service every 30000, whats your thoughts about the proactive converter change????????????

I didnt do anything yet , will probably change converter well before 100.000 got 72,000 now, what your thought on precision of new hampshire converters or what do you use?

 

[Fless]

I didnt do anything yet , will probably change converter well before 100.000 got 72,000 now, what your thought on precision of new hampshire converters or what do you use?

Are you asking @NickTransmissions? If so, be sure to 'tag' him like I did here. Start with the "@" sign and start typing your target's username.

 

[NickTransmissions]

I didnt do anything yet , will probably change converter well before 100.000 got 72,000 now, what your thought on precision of new hampshire converters or what do you use?

I'd swap to a better converter sooner rather than later. Obtain one that comes with a .070 thick Borg Warner high energy clutch installed and you'll be good....Billet cover and/or flanged hubs add strength but not really needed for a daily driven, otherwise factory vehicle.