While my 17 GS is in winter storage. I decided to pull Range Device out of GS in November and install it in my 18 GMC Sierra A8. As a test. Last winter I noticed hard shifting in cold temps outside a lot more than my previous 14 Sierra A6 . Now with Range Device in 18 Sierra trucks shifts so much smoother when cold outside and seem that engine runs much smoother also. Neither vehicle had the feeling of rumble stripes Only the Sierra had hard shifting in cold temps outside. GS no symptoms as of yet. Originally I bought Range Device as a preventative measure peace of mind thing. After this 2 1/2 month test I will be buying second Range Device and be checking into if dealer will do Triple Flush without symptoms just with me asking .They do know about hard shifting and has been documented on GMC Sierra.It’s with a try ! Just thought I doss this little test out to forum members .Dave

 

Thanks for sharing.

 

The latest TSB states dealer to flush based on customers complaint...no need to verify complaint.

 

Hopefully a triple flush would solve the shifting problem. Interesting that the Range Device helps so much.

 

So your range device which keeps your truck in V8 mode only is making your engine run smoother and making your transmission shift better? I find that hard to believe.

 

Correct device keeping it out of V4 seems to have removed slight vibration in engine and giving me smoother shifts.
I notice smoother engine and tranny down shifting when Truck is decelerating . Appears to me that with Range Device blocking V4 mode it’s helping eliminate hard down shifting and engine roughness / vibration during deceleration by blocking V4 mode.
I’m thinking cold outside temps had little or nothing to to do with problem was more a entering V4 mode problem.

 

Yea new TSB states if customer complains just change fluid. This is what I did, SM said yea bring it in and we will drive it and I showed him the TSB and he said ok bring it in and we will change fluid. I did this about 180 miles ago and didn't have shudder issues before but did as a precaution and tranny shifts smoother.

 

I have to agree with the positive change in shifting using the Range. My GS never experienced the rumble strip issue so I bought the Range as a preventative measure. However it did shift very rough/hard from 1 to 2 especially when cold. The Range really smoothed that out and the shift feels normal now. I've had the Range for about 2 years with no issues. I also agree with the flush comments, I simply asked about it and my dealer did it no questions asked.

 

How much are dealerships charging for a triple flush?

 

No charge.

 

Hi do you have the TBS number that states that? thanks

 

 

TSB 18-NA-355 First page states if customer complains no further testing is required, change fluid. This is copied from first page of TSB, see bolded text in red.

Service Bulletin Bulletin No.: 18-NA-355
Date: August, 2019
TECHNICAL
Subject: Shake and/or Shudder During Light Throttle Acceleration Between 25 and 80 MPH
(40 and 128 KM/H) at Steady Speed
Attention: This Bulletin only applies to vehicles sold in the U.S., Canada and Middle East
Operations (MEO). Mexico and Export Regions should follow Bulletin 19-NA-018.
Brand: Model:
Model Year: Date Breakpoint: Engine:
(2.0L, 2.5L, 3.0L,
3.6L, 5.3L, 6.2L)
Transmission:
(8L45, 8L90
from to from to Automatic)
Cadillac
ATS
2016 2019
SOP
Feb.
1, 2019
LCV, LGX, LTG,
LT4, LF4 M5N, M5T, M5U
CTS
CT6 2016 2018
EOP
LGX, LGW, LTG M5N, M5X
Escalade
Models 2015 2017 L86 M5U
Chevrolet
Camaro 2016 2019 Feb.
1, 2019 LGX, LTG, LT1 M5T, M5U
Colorado 2017 2019 March
1, 2019 LGZ M5T
Corvette 2015 2019 Feb.
1, 2019 LT1, LT4 M5U
Silverado
Models 2015 2018 EOP L83, L86, L8B M5U, M5X
GMC
Canyon 2017 2019 March
1, 2019 LGZ M5T
Sierra
Models 2015 2018
EOP
L83, L86, L8B M5U, M5X
Yukon
Models 2015 2017 L86 M5U
Involved Region or Country United States, Canada, Middle East Operations (MEO)
Condition
Some customers may comment that their vehicle is experiencing a shake and/or shudder
during light throttle acceleration between 25 and 80 mph (40 and 128 km/h) steady state
driving when transmission is not actively shifting gears.
⇒ The condition may be described as if they are driving over rumble strips or a
concrete road surface with rough expansion joints.
Cause This condition may be due to Torque Converter Clutch (TCC) Shudder.
Correction
Vehicles that are presented with TCC shudder should have the appropriate fluid
exchange procedure completed. Diagnosis beyond the customer compliant is not
required if vehicle was built prior to production dates indicated above.
For vehicles built after the production dates listed above.
⇒ If a customer presents a vehicle with a similar complaint, follow normal SI
diagnostics. These vehicles are already equipped with the latest HP fluid.

 

Love the Range.

Well worth the money.

 

See the attached.

 

Thanks again for posting this information

 

bjones7131, Thanks for posting I have been looking for this for a while. I want to get this done as a precaution on my 17 GS and 18 GMC Sierra. Thanks again Dave

 

Good luck with that! I've contacted 5 dealers in the greater Phoenix and Tucson areas about doing the flush and none will do it without a diagnosis, even after I presented them with the TSB and pointed out the phrase - "Vehicles that are presented with TCC shudder should have the appropriate fluid exchange procedure completed. Diagnosis beyond the customer compliant is not required."

 

Well that sucks . . . . . even when presented with the TSB?



Ridiculous.

 

Very odd. The dealers get paid for the work and should have no objection following the TSB.