Transmission flush at 107K, transmission shudder at 111K…‍♂️‍♂️‍♂️

[Bigell]

Folks. On my 2020 Yukon I did the “recommended” maintenance and changed the tranny fluid at over 107K miles. Now at 111K I’m getting that damn tranny shudder, rpm’s up and down, and hard shifting. Mechanic said it was a bad idea to change the fluid. Any insight???

 

[pronstar]

The recommended transmission maintenance schedule is every 100k miles?

I’d be on my third trans service at 100k…

If this was the first service then yes, you’re rolling the dice.

 

[the 18th letter]

Yup GM recommends it at 100k and I’ve found several GM dealers who will tell you they won’t touch it at that mileage. People will also tell you it’s ancient thinking being worried that changing the fluid will cause issues. Was it a flush or just a change of fluid? The flushes seem to be what you should avoid on higher mileage vehicles.

 

[West 1]

I agree, avoid the flush route. stirs up too much junk from the dirty tranny pan into your Techm body and all the valves and solenoids that control your tranny. I would not hesitate to change the fluid IF, you drop the pan, clean it and install a new trans filter with the fluid change. Understand that this will only change the fluid in the tranny pan and will not change what is inside the torque converter. So you will get about 5 new quarts inside with a pan drop and fluid drain.

Changing your fluid in the pan more frequently keeps cleaner fluid in the system and will extend your tranny life.

Some will install a new tranny pan that has a drain built in so you can do another fluid change after driving a. little with a lot less effort. Otherwise it would be good to drain a second time after driving the truck a couple hundred miles to pump newer fluid into your torque converter. A new filter should be installed maybe every 60,000 miles? Factory says 100K. What you choose is up to you.

As far as your situation, just changed the fluid and now have a shudder. Sounds like the system might just be low on fluid? Pan leak or under filled? First thing to check and maybe you already have?

 

[randeez]

Folks. On my 2020 Yukon I did the “recommended” maintenance and changed the tranny fluid at over 107K miles. Now at 111K I’m getting that damn tranny shudder, rpm’s up and down, and hard shifting. Mechanic said it was a bad idea to change the fluid. Any insight???

What trans- 8 or 10sp?
What fluid did you use
Did you check level correctly?

 

[West 1]

This is a new Tranny pan with a drain plug for the 6L80 for example: https://www.amazon.com/Transmission...T1zcF9hdGY&psc=1#averageCustomerReviewsAnchor

 

[Bigell]

What trans- 8 or 10sp?
What fluid did you use
Did you check level correctly?

8 Speed…No idea what fluid was used but the

Yup GM recommends it at 100k and I’ve found several GM dealers who will tell you they won’t touch it at that mileage. People will also tell you it’s ancient thinking being worried that changing the fluid will cause issues. Was it a flush or just a change of fluid? The flushes seem to be what you should avoid on higher mileage vehicles.

it was a flush- “Transmission flush and fill kit-Remove all contaminated fluid refill with proper type and amount of new fluid-$225

 

[West 1]

With most flushes they remove one tranny cooler line and tap into the system. New fluid is pumped in as old fluid is pumped out. They do this normally until clean fluid is being pumped out. The pan is not dropped and no new filter is installed so you still have a dirty 109,000 mile filter in there. The flush also stirs up the dirt in the bottom of the tranny oil pan and can move it to places that cause damage.

I am sensitive to this because I had my 2001 GMC Denali with a 4L65E tranny flushed around 55,000 miles, tranny failed at 59,000 miles. Before my Denali tranny failed I decided to flush our 95 Suburban that was almost at 150,000 miles. Denali tranny failed right after that and while I had it in the garage installing the new tranny the Suburban 4L60 failed so I had two broken transmissions at the very same time.

My friend who owns a very good tranny rebuild shop did both transmission repairs for me. Told me the junk in the pan on both tranny's had plugged up the transmission and caused failure. He barked at me to never do a flush, just do the pan drop and new filter install.

I believe him now and I paid twice already for doing flushes. That was enough. The Denali tranny was flushed in Texas, I was on a trip and stopped for an oil change, they sold me on a tranny flush. My mistake, glad it at least made it back to California before it broke. The Suburban tranny was flushed in Sacramento. Had the same result. So two shops did my flushes with the very same results.

I am sure the shops have done thousands of flushes with zero problems but I went 2 for 2.

 

[randeez]

8 Speed…No idea what fluid was used but the

it was a flush- “Transmission flush and fill kit-Remove all contaminated fluid refill with proper type and amount of new fluid-$225

if the trans(converter) is shuddering its likely already cooked.
ive been thru it with the 8sp, many flushes, couple converter changes, dealer finally got it right but it was at their expense

if it was on my on dime i would probably try a pan drop to replace the filter, get as much fluid out as you can. GM now recommends mobil blue label LV fluid in the 8L90. possibility its already gone and youve just wasted 200bux on fluid/filter (assuming DIY). but for me it would be worth a shot before dropping trans and replacing converter

 

[ReaperHWK]

I got rid of my 2015 after the torque converter was shuddering bad. Had 170k miles.

Not a fan of these trannies!

 

[randeez]

i swapped a 10l90 in mine,
8sp was actually working pretty good when i did though

 

[Bigell]

if the trans(converter) is shuddering its likely already cooked.
ive been thru it with the 8sp, many flushes, couple converter changes, dealer finally got it right but it was at their expense

if it was on my on dime i would probably try a pan drop to replace the filter, get as much fluid out as you can. GM now recommends mobil blue label LV fluid in the 8L90. possibility its already gone and youve just wasted 200bux on fluid/filter (assuming DIY). but for me it would be worth a shot before dropping trans and replacing converter

Yeah…I took it back to the shop that did the flush. Mechanic just looked at me like “okaaaay, so when can u bring it in so we can take a look, sounds like a blown transmission”. My other mechanic told me to bring it to him and he’ll try an anti-shudder fluid. He also said worst thing I could have done is flush the fluid. For what it’s worth I only did the transmission service because I didn’t want hear shit from Endurance Warranty (again) about an internally lubricated part not covered because the fluid wasn’t changed.

 

[Blackcar]

Well, you did what they wanted now Endurance can fix it.

 

[Bigell]

Well, you did what they wanted now Endurance can fix it.

Yeah, we’ll see if they do the right thing…

 

[gat0r]

known issue w/ 8 spd

i have a '15 & follow the Severe Maint schedule.... i change fluid & filter every 45k
not a single issue. 3rd chg was done last year

 

[PA-WOODCHUCK]

Purchased 2016 from dealer at 50K and they did the TSB. At 95K shutter started again and had shop change along with filter, flushed lines to cooler, Used current GM recommended fluid and FORD friction additive. Now at 118K and NO issues!

 

[Z15]

I found that most mechanics will simply use the cheapest parts/lubricants available. They say change the oil but ignore the transmission fluid. I bet the shop used some cheap generic ATF and these 8 and 10 speeds require a premium ATF like Mobil 1. Not the cheap generic crap most shops sell. Chance are its the cheap fluid that was used, there is a big difference in cheap vs. quality.

 

[Sundancer]

I agree, avoid the flush route. stirs up too much junk from the dirty tranny pan into your Techm body and all the valves and solenoids that control your tranny. I would not hesitate to change the fluid IF, you drop the pan, clean it and install a new trans filter with the fluid change. Understand that this will only change the fluid in the tranny pan and will not change what is inside the torque converter. So you will get about 5 new quarts inside with a pan drop and fluid drain.

Changing your fluid in the pan more frequently keeps cleaner fluid in the system and will extend your tranny life.

Some will install a new tranny pan that has a drain built in so you can do another fluid change after driving a. little with a lot less effort. Otherwise it would be good to drain a second time after driving the truck a couple hundred miles to pump newer fluid into your torque converter. A new filter should be installed maybe every 60,000 miles? Factory says 100K. What you choose is up to you.

As far as your situation, just changed the fluid and now have a shudder. Sounds like the system might just be low on fluid? Pan leak or under filled? First thing to check and maybe you already have?

This scares the crap out of me. My 2020 Tahoe RST just hit 60,000 miles and i am torn on if I should have this done at the dealer or my local mechanic or just skip it as I have no issues at all.

 

[West 1]

Change the fluid, traditional way, drop the pan, new filter and fluid. Good to go. No issues if you get the fill correct after the job. Measure what comes out and replace that amount if in doubt. Trannys run on fluid. the fluid needs to be clean.

 

[Bigell]

Yeah, tomorrow I’ll go back to the shop and ask them what they actually did (flush or drop pan, change filter etc) What fluid they used, etc. I drove it yesterday and it smelled like something burning. I was in reverse and barely made it out of the driveway. Crazy