Torque converter shudder/RPM flair

[lba0213]

Wanted to put this out there for you guys. My 2015 6.2 silverado with the 8 speed has been suffering from serious shudder for quite a while now. When I first took it to the dealership, GM had not yet come up with and updated torque converter for the fix. WELL apperently they have now, SOOO, I had the converter replaced last week.

 

Guess what........it didnt do a damn thing, as a matter of fact, it might be worse now. Just thought Id let you guys know. Im curious to know if this converter swap has helped any of your trucks suffering from this issue. My truck literal shudders on every other gear shift and anytime under light throttle at any speed. The only way to stop it is to go in to manual and change gears to get the RPMs above 2k.

[Fishbait]

I had mine replaced on my 2015 6.2 around 2500 miles ago.It made a world of difference. No more flairs,hard shifts or shudders.I still get a random clunk but nowhere near as frequently as before the swap.

[Gihan Indika]

it will be a normal condition after doing a repair related to transmission! to overcome this you have to try learn the shift valves and decelerating mode! may be helpful. here are the steps

select a road that with less traffic and turns

start from 0 accelerate to 100. once reached let decelerate itself with slightly applying brakes to 0 again accelerate

continue this step 15 times and see is there any difference if there is not we can go learning solenoid valves one by one

[Gihan Indika]

it will be a normal condition after doing a repair related to transmission! to overcome this you have to try learn the shift valves and decelerating mode! may be helpful. here are the steps

select a road that with less traffic and turns

start from 0 accelerate to 100. once reached let decelerate itself with slightly applying brakes to 0 again accelerate

continue this step 15 times and see is there any difference if there is not we can go learning solenoid valves one by one

Note: This sequence is MY 2015 specific and varies from MY 2016. The following adaptive learning procedure was developed to further learn clutch pressures and volumes required for specific shifts. To expedite the learning process, it is recommended to utilize a road with minimal traffic volume that has as smooth and level surface as possible.

To Learn C1 (For 6-7 or 3-1 Shift)

1. Pressure & Volume Learns:

Note: It is recommended to utilize a road with a speed limit between of 30-45 mph (48-72 km/h) for this procedure.

Shift the transmission into 6th gear with the PRNDM in the M position. Obtain an engine speed between 1000 and 1600 rpm. Maintain this condition for a total of about 5 miles (8 km). Cruise control may be used and has been found to result in faster learning of the clutch values

To Learn C2 (For 6-5 Shift)

1. Pressure Learn:

   Note: : It is recommended to utilize a road with a speed limit 40-45 mph (64-72 km/h) for this procedure.

   • Perform 15 normal mode 6-5 coast down shifts (zero/light brake) to learn the C2 Return Spring pressure.
2. Volume Learns:
   • Shift the transmission into 8th gear with the PRNDM in the M position. Obtain an engine speed between 1000 and 1750 rpm. Maintain this condition for a total of about 5 miles (8 km). Cruise control may be used and has been found to result in faster learning of the clutch values

To Learn C3 (For 2-3, 4-5, or N-D Shift)

1. Pressure Learns:
   • Perform 15 normal mode 8-7 coast down shifts (zero/light brake) to learn the C3 Return Spring.
2. Volume Learns

   Note: It is recommended to utilize a road within a Business Park or similar area, where it is safe to drive at very slow speeds of approximately 5-25 mph (8-40 km/h).

   • Shift the transmission into 4th gear with the PRNDM in the M position. Start a slow acceleration at about 1,100 rpm and maintain the slow acceleration until you reach about 1,500 rpm. Once you reach 1,500 rpm, go back down to 1,100 rpm and repeat the slow acceleration up to 1,500 rpm. Repeat this 15 times.

     Important: If rpm’s drop below 1,100 rpm vehicle will downshift into M3 and pause learning process. If this occurs please accelerate and tap back into M4 and start counting from where you left off. Additionally while watching the tachometer and applying a constant throttle. You’ll see tachometer rpm’s increase rapidly and then once adapt process starts rpm ramp rate will decrease and you’ll feel the vehicle having a tie-up type feel.

To Learn C4 (For 1-2, 5-6, or 7-8 Shift)

1. Pressure & Volume Learns:

• Shift the transmission into 7th gear with the PRNDM in the M position. Obtain an engine speed between 1000 and 1750 rpm. Maintain this condition for a total of about 5 miles (8 km). Cruise control may be used and has been found to result in faster learning of the clutch values

To Learn C5 (For 3-4 or N-R Shift)

1. Pressure & Volume Learns:

   Note: It is recommended to utilize a road within a Business Park or similar area, where it is safe to drive at very slow speeds of approximately 5-25 mph (8-40 km/h).

• Shift the transmission into 3rd gear with the PRNDM in the M position. Start a slow acceleration at about 1000 rpm and maintain the slow acceleration until you reach about 2500 rpm. Once you reach 2500 rpm, go back down to 1000 rpm and repeat the slow acceleration up to 2500 rpm. Repeat this 15 times.

  Important: While watching the tachometer and applying a constant throttle. You’ll see tachometer rpm’s increase rapidly and then once adapt process starts rpm ramp rate will decrease and you’ll feel the vehicle having a tie-up type feel.

Power Downshift Adaptive Learning:

Starting with the vehicle operation in 8th gear, slowly apply pressure to the accelerator pedal until downshift occurs. Repeat as necessary in each gear (8, 7, 6, 5, 4, 3 and 2).

 

• This procedure will learn the off-going clutch adapts for desired power downshift control.

[lba0213]

ummmmm.....ok?

[Dnt]

I just did this and it worked perfectly except that I got 16 speeding tickets....hahahaha

[truckguy82]

it will be a normal condition after doing a repair related to transmission! to overcome this you have to try learn the shift valves and decelerating mode! may be helpful. here are the steps

select a road that with less traffic and turns

start from 0 accelerate to 100. once reached let decelerate itself with slightly applying brakes to 0 again accelerate

continue this step 15 times and see is there any difference if there is not we can go learning solenoid valves one by one

I'm assuming you meant km/h?

[Gihan Indika]

I'm assuming you meant km/h?

yes of course! follow the steps on 1st quote

[shadowmn]

This is good information, but it's all complete BS at the same time because GM should do this from the factory so we don't have to deal with this crap and have a nice running truck from day one!

[HawkeyeSierra]

it will be a normal condition after doing a repair related to transmission! to overcome this you have to try learn the shift valves and decelerating mode! may be helpful. here are the steps

select a road that with less traffic and turns

start from 0 accelerate to 100. once reached let decelerate itself with slightly applying brakes to 0 again accelerate

continue this step 15 times and see is there any difference if there is not we can go learning solenoid valves one by one

You're kidding right? I've heard a lot of excuses for speeding, but never this one.

[truckguy82]

You're kidding right? I've heard a lot of excuses for speeding, but never this one.

It was a bit of a d-bag move for him not to recognize this is a 99% united states forum and we don't use km/h. Who knows how many people are going to read that and go 0-100mph-0 15 times.

[HawkeyeSierra]

It was a bit of a d-bag move for him not to recognize this is a 99% united states forum and we don't use km/h. Who knows how many people are going to read that and go 0-100mph-0 15 times.

Oh, ha! I didn't even notice that. Good catch. That does make a difference.

 

Still, I've never heard any advice remotely like his. Is it legit??