VERY well regarded local transmission guy who has been doing them for decades, and even has the dealerships sending them their stuff had a lot to say about the GM 6 speed transmissions that came in the half ton trucks of that era. He said it's the PROGRAMMING that kills them. He said they lock/unlock the converter in EVERY gear. It does it so much, that clutch in the converter wears out, sending trash throughout the trans. He said they usually last around 130k miles in our hilly area. He programs the transmission to only lock up 4th, 5th and 6th.... or just 5 and 6. Can't remember, but it was only the higher gears. I believe he was using HP Tuners to do it, and HP Tuners was charging him something like $25 for each one he did. With his modifications, they are said to have a MUCH longer service life. He does upgrades to everything he builds. He does a nice 4L60E. He did one of those in my 2005 truck. I described the problem, and he said it was the sprag. He said they came with either an SKF or Borg Warner sprag, and the SKF were bad and failed. The clutch drum was also a bit splayed out. He said he uses the BW sprag and a hardened drum/hub... and a few other tricks. Trans has been flawless. Guy knows his stuff.
My 2017 (6.2 w/8l90) went back under warranty several times for the "Silverado Shake". The first time it got the flush procedure....to no avail. The second time they replaced the internal wiring harness....to no avail. The last time they listened to me and replaced the torque converter. The shutter is caused be a faulty lock-up clutch design. The front of the torque converter is too thin and wears unevenly. Drive that truck and watch your scan tool. You'll actually see the lock-up engagement followed by the instant shutter. You can actually just watch the tach and see when it locks-up as well. The stock replacement converter the GM dealer put in mine lasted until it was out of warranty...LOL The only REAL fix is an aftermarket converter with the billet front and multi-disk lock-up clutch. You'll have to have the TCM unlocked so you can change the trans lock-up characteristics, line pressure, torque management, etc. Best of luck to ya. Maybe you'll have better results than I did.
Thanks I'm surprised that anticipating several transmission fluid drainings & refillings that there isn't a DRAIN PLUG "kit" to be installed ... ? COOP ...
I have often heard that flushing and replacing transmission fluid on high milage transmission. Day around 100,000 miles can cause problems. I have been working on cars as a hobby since the mid 1960's and am wondering if there is any truth to this. My present faily driver has just reached 100,000 and the dealer is calling for this service to be done. I've come to trust your judgement. Thanks
Not really. Most folks change their fluid after they notice the fluid looks really bad, or when experiencing other issues. At that point, the transmission is on borrowed time. But, they just replaced the fluid 5000 miles ago, so the fault was changing the fluid, not their own negligence.
For GM- I think it’s best to do a fluid exchange, not a flush. I know on the sixth and eight speeds, rebuilders are using the mobile 1 synthetic LV ATF HP “blue label”.
Thanks for the information. Actually struggling with this problem with a 2018 Chevy Impala currently ugh I am in Springfield ohio. Any shops that you recommend in the area?
@@midwesthustla02i did a drain n fill on my 16 ltz n added one tube of lubegard my shit still shuddering i did the drain n full 3 days ago i see u say one or two tubes…. Im thinkin add another tube??
@OGkevo1231 i had to add 3 tubes and now it only shudders uphill in overdrive....it was way worse before....I'll drive it for some miles and then change the fluid and filter again and add 2 more tubes....the problem is that we need to keep changing the fluid and add more tubes until the torque converter fluid is clean
if thats an 8 spd trans the flush will not fix it for a long period of time ,, sorry , that trans has a known shudder problem right from the factory , gm says its a failing torque converter , replace converter and its all good !!!?? until its out of warranty , then it needs a trans. well thats gms fix to get it out of warranty . that truck is probably gonna need a trans , with new cooler a new valve thats on the trans lines and a program !!! good luck maybe that flush will fix it long enough for the customer to drive it to a dealer and trade it in !!
GM trans tech here, the last iteration of fluid and the flush procedure has cured damn near every shudder I have had in an 8 spd. My wife’s car has 145k on it and hasn’t shuddered since the last design fluid was used over 100k miles ago. I have changed the fluid every 50k since and did a filter at 100k and have never seen another shudder. At some point converters might fail, but the last design Mobil 1 hp atf fix’s the shudder in most.
@@dickbrugh5562 yes if a trans is serviced on a regular basis and a full sythetic atf is used yes it will prolong its life without a doubt and help . But !!! Gm had i big problen with the 8 spd trans , its no secret , no mystery at all , almost all of them no matter the mileage have had a shudder issue /complaint and the fix per gm is flush trans and replace converter , but with that in mind , if a converter comes apart just replacing it and flushing is not going to fix the problem in the long term , metal has been sent through the trans and the pump , also why are they shuddering ??? Well programming , lack of maint, and overheating fluid , due to the thermal valve on the trans lines at the trans , required replacement with a reman unit ,huh why ??? They fail ! And starve the trans for fluid . I worked for a gm dealer as a tech for a short time , and seen trucks with low miles and high miles have trans issues with the 8spd , i also work for a trans shop for a long time and we would replace the 8spd gm trans constantly, until .. they went on national back order , why ? High failure rate at all mileage intervals . In short .. the gm 8spd in oem form is junk , an aftermarket reman unit from jasper is superior , and the problems fixed as long as the install instructions are followed ,correctly . I like to repair vehicles so the repair lasts , not band aided , a flush on a high mile trans with shifting / shuddering issues is just that a bandaid . Just enough to trade it in and walk away .
@@jeremyalbert2069 Did I mention I was a GM transmission tech for the last 15 yrs? Not trying to be an ass, but you’re not telling me anything I don’t already know. I build my own performance units for myself and friends on the side. About to build my buddies 6l80e after it shit the converter. Well versed in GM transmissions.
@@dickbrugh5562 Any suggestions on finding a local Transmission guy who knows 8L90s? The couple of independent shops I have been to have no experience with the 8-speed. Prefer to avoid the dealer, who's suggestion for pretty much every issue is to replace it (transmission, engine, etc).
Thank you Rich. You’re not just a good mechanic. You’re giving total service when you can! Cuddo’s
💯👍👊
Had it in my 2018 ATS. My solution was to trade it in on a new Toyota Highlander, and I never looked back!
VERY well regarded local transmission guy who has been doing them for decades, and even has the dealerships sending them their stuff had a lot to say about the GM 6 speed transmissions that came in the half ton trucks of that era. He said it's the PROGRAMMING that kills them. He said they lock/unlock the converter in EVERY gear. It does it so much, that clutch in the converter wears out, sending trash throughout the trans. He said they usually last around 130k miles in our hilly area. He programs the transmission to only lock up 4th, 5th and 6th.... or just 5 and 6. Can't remember, but it was only the higher gears. I believe he was using HP Tuners to do it, and HP Tuners was charging him something like $25 for each one he did. With his modifications, they are said to have a MUCH longer service life. He does upgrades to everything he builds. He does a nice 4L60E. He did one of those in my 2005 truck. I described the problem, and he said it was the sprag. He said they came with either an SKF or Borg Warner sprag, and the SKF were bad and failed. The clutch drum was also a bit splayed out. He said he uses the BW sprag and a hardened drum/hub... and a few other tricks. Trans has been flawless. Guy knows his stuff.
Thank you so much for making this comment. I have hp tuner for DOD deactivation, but im glad to know i can change this, too.
Yes, rebuilder in the Houston area deactivates lock up except in five and six and deactivates DOD/AFM. Extends the life and reliablility.
You’re a good man
Lived in Ohio all my life. Wish I lived a little closer. I would like to bring my vehicle to you guys. 🇺🇸👍
My 2017 (6.2 w/8l90) went back under warranty several times for the "Silverado Shake".
The first time it got the flush procedure....to no avail.
The second time they replaced the internal wiring harness....to no avail.
The last time they listened to me and replaced the torque converter. The shutter is caused be a faulty lock-up clutch design. The front of the torque converter is too thin and wears unevenly. Drive that truck and watch your scan tool. You'll actually see the lock-up engagement followed by the instant shutter. You can actually just watch the tach and see when it locks-up as well.
The stock replacement converter the GM dealer put in mine lasted until it was out of warranty...LOL
The only REAL fix is an aftermarket converter with the billet front and multi-disk lock-up clutch. You'll have to have the TCM unlocked so you can change the trans lock-up characteristics, line pressure, torque management, etc.
Best of luck to ya. Maybe you'll have better results than I did.
Thanks
I'm surprised that anticipating several transmission fluid drainings & refillings that there isn't a DRAIN PLUG "kit" to be installed ... ?
COOP
...
Isn’t the fluid capacity on those transmissions like 14 or 15 quarts? If so that’s a lot of ATF to flush one out
Glad we know if it fixed it because the 890 bucks i spent flushing my 2020 made it worse.
Rich if you don't mind me asking what is the adjustable torque impact are you using thank you
I have often heard that flushing and replacing transmission fluid on high milage transmission. Day around 100,000 miles can cause problems. I have been working on cars as a hobby since the mid 1960's and am wondering if there is any truth to this. My present faily driver has just reached 100,000 and the dealer is calling for this service to be done. I've come to trust your judgement. Thanks
Not really. Most folks change their fluid after they notice the fluid looks really bad, or when experiencing other issues. At that point, the transmission is on borrowed time. But, they just replaced the fluid 5000 miles ago, so the fault was changing the fluid, not their own negligence.
That's like saying putting fresh gas in your car will ruin the engine. Makes no sense to me.
Only drain n fill especially on gm cars
For GM- I think it’s best to do a fluid exchange, not a flush.
I know on the sixth and eight speeds, rebuilders are using the mobile 1 synthetic LV ATF HP “blue label”.
Getting the 2015 3500HD done now, bad bearing in the transfer case. Full of metal. New transfer cases a coming
Did that take care of the problem. Ive got a 2017 and mine shudders sometimes and only at very low rpm while slowly accelerating in 5th or 6th gear
Our customer has been happy with it so far. Hopefully he was lucky and it holds the test of time.
Interesting content thanks
Thanks for the information.
Actually struggling with this problem with a 2018 Chevy Impala currently ugh
I am in Springfield ohio.
Any shops that you recommend in the area?
Impala owner here....add 1 or 2 tubes of shudder fix to your existing trans fluid and it should stop shuddering almost immediately or within 20mi max
@@midwesthustla02i did a drain n fill on my 16 ltz n added one tube of lubegard my shit still shuddering i did the drain n full 3 days ago i see u say one or two tubes…. Im thinkin add another tube??
@OGkevo1231 i had to add 3 tubes and now it only shudders uphill in overdrive....it was way worse before....I'll drive it for some miles and then change the fluid and filter again and add 2 more tubes....the problem is that we need to keep changing the fluid and add more tubes until the torque converter fluid is clean
@@OldCelticWarrior triple edge performance is in Ohio
I wouldnt flush the trans
if thats an 8 spd trans the flush will not fix it for a long period of time ,, sorry , that trans has a known shudder problem right from the factory , gm says its a failing torque converter , replace converter and its all good !!!?? until its out of warranty , then it needs a trans. well thats gms fix to get it out of warranty . that truck is probably gonna need a trans , with new cooler a new valve thats on the trans lines and a program !!! good luck maybe that flush will fix it long enough for the customer to drive it to a dealer and trade it in !!
GM trans tech here, the last iteration of fluid and the flush procedure has cured damn near every shudder I have had in an 8 spd. My wife’s car has 145k on it and hasn’t shuddered since the last design fluid was used over 100k miles ago. I have changed the fluid every 50k since and did a filter at 100k and have never seen another shudder. At some point converters might fail, but the last design Mobil 1 hp atf fix’s the shudder in most.
@@dickbrugh5562 yes if a trans is serviced on a regular basis and a full sythetic atf is used yes it will prolong its life without a doubt and help . But !!! Gm had i big problen with the 8 spd trans , its no secret , no mystery at all , almost all of them no matter the mileage have had a shudder issue /complaint and the fix per gm is flush trans and replace converter , but with that in mind , if a converter comes apart just replacing it and flushing is not going to fix the problem in the long term , metal has been sent through the trans and the pump , also why are they shuddering ??? Well programming , lack of maint, and overheating fluid , due to the thermal valve on the trans lines at the trans , required replacement with a reman unit ,huh why ??? They fail ! And starve the trans for fluid . I worked for a gm dealer as a tech for a short time , and seen trucks with low miles and high miles have trans issues with the 8spd , i also work for a trans shop for a long time and we would replace the 8spd gm trans constantly, until .. they went on national back order , why ? High failure rate at all mileage intervals . In short .. the gm 8spd in oem form is junk , an aftermarket reman unit from jasper is superior , and the problems fixed as long as the install instructions are followed ,correctly .
I like to repair vehicles so the repair lasts , not band aided , a flush on a high mile trans with shifting / shuddering issues is just that a bandaid . Just enough to trade it in and walk away .
@@jeremyalbert2069 Did I mention I was a GM transmission tech for the last 15 yrs? Not trying to be an ass, but you’re not telling me anything I don’t already know. I build my own performance units for myself and friends on the side. About to build my buddies 6l80e after it shit the converter. Well versed in GM transmissions.
@@dickbrugh5562 Any suggestions on finding a local Transmission guy who knows 8L90s? The couple of independent shops I have been to have no experience with the 8-speed. Prefer to avoid the dealer, who's suggestion for pretty much every issue is to replace it (transmission, engine, etc).
Do they ever make it easy? Engineering doesn't care about maintenance or r&r.
Unfortunately the days of wrenchers building things are done, everything is engineered and usually not by folks with dirty fingers!
these new vehicles are nothing but OVER PRICED GARBAGE