8l90 Shudder Out of Warranty DIY

[matt-tastic]

Hello all!  First post here!  What brought me here was the 8l90 torque converter lockup shudder issue.  Most times I'd just take this truck to the dealer and let them sort it out, but as it's out of warranty, this is not something I'd like to pay >$600 to repair (this price was quoted to me for the flush and filter change).  After talking to a few service advisors I've found that each of them planned on using a different solution to attempt to alleviate the shudder.  The first was going to proceed via one of the bulletins and do a triple fluid swap and filter change, the others were just going to do a standard flush and fluid swap.  I plan on owning this vehicle for another few months until the 19's become a little more negotiable but cannot stand to let this shudder go on that long and am a bit worried about destroying the torque converter in the process and washing a whole bunch of parts down into the transmission.  So.... my question is if anyone has performed this fluid swap themselves, if it alleviated the issue, and if the filter change is necessary?  I saw that many of the Corvette guys were swapping to the Mobil 1 fluid with some success, however, I didn't think this was as much of a fluid performance issue as it was a suspended clutch material / dirty fluid issue.  Any help would be greatly appreciated!!!!!!

[MY164X4]

Probably should flush your self .
I'm in the same boat.16 Sierra

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[TJay74]

There is more than just flushing the fluid, some years the TSB does require the transmission to be dropped and some clearances in the transmission front pump to be checked to make sure the pump wasnt damaged. My 2016 is going into the dealer in the coming weeks, dealer said they will need it for 1 week to pull the transmission. It will require a new torque converter, fluid, filter and possibly either rebuild the front pump or a new front pump if mine is out of tolerance.

[Snowmobile Mike]

On 9/21/2018 at 11:24 PM, TJay74 said:

There is more than just flushing the fluid, some years the TSB does require the transmission to be dropped and some clearances in the transmission front pump to be checked to make sure the pump wasnt damaged. My 2016 is going into the dealer in the coming weeks, dealer said they will need it for 1 week to pull the transmission. It will require a new torque converter, fluid, filter and possibly either rebuild the front pump or a new front pump if mine is out of tolerance.

Is your vehicle a 1500 Sierra ? How many miles on it ? Reason being  I have a 16 Double cab All Terrain and been having issues . I use truck for work and pulling 2000 lbs Snowmobiles and trailer in Winter and 2800 lb small boat in Summer , I only have 32,000 miles on it bought with 31,change it's still in Warranty ! It's at dealer now first they said they wont do flush then I called my Attorney and told them I want my money back they then said they would pay GM dealer to do it ( my dealer is a Dodge ( I bought used ) I'm inclined to just get my money back and get a different truck ! I can't be putting up with this crap ! Plus local dealers haven't even done a flush ! These dealers are a hour a way each way . Not a Happy camper here !