[PolynesianPowerhouse]

Originally Posted by JaxChris

This thread was started by one of the two people I would go to first for a safe email tune if you already own your own HPT cable and spent the credits on your vehicle. And for someone that hasn't gone crazy with their power mods, both of these guys are more affordable than Matt was.

EFI Tuning - Tim - Mt Dora, FL
Tampa Tuning - Phil - Tampa Bay, FL

Central Florida is lucky to have a number of good GM tuners. Not sure if Tim does LGX, but he is an E85 pioneer on the 6th gen (unfortunately no corn gas in the Aloha state). Phil does do LFX/LGX, but he charges +100$ over his normal fee for direct injection motors (including LT1/LT4/LTG as well).

Higly appreciate that info. Def a great post to learn from.

[KonigWolf]

Originally Posted by EFI Tuning

I noticed that if I command the TC to lockup manually (via HP Tuners) it goes to maximum pressure and it will not shudder at all. As of the most recent beta HP Tuners has added some additional TCC tables. I began doing some testing and for a few days now I have not had the shudder occur at all.

There are allowable slip tables per each gear relative to engine torque output. At low torque output GM allows up to 10 RPM of slip. This results in minimal pressure on the TCC apply. This is the design intent but because of whether it is a fluid friction modifier issue or a clutch material issue on the TC it allows the shudder to be felt.

Are you referring to version 3.7?

[KingLT1]

yes 3.7...I just had Hp tuners support update my account so I can download it. The caveat is it's not backwards compatible, so( Correct me if I am wrong.)you will want to flash your stock tune, reread the ECM with 3.7, save the new stock file, then modify and flash from there?

[EFI Tuning]

You can use the old stock file with 3.6 if you need to flash back to stock. The backwards incompatibility is a bit of an annoyance. I wish they would update 3.6 to handle 3.7 opening and flashing.

Keep solid backups!

[KingLT1]

Have a question. I was under the impression that it took 4 credits to access both the ECM and TCM with HP tuners? When I licensed mine it only required 2 credits and it will let me flash both the ECM and TCM.

[EFI Tuning]

16s use the E92/T87 controllers. For 17+ they moved to E92A/T87A which bring the additional steps and cost. It makes for a costly venture if you want/need to touch the TCM.

Tim

[KingLT1]

Just want to update that this has worked for me. I have not logged a ton of miles, but so far no issues.

[bodysnatcher]

I have the 2.0 T and it is doing it (Shuddering) when transmission fluid temperature reaches 147 Deg, So I am wondering, I know I have to bring the car to the dealership, but from what I am gathering, the three flushes wont work?, and is replacing the TC gonna work?

[KingLT1]

Originally Posted by bodysnatcher

I have the 2.0 T and it is doing it (Shuddering) when transmission fluid temperature reaches 147 Deg, So I am wondering, I know I have to bring the car to the dealership, but from what I am gathering, the three flushes wont work?, and is replacing the TC gonna work?

Take it to the dealer and have the TSB done...50/50 chance it will come back. The next recourse is to try the tuning.

[Camaro1061]

Originally Posted by EFI Tuning

I had the shudder start on my car last spring (MY16). I had the flush procedure done and for about 4 months it was resolved. Unfortunately the shudder has returned.

I noticed that if I command the TC to lockup manually (via HP Tuners) it goes to maximum pressure and it will not shudder at all. As of the most recent beta HP Tuners has added some additional TCC tables. I began doing some testing and for a few days now I have not had the shudder occur at all.

There are allowable slip tables per each gear relative to engine torque output. At low torque output GM allows up to 10 RPM of slip. This results in minimal pressure on the TCC apply. This is the design intent but because of whether it is a fluid friction modifier issue or a clutch material issue on the TC it allows the shudder to be felt.

I changed the table to allow 0 slip in 7th and 8th gear. This resulted in increased line pressure and the shudder does not occur. There is also a table that affects ramp rate of pressure based on slip but I did not need to touch that table.

I'm not saying don't go to the dealer and let them flush/replace the TC per the TSB but if you don't want to go that route it appears it can be mitigated via the TCM calibration.

I thought I'd share for the benefit of the community.

Tim

Thanks for the info, does moving those tables can affect the life of the trabsmission?

[KingLT1]

No if anything it will pro long the life of the transmission. Slipping causes heat which eats up clutches.

[Camaro1061]

Originally Posted by KingLT1

No if anything it will pro long the life of the transmission. Slipping causes heat which eats up clutches.

Thanks for the reply, do you think that with adjusting the shift firmness with a diablosport tuner will help with the shuddering?

[KingLT1]

No because the shudder does not occur on shifts. It usually happens when cruising around 1500 RPM and or in/out of AFM.

[parbreak]

OK, I just had my TCM unlocked and we will be doing some other mods. Should I tell my tuner to ZERO out all slip in 7th and 8th gear? Anything else I should tell him regarding the shudder problem and tuning solutions?