2015 Yukon Denali 2WD Excessive road vibration and transmission shudde

[robphelan]

6 hours ago, dwchapmanjr said:

Could be the TCC but the detect that plagued 2015i/2016 shouldn't have persisted into 2017.  It can also be the AFM.  When in manual mode the AFM is supposed to be disabled.  I've heard the fix for shuddering due to AFM may be a fuel injector cleaning and in some cases the shop will disable AFM if its really annoying/problematic.

 

After 3 years of the transmission though I will say that sometimes it just shifts roughly or clunks and ocassionally I'll still get a shudder when shifting even after the TCC was replaced.

I don't think it's AFM - maybe.. it happens very frequently.. even when accelerating from 0.. when all 8 cylinders should be  being used. at almost every shift I can feel it. although, i didn't feel it when the engine sat overnight.

[dwchapmanjr]

I haven't had to do a ton of highway driving since I had the TCC replaced but recently had to twice and noticed the terrible shudder.  Most of my driving has been back roads with a top speed of 45.  This time it seems a bit different though.  Previously I could notice it at any gear with light acceleration but now it only seems to happen in 8th with AFM on.  I could not reproduce in manual 7th but I do not do a ton of highway driving so I'll have to test further and likely have them check this out at my next oil change.  Unfortunately PIP-5337 states if it appears to be AFM related, this is normal.  Sometimes I can get it to shudder for quite a few seconds while its still in 4 cylinder though.

 

PIP5228 seems close but doesn't apply to V8 and it seems to imply a constant vibration.  This vibration happens when tapping gas pedal or touching it lightly when in the 1200-1600 RPM range only in 8th with AFM on.

[dwchapmanjr]

Just an FYI on this.  I scheduled a service appointment because I needed some fluid changes and to do the Electric Power Steering recall as well and mentioned the shudder.

 

I go in next Wednesday and sounds like they want to keep it for a few days but he did mention GM is having them put a new transmission fluid in this and its "supposed to" correct this but that they just started swapping these fluids out about 2-3 weeks ago so he couldn't say whether he's seen improvement.

 

When I originally had this issue the bulletin PIP5337 was up to E and there is now a PIP5337K which references bulletin 16-NA-175 which is just a double fluid flush.  I will post an update when I get it back but I imagine it will take a week or so for the transmission to learn again even after a fast learn.  My driving patterns don't usually allow me to reproduce this issue either.

[Tahoe02]

I was told by a friend, service writer, that GM was coming out with a new fluid after the first of the year to address this issue. good luck with the repair.

[dwchapmanjr]

9 hours ago, Tahoe02 said:

I was told by a friend, service writer, that GM was coming out with a new fluid after the first of the year to address this issue. good luck with the repair.

Yes, I've read a few forum posts and seen that the new fluid is hopeful to resolve this.  My dealer has been doing the new fluid for 2 weeks now.  Apparently the old fluids retain water over time which makes sense why it has taken so long for them to resolve this.  Fingers crossed!

[dwchapmanjr]

I just took my truck in and they flushed it with the new fluid.  The paperwork is pretty light on details but listed the new procedure 18-NA-355.  Runs perfectly, just as it did after the last fluid flush and TC replacement.  Fingers crossed this is it.

[dwchapmanjr]

I just realized I had not updated this post with the information on the new procedure.  There are a couple other forums that I was posting on.  The new procedure is 18-NA-355 which includes a new tool used to flush/fill and a new fluid.  Its the new fluid that is supposed to be a permanent fix.  Part number on the fluid is 19417577.

 

After a day driving in various conditions the transmissions is still very responsive.  This is supposed to be the final fix but only time will tell as this issue does not immediately reappear.

[daxden]

On 8/31/2016 at 6:12 PM, dwchapmanjr said:

 

Yes, TCC = Torque Converter Clutch

 

I found that if I warmed up the transmission by driving on the highway I could easily reproduce it constantly at 70mph or at lower speeds after TCC fully locked and slightly pushing the gas.

 

The dealers do not like being told how to diagnose the problem but make sure they are aware of PIP5337 (specifically PIP5337 revision E From Aug 2016) for the TCC issue. If they have not done many TCC replacements they may not be aware of it.

 

There is a separate bulletin for the lurching from park to drive. The stator needs to be reinserted and I would make them aware of both of these issues and service bulletins beforehand as they might as well address the stator while replacing the TCC.

 

They may run the calibration if you have never had it done or are not running the latest for the TCC. It will run rough for a few tanks of gas afterwards but if you're feeling the issue now, it ultimately won't resolve it because the TCC is probably heavily worn already which that calibration is supposed to help avoid.

I have a 2016 Suburban LT.  I own a transportation company and generally put between 50-70k miles per year on our SUVs. 80% of them are having transmission issues around 160k miles. I started having issues with it slipping and hard shifting at about 100k miles. I also had the shuddering/vibration issues. So, I opted to have a new/rebuilt 6-speed transmission installed 3,000 miles ago. What didn't change was the shuddering/vibration. It's more noticeable around 1200 rpms. It's weird because if I am on the accelerator it vibrates. As soon as I let off, it just about goes away. I took it back to the GM dealership, and of course they said some BS that the vibration was normal - the Service Manager actually did a ride-along and noticed it as I was driving. He said it was the TCC. They reprogrammed the Transmission, as I was and still having issues with the Active Grade Braking not engaging correctly after the new transmission.