Worked at GM dealers since the Allison came out. Have seen ZERO problems.

I wonder if Mahk is in on this?

TCC Shudder and New Mobil 1 Fluid Exchange

January 31, 2019

A new transmission fluid exchange procedure and a new formula of Mobil 1 Synthetic LV ATF HP transmission fluid have been released to address torque converter clutch (TCC) shudder conditions on 8L45 and 8L90 8-speed automatic transmissions (RPOs M5N, M5T, M5U, M5X) in some 2015-2017 Escalade, Yukon; 2015-2018 Silverado, Sierra; 2015-2019 Corvette; 2016-2018 CT6; 2016-2019 ATS, CTS, Camaro; and 2017-2019 Colorado and Canyon models.

The new fluid exchange procedure requires the use of the DT-45096 TransFlow Cooler Flush Machine and DT-52263 Transmission Fluid Exchange Tool Kit. (Fig. 10) The tool kit began shipping to dealerships at no charge in late January 2019. All GM dealerships should receive the tool kits by the end of March 2019.

Shudder Test

The new service procedure addresses shake and/or shudder conditions during light throttle acceleration between 25 and 80 MPH (40 and 128 KM/H) at a steady speed when the transmission is not shifting gears. To ensure TCC shudder is diagnosed correctly, drive the vehicle on a smooth road with transmission sump temperature between 122°F (50°C) – 158°F (70°C). Constant throttle input on a smooth grade is needed.

A shudder condition may also be a chuggle, surge or vibration condition. Use GDS 2 or the CH-51450 PicoScope to confirm that the concern is TCC shudder and not a tire/wheel vibration or a driveline vibration, for example. A screen print from GDS 2 or the PicoScope showing the TCC shudder event must be attached to the Repair Order hard copy.

If TCC shudder is present, a vibration peak will appear within +/- 2 Hz of the frequency listed in Bulletin #18-NA-355. Refer to the bulletin for additional information, including required shudder test conditions for each vehicle being diagnosed as well as the fluid exchange procedures.

Fluid Exchange

The TCC shudder condition is related to moisture content in the transmission fluid. The current fluid tends to be hydroscopic, or absorbs moisture, which increases the chance of TCC shudder. There are three different fluid exchange procedures to follow, depending on vehicle application, so that an acceptable concentration of the new HP fluid is achieved in the transmission.

The new Mobil 1 Synthetic LV ATF HP transmission fluid is now available to U.S. dealerships through your local GM Oil Distributor. The new Mobil 1 Synthetic LV ATF HP transmission fluid is available in quart bottles (GM Part Number 19417577) and, for a limited time, in 55-gallon drums (GM Part Number 19417904) in most locations. Drum production ended in January 2019. The GM part numbers are not on the product.

The Mobil 1 Synthetic LV ATF HP fluid and the required tool kit will be available to all Canadian dealerships by the end of March 2019. GM Part Numbers for 0.946 liter bottles will be provided at that time.

TIP: Mobil 1 Synthetic LV ATF HP transmission fluid is required for all 8-speed transmission repairs regardless of the repair being completed.

Quart bottles, which can be identified by a new blue banner across the front of the bottle (Fig. 12), will be limited to 20 cases/120 quarts per dealer per week during the initial launch of the new product. The new bottles also feature the HP license number J-62120 on the back label.

Metal shavings=seriously not good.
Hopefully the fluid change works out for you.

why is the transmission in 8th gear at 35-45mph? Even if you had coasted down from 65mph, it should downshift somewhere in there, or immediately downshift once you press the gas pedal.

My bone stock xl work truck has the 10 speed. GM's crazy.

Low rpms = low engine load. Lock the converter and keep it in 8th to save the mpgs CAFE mandates.

Enough boomers cunted about the 6R80 Ford had us reprogramming the fucking things shipping them as "fixed" only to hear them bitch worse.

Know what the problem was?

Boomers trying to soak every last tenth of an MPG according to the dash, they were causing the trucks to hunt for gears.
Ecojunk, 5.0 didn't matter. 6.2 F1shittys didn't succumb to this issue.

I'd drive them just like I drive my truck.
Wide open throttle until desired speed, lift leaving barely any pressure on the pedal. Transmission shifted fine.

4R70s in crown vic cop cars and Econoline work vans?
I'd set the clutch gaps super tight.
Fuckers shifted like bracket cars but never once burnt another transmission.

The fault lies squarely with non driving cunts who want smooth shifts. PCM strategy is adaptive but preprogrammed parameters essentially slip shifts and duty cycle solenoids causing clutches to be "massaged" rather than "engaged".
Thus. Trans fluid Temps rise... friction material goes bye bye. Solenoids and valve bodies get clogged. Line pressure is reduced further. And eventually you wind up burning the pump up and/or planetary gear sets, (for the morons who can't come to a complete stop before shifting from reverse to drive and vice versa) bearings, clutches...

Want the problem solved? Raise the line pressure.
Don't bitch it shifts like a 1/4 mile car though
You want all the holding force you can get. Ramp that line pressure up.
Unless there's a fatal design flaw that can't be helped unless engineering redesigns said component.
Like reverse pistons in torqshifts behind 6.0s and 6.4s. 5R110.
I did alot of those.

Pick your poison boys.
Smooth shifts. Popped trannys.
Harsh shifts. Oem tranny to 200k+

If you have an 8 speed. Try running it in tow haul mode.
Or when the light turns green, that long skinny pedal on the right? Push it as hard as you can. Every time.

I have a 14 silverado. It's been issue free. Guys on GM truck forums cunt about hunting for gears, slipped shifts, harsh shifts violent down shifts when "cruising" at low speed...
I've yet to have any problem with mine...
Ask what their age/driving habits are.
Guarantee boomers and pussyfooters.

Same with what happened when Ford first put 6 speeds in F150s.

MUH TRANNY IS GONNA FALL OUT OF THIS THING!
I SPENT 60K ON A HUNK UH SHIT! MUH RETIREMENTZ!

I promise half the PCM updates I performed weren't needed. It was all driver habit.
Go for a ride with the customer as I was never able to duplicate the concern.
Yup. Coming up a hill. Grandpa has it going the speed limit turning 1200 rpm... kathunk heard and rocked back in my seat as it went from having the torque converter locked in 6th, down shifted to 3rd or 4th...

I'd go up that same hill differently though. Half throttle halfway up crest doing 70
Boomers? Barely touch the pedal. Muh gas mileage.

Then don't buy a truck bitch. Buy a little clown car... Oh wait... your barely able to fit in the lazy boy recliner sized captains chair. You've got shit spilling over each side of you. You might grab a sheet of plywood or two once a year, maybe tow the boat 4 times during the summer. I forgot. You absolutely needed a truck...

The best were the assholes that bought king ranch super duties This thing rides like a damn lumber wagon!

Well... it's a 1 ton truck. The fuck were you expecting?

Ford and GMs biggest errors? That were self inflicted...
Getting rid of the Lincoln Town car and Cadillac Deville...

95% of warranty tickets that landed on my tool box were buyers remorse from MPG conscious boomers. Trying to save a buck everywhere they could. Including oil changes. Top end ticking? Lacks power? Check engine light on? 5.4 3v?
Mile guard filter? Jiffy lube filter? Yup.
Oh you gone pay today.

I still have that SSM in a 3 ring binder where FoMoCo told us to deny warranty coverage for phasers and solenoids if an aftermarket oil filter and/or over oil change intervals.

But yes. Ford and GM really fucked up getting rid of full sized sedans. That same pain in the ass customer went from baby carriages with leather sun roofs etc to half ton pickups/suvs/3/4+ fully loaded crew cab pickups.

That generation wants smooth soft to the point you can't even tell the transmission has shifted-shifts.
That generation wants big comfy seats with the softest smoothest riding chassis under it-air ride.
That generation had the $ for 50k+ daily driven vehicles-partially why a shit tier anything is 30k+
Obama era regulations.
Planned obsolescence.

Hence why we can't have nice things...

But yeah. Keep pushing for smooth shifts. Let me know how that works with wimpy line pressure.
Most will be on their 2nd or 3rd transmission or have traded in.
Mine will still be on its original transmission with just filter and fluid changes. Just like my last truck. And the truck before that. And the truck before that...

BIG TRUCKS NEED BIG LINE PRESSURE

Attached File

WTF are you saying here?

No one short of a NASCAR driver drives with the peddle on the floor just to get up to speed. I don’t care about MPG, I care about not driving like an Ahole. It’s also nice not to replace break pads at every other oil change.

Can you give the TLDR version of your rant? It’s like you know what your talking about but your communication skills make it hard to follow.

I have an ‘18 Silverado Z71 crew can with the 6 speed, it had only 6k miles. What should I be doing?

The only thing I notice is hard shifting sometimes when I’m slowing down around 20mph.

And yes I only really need a truck during hunting season and every time I go to Home Depot.

This part I do not understand. Is Grandpa using paddle shifters to keep it in 6th at 1200rpms? If he ain’t controlling the gear it’s in, how is that his fault?

Is “must floor throttle and take hills at 70mph” really what you consider “functioning as designed?”

Like all the GM class actions, lawyers will get millions, owners will get a coupon for $1500 off a new vehicle.

Been there.  

Short answer: gas mileage

No metal in ours but tech said it’s common. They had the car for a few days waiting for the new fluid mentioned in the post above about the latest TSB. Loaner was a 3.0tt CT6 so she didn’t mind.

At least grandpa will fall off the running board and break a hip in the snowy winter so that truck gets passed down to his family.

Kharn

This.  Quit buying autos that don't say allison on the plate.  The zl1 video with it hammering through the 10 speed does sound kind of amazing I'll admit.

Or learn how to tune a tcm and ramp line pressure up for shifts and down after  clutches have applied. Works for allison and they hold ALOT more torque than the 6 or 10 speed was built to handle.

Normal duty on an allison, torqueshift or aisin would paint the road with 6 or 10 speed guts.  It's about sq inches of clutch and line pressure. They know how to build a decent trans, they know friction coefficients of various clutches at various pressures. Auto trans aren't black magic. They are shooting for good enough when their customers are looking for better than required.

Allison built that reputation through over achievement, when they were owned by GM.   Sadly the idea that anyone can build a bridge that stands...but it takes an engineer to build a bridge that barely stands...is alive and well in the auto industry.

The Cherokee uses a ZF 9 speed front wheel drive and there have been a lot of complaints. The Grand Cherokee gets the same 8 speed ZF as the trucks and rear drive cars. People usually like those although I did not care for the 1-2 shift logic combined with lots of turbo lag in my ecodiesel.

So what you're telling me is that my 4l60e is cool?!

I've never had an auto that had over 4 forward speeds.  I imagine there's a lot of gear hunting going on...

My Escalade has been in the shop twice about the vibrations.

This.  I am a manual transmission guy but I have one in my Ram and it is awesome for an automatic.

My ‘17 Tahoe has a slight shudder in the lower gears, first run of the day

I have 8 speed in my 15 Sierra and I have the problems they are talking about.  The trans has already been rebuilt at 70K and it is better  than it was but it still shifts like shit and slams at times and other times at low speed the torque converter clutch will stick and then pop loose.   I lost about 5 mpg after the trans rebuild also.

Jeep Cherokee did not use the ZF 8HP it used the front wheel drive 9 speed also by ZF.

The ZF 9HP speed front wheel drive had early issues.

the ZF 8HP 8 speed is bulletproof...

Is that counting the billions that Obama stiffed their creditors or not?

ehhh, DYMOS and Powertech make a fine transmission for personal passenger vehicles, but for the really big stuff Allison all the way

our 8 speeds have no issue

The ol lady has had 3 clutch packs put in her focus, it's at 70k now and in need of another.

I have no desire to in any CVS transmission in any make. I'm GM all the way, never had issues, but my last vehicle purchased new was in 01, actually two that year. Both still rock solid.

The fuck is that thing?

No. We're not.  4l60s are never cool.  4l80s can be made cool. 4l60s can be made adequate....barely.

Anyone who's dumb enough to believe that an automatic transmission rebuild costs $8000 deserves every single inch of fucking they're about to receive.  That's just stupidity on parade.  

Time to bring back the manual transmission

I have an 8 speed in a Colorado that's been perfect. Shifts nice. I better knock on some wood.

Looking for the nearest Ford dealership and seeing what they'll give you on trade.

Sadly most people that own vehicles have no concept of what things should cost. Especially mystical slush boxes.  Ripems go in and get magically multiplied by liquid and unicorn farts.

True.  Kinda like the moron who started the thread a few days ago claiming that the "stealership" quoted his dad something like $5400 to change a driveshaft.  I've been around the automotive business all of my 49 years and owned my own shop for the last 23, and I've seen damn near every kind of BS known to mankind go down.  One thing I've never seen though, is anyone so brazen to try and charge $5400 to replace a driveshaft.  Having said that, if you're too fucking lazy to crawl under your car and see that there's a bungee cord wrapped around your driveshaft (hypothetically, of course) then maybe you deserve to pay $5400 for it.  @Keekleberrys  

My 18 silverado shifts smooth, no problems here,  I don’t drive like a grandpa though. I think these trucks don’t like being at low rpms when gears are changing

Moms around here still buy Yukons, suburbans, and escalades as fast as the dealerships can sell them.

Had it done, doesn't fix it. '17 6.2 with 8 speed.

General Motors CEO Mary Barra was aware of the ignition switch defect and the fact people were dying and did not initiate a recall.

Attached File

I agree.
Definitely a bean counter move to not.

Let me guess: it was in an FCA car?

The manufacturers still have to come up with the programming for them.

I dont understand,  GM has allways had defective transmissions, used excessive oil and dashboards would crack.

Why is there a lawsuit now?

I'm no transmission expert...but I've been saying this for years!

Laughs in TorqShift 6R140

How much was that payout?

Did GM source Gen 3 Tacoma transmissions?

Yep.

That’s why I refuse to buy one. Toyota really F’d up the 3rd gen.

That is why I bought one of the last 2015's remaining. Got a great deal on it to boot.

Wanted the 4.0 and the A750 transmission.

It's kind of hard to believe that engineers are allowing a target of soft shifting to lower lifespans and produce other gremlins...

You'd think that they'd shift the clutch packs appropriately, and let a computer controlled torque converter be the buffer.  This is an advantage of the 'slush' in slush box after all.  This would make sense as the cause of the 'shudder' that some complain about, but having it would seem to increase life, rather than decrease it which is what some of you are saying.

I have a ‘16 Silverado with the 8 speed.  I bought it used with 54k on the clock.
I had the vibration.  They did a flush that didn’t work and then a converter replacement.  
There are times I’m not sure there’s not something going on...
I will check into this.

If the fluid change doesn’t work they change the converter.
It seemed to have fixed mine.
The wrong spec fluid was ordered initially.  Seems like that would have been corrected a long time ago and not an issue any more.