GM guys...blow trannies

[Bigbore500r]

This thread makes me smile.

Anything newer than 1999 makes you smile

 

[rivermobster]

Anything OLDER than 1999 makes you smile

Fixed it for ya

 

[hallett3]

I installed this thermostat bypass on my newly rebuilt trans. Easy install.

GM 6L45 6L50 6L80 8L90 SURE-COOL Cooler Flow System by Superior (2014-UP)

Superior's STL010 6L80E 6L90E SURE-COOL Cooler System is a recommended upgraded during any rebuild or as preventative maintenance to any HD GM truck or motorhome. Easy to install, save yourself or your customer thousands of dollars down the line.

globaltransmissionparts.com

Did my 2015 Silverado and trans temp is consistent 160 degrees in 100+ Outside temps. Plus I have deleted the AFM which helps out on no more 8 to 4 cylinders which is hard on the torque converter. These new trucks are junk and we just have to make them better. Kinda sucks when you pay so much for them.

 

[Cobalt232]

My kids 2018 was just starting to shudder at 45k. Then it got totaled. I really like our new 10-speeds in his Trail Boss and my ZR2. Hope they hold up.

 

[pkrrvr619]

Sucks ass, but you gotta replace the converter before it fails.

I started a thread about it…

6L80e issues / torque converter

I’m pushing 80k miles on my ‘15 Silverado 5.3 Noticed two big slips recently, I think my torque converter is giving up. Truck was at a slow roll, I gave it some throttle, revs went right to the limiter and truck didn’t move. I let off the throttle, felt it engage second, and then performed...

www.riverdavesplace.com

So just replacing the bypass valve wont solve the issue alone?

 

[pronstar]

So just replacing the bypass valve wont solve the issue alone?

I dunno anything about a bypass on the tranny…but the main issue is spelled out in the sonnax article linked above. It’s a clutch mating surface issue - it distorts

It’s not easy dropping coin on a seemingly OK transmission…but if you wait until it fails, then the repair cost triples.

The only reason why I haven’t replaced the converter in our suburban, is because it’s still under warranty.

If the converter doesn’t shit the bed under warranty, then I’m replacing the converter immediately after the warranty ends.

IMHO these are otherwise pretty good vehicles that have a fucking lame fail point or two (add cylinder deactivation and AC condensers to the list) that’s so typical of GM.

 

[CarolynandBob]

So is the fix to change that tbv valve or just wait for it to blow up?

Wife has a 2016 Yukon id like to keep in one piece.

I don't know. Mine happened summer of 21. They said they should replace whole trans, but couldn't get one. They replaced 96 parts in it and it took 2 months. Got it back in September and went to our Florida place. Wasn't sure it was going to make it. Going down a hill it seamed like it couldn't figure out what gear to stay in. Was weird. Made it to Sarasota and took to dealer. They had it 4 days and said nothing is wrong with it. 4 days later I traded it. Will never buy a GM vehicle again.

 

[sml]

I will never own another gm vehicle as long as i live after my last experience.

Had a ‘17 express van 2500. 6.0 six speed. Bought it with 2 miles on it. Biggest pos ever since day one. The hard shifting and always hunting trans was about 6th on the list of things. Was always told it was operating as normal.

Couldn’t lemon law it in my state (commercial vehicle) so instead had to sue for breach of warranty contract. Gm agreed to not black ball the vin and I got half the money back. It sat for a couple months at the dealer, then sat in the driveway for a couple years after everything was “fixed”. traded it in for more than i paid for it 3 months ago.

 

[pkrrvr619]

I dunno anything about a bypass on the tranny…but the main issue is spelled out in the sonnax article linked above. It’s a clutch mating surface issue - it distorts

It’s not easy dropping coin on a seemingly OK transmission…but if you wait until it fails, then the repair cost triples.

The only reason why I haven’t replaced the converter in our suburban, is because it’s still under warranty.

If the converter doesn’t shit the bed under warranty, then I’m replacing the converter immediately after the warranty ends.

IMHO these are otherwise pretty good vehicles that have a fucking lame fail point or two (add cylinder deactivation and AC condensers to the list) that’s so typical of GM.

What was the repair cost for the converter?

 

[pronstar]

What was the repair cost for the converter?

Parts and labor were around $1400 IIRC
Converter cost can vary depending on which one you go with.

 

[j21black]

 

[bk2drvr]

Here is what to look for if you pull your pan. I pulled the pan the second I felt something weird and then the "oh shittttttt moment"
.

 

[69hondo]

Did my 2015 Silverado and trans temp is consistent 160 degrees in 100+ Outside temps. Plus I have deleted the AFM which helps out on no more 8 to 4 cylinders which is hard on the torque converter. These new trucks are junk and we just have to make them better. Kinda sucks when you pay so much for them.

Where does this install at? Not much description in the details.

 

[EmpirE231]

Same with me. I'm so f'n pissed right now. Got gas in Beaumont at chevron and apparently the diesel was "Bio Diesel". My brand new truck been at the dealer for 2 weeks with an engine knock and they won't cover it.

If I get shafted on this it will be the last GM product Ill ever buy and I've owned over 30.

That's crazy! is there some sort of warning or notice not to use bio diesel in the truck?

re: the trans... anyone know if the issue is resolved with the newer 10 speeds?

 

[stingray11]

Chevy's have been blowing Tranny's since the 1970 nothing new about that they're junk.

 

[bk2drvr]

Where does this install at? Not much description in the details.

It’s on the side of the trans bell housing. I think I have a picture of it off.

 

[bk2drvr]

Here ya go. It’s where the trans cooling lines go in/out to the radiator. If you have snap ring players you can do the install.

 

[EmpirE231]

Chevy's have been blowing Tranny's since the 1970 nothing new about that they're junk.

got 190K miles on the trans with my 2005 1500 w/ 5.3 before a trans rebuild and 220K miles on the motor before lifters started ticking.... If that is junk, then junk is pretty good!

 

[69hondo]

Here ya go. It’s where the trans cooling lines go in/out to the radiator. If you have snap ring players you can do the install.

View attachment 1182247 View attachment 1182248 View attachment 1182249

Thank you

 

[racektm]

got 190K miles on the trans with my 2005 1500 w/ 5.3 before a trans rebuild and 220K miles on the motor before lifters started ticking.... If that is junk, then junk is pretty good!

229K on my 2012, 1500 w/5.3 all original, no trans issues, no ticking.... Knock on wood!

 

[77charger]

I know i told my experience with my 04 and 4l80but had a 13 2500hd with 6.0 for a work truck which can be abused at times that truck had 310k miles on it with 6l90 trans.Trans had issues at 255k think it was torque converter as it made noise at times then quiet.owner just replaced it due to miles.But engine was great still solid at 310k never had a check engine light on the entire time and only issues were radiator went out about 250k a water pump about +- 10k of radiator,ac went out about 285k besides that nothing else.

Have no doubts that engine will go 400k plus. dont know where the 5.3 went wrong AFM? or modern fuel saving tech?

 

[DarkHorseRacing]

Well there’s a large aftermarket contingent that makes them better. So if you drive a bow tie or related, you should factor getting the trans beefed up as part of your fight to get the truck for as cheap as possible. You know you need to them sink the savings into a rebuilt/beefed up trans even if it’s under warranty.

 

[boatpi]

I have not purchased a GM product since my 1990 Silverado 1500. Water pump at 800 miles, shifter fell apart at 30,000, and alternator at 16,000 miles. Had a Saturn Vue, decent vehicle, entire ac took a shit at 80,000, my ac guy said I was lucky and GM designs the compressor with a 75k life span. He is making $$$ all the time off of that.

So I have had maybe 15 vehicles since 1990, name the make, never any issue with a component part except a Kia that was under warranty.

 

[jet496]

I have around 10 Chevy Silverados & sold about the same amount once they hit 200,000 miles. All problem free. I switched from Fords because they were guaranteed to have a tranny problem by 80k miles.

But, we do have a 2017, F350 with 100k problem free miles & it's a stout fucking truck. I think we'll look at Fords again this year.

 

[RCDave]

GM guys blow TRANNIES???

Lol

 

[pronstar]

GM guys blow TRANNIES???

Lol

Sometimes the tranny gets blown.
Sometimes the tranny does the blowing.

 

[Member: 71]

Where does this install at? Not much description in the details.

Had my fair share of blown up transmissions and want to prolong the process on my 2017 Yukon.
Found this on YouTube as I'm interested. Looks easy if you got a lift.

 

[pwerwagn]

Does anyone know why the TSB excludes Escalades?

Is the 8L90 in the 15-17 Escalade different for some reason? I know the thread is regarding the 6L but the tsb says 6.2 trucks too. I assume those have the 8L?

Reason I ask is my wife has an 08 Escalade with 210k miles. We want to get something newer and I’m trying to figure out what vehicle is my best gamble.

 

[pronstar]

6L80 uses the JMBX converter
8L90 uses a different converter IIRC

 

[TPC]

GM offering the Allison with their gas engines in’24.

 

[Waterjunky]

GM offering their normal transmissions now with the Allison nameplate on their gas engines in’24.

Fixed this for you.....

 

[rivrrts429]

On my 2019 1500 5.3 I’m on my second trans and now second set of lifters. Both trans and lifters are acting up again. It’s just shy of 60k miles. Worst truck I’ve ever driven.

 

[Waterjunky]

Both the 3.5 and 10 speed in my 17 F150 have been absolutely flawless. Best truck I ever owned.

That said, I only have about 40k on the clock. Time will tell.

 

[76 Hondo]

OK, my 2017 Sierra tranny out at 73000 now at 109,000 the lifters are making noise! Say I want to keep the truck who can bulletproof trans? Do I change the lifters before it takes out the 5.3?

 

[pwerwagn]

OK, my 2017 Sierra tranny out at 73000 now at 109,000 the lifters are making noise! Say I want to keep the truck who can bulletproof trans? Do I change the lifters before it takes out the 5.3?

That’s sorta the same question I have. What do you do to these things to keep them alive? Is the 8l90 good? Do you have to do afm/dod delete on the newer 6.2’s? Our 08 doesn’t have it and is still running good.

 

[DarkHorseRacing]

You’re giving up a major portion of your fuel economy with an AFM delete. If you just keep your oil clean you shouldn’t have any issues with that system.

 

[GRADS]

After seeing the title, this thread was a real let down.

 

[pwerwagn]

You’re giving up a major portion of your fuel economy with an AFM delete. If you just keep your oil clean you shouldn’t have any issues with that system.

That’s good to know. It’s probably a crapshoot buying used then.

In reading about the 8L90’s, it’s looks like they have all sorts of issues. Seems like some flush with Mobil 1 fluid is the latest fix. I was really looking at the 16/17’s, might have to just start looking for something non-GM maybe.

 

[Runs2rch]

That’s good to know. It’s probably a crapshoot buying used then.

In reading about the 8L90’s, it’s looks like they have all sorts of issues. Seems like some flush with Mobil 1 fluid is the latest fix. I was really looking at the 16/17’s, might have to just start looking for something non-GM maybe.

We have a 17 6.2 8l90. No issues. I change the oil every 5k. Switched to Mobil 1 in the trans at 30k. Have 38k now. Dex 6 was/is the issue in the 8l90.

Good used vehicles exist. Just finding an owner that knows and cares.

 

[spectra3279]

I'll stick with my 03 dodge 3500 manual 6 speed. So far the worst engine problem I have is the timing gear cover. It leaks and I can't get to the bolts behind the balancer and I can't pull it without pulling radiator.

 

[Bigbore500r]

After seeing the title, this thread was a real let down.

HOLY SHIT....HES BACK!

 

[Bigbore500r]

OK, my 2017 Sierra tranny out at 73000 now at 109,000 the lifters are making noise! Say I want to keep the truck who can bulletproof trans? Do I change the lifters before it takes out the 5.3?

Regarding the trans - If you had the trans rebuilt already, i'd just tune it and disable the AFM. Here's what needs to be changed:

1. Disable TC lockup in 2nd and 3rd gears
2. Disable AFM (this is the main culprit, as it constantly locks / unlocks the converter and "slips" it so you don't feel the 4cyl mode activate
3. Have the 190 degree trans cooler thermostat eliminated, as said before in this thread.

That will take care of the trans, you shouldn't have a converter issue once you do that since yours has been gone thru already not that long ago...

Regarding the lifters - are you sure its lifter noise? These direct injected motors make alot of clicking racket, the injection itself is pretty loud, and some are louder than others. If they are actually ticking - yes you absolutely must change them. If not, just turn AFM off as preventative measure

Let me know if you need a tuner resource to do this...

JH

 

[Dana757]

If it makes you feel any better it’s not just “GM” guys.



Merry Christmas everyone.

 

[pwerwagn]

We have a 17 6.2 8l90. No issues. I change the oil every 5k. Switched to Mobil 1 in the trans at 30k. Have 38k now. Dex 6 was/is the issue in the 8l90.

Good used vehicles exist. Just finding an owner that knows and cares.

That’s good to know and seems to agree with what I’ve read on the 8l90. Looks like the Mobil atf used in those is about 200$ to change. Is there any way to tell if it’s already been flushed with Mobil? Reading on forums it seems that most of the 8L’s should’ve probably been changed over by now. Most of the 16/17’s I’ve been finding have ~70k miles on them so I would assume if they don’t shudder during a test drive, it’s probably been changed.

Does the 8L have the 190 degree tstat as well?

 

[TPC]

Fixed this for you.....
TPC said:
GM offering their transmissions now built with Allison Spex on their gas engines in’24.

Fixed it for you

 

[TPC]

Blow out the radiator liquid cooling circuit plumbing or trans cooler with compressed air. It can very well be clogged with flotsham and jetsham.

 

[TPC]

Chevy's have been blowing Tranny's since the 1970 nothing new about that they're junk.

Compared to,,,,,,?

 

[stingray11]

The wife and I both have Tundras with well over 200,000 with 0 engine and tranny problems. My bud has a Toyota land cruiser with 480,000 and still original engine and trans. And I tow a 23' eliminator with twins and a truck camper with my tundra,it's whole life.

.