2017 Yukon Denali Shudder Problem

[cirrusaviator]

Hey there,

I picked up a 2017 Yukon Denali with 60k miles on it from Carmax two days ago. I didn’t notice it during the test drive, but I’m experiencing a shudder that feels like driving over rumble strips.

I went back to Carmax yesterday morning, and they knew exactly what I was talking about. They said they would send it to GMC to perform a transmission fluid flush. If that resolves the issue, I should be good. If not, they would replace the torque converter.

My question is: if the flush is successful, should I expect the car to run fine for a while, or is this issue likely to reoccur after a few thousand miles?

We love the car otherwise, but we’re concerned.

Is there anything else with this model I should be thinking about?

Thank you!

 

[B-train]

I have the exact same vehicle. I bought it with 41k and had the shudder at 43k. The fluid flush works magic. I now have 162k on it and it's been great. Make sure to keep the fluid changed every 40k. I usually change the filter every 80k.

The fact that they offered to replace the TC is huge. Just keep good records. If you can get a flush out of it and a new TC, you'll be good for MANY miles.

My only concern from the whole deal would be HOW long has it been doing this with 60k on the clock. The fluid basically causes the TC to experience sticky spots due to the moisture that's trapped in the fluid - hence what you feel.

 

[cirrusaviator]

I have the exact same vehicle. I bought it with 41k and had the shudder at 43k. The fluid flush works magic. I now have 162k on it and it's been great. Make sure to keep the fluid changed every 40k. I usually change the filter every 80k.

Thank you! That's encouraging to hear.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

 

[cirrusaviator]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

Thank you! I will for sure be active in the forums. Our first GMC vehicle. I'll have to take more pictures from different angles soon.

 

[B-train]

Thank you! I will for sure be active in the forums. Our first GMC vehicle. I'll have to take more pictures from different angles soon.

I like that color and wheel combo. Mine is white tri-coat with the double spoke 22 inch wheels. They are nice rigs. I've (mostly my wife) has enjoyed ours for 120+k. Good power, good mpg, and nice creature comforts. I hope you have many miles of good use!

 

[kk1lron]

Along this thread I have seen mixed advice for this issue. One is flush the fluid and life is good. Other is time for a torque converter. I am kind of a fan of try the less expensive way first.

2015 Yukon XL here.

I have also experienced a occasional shudder which started happening around 112k miles. It had been quite subtle and maybe once to a few times in a 10 mile drive 30MPH to 60MPH (around town and bi-ways). Then last week the truck acted like it was in neutral except Park which worked. After the truck sat for several minutes I started it again and was able to drive (in the driveway), but not for long before when coming out of park it was neutral in any position. It did go into gear after sitting again and I parked it waiting for a tow to my mechanic.

When the tow truck arrived to take the truck I started it and there was a bit of a whiny noise from underneath the truck (it had not been run for a week) which lasted 10 seconds or so, then normal (this sound was not the short whistle-skreetch right at start which is pretty common). I was able to drive the truck onto the bed of "tow" vehicle.

Does this sound like a flush to fix, or a new TC situation? Any hints I should give the mechanic? It is on his schedule for Thursday.

THANKS!

Y'all like pics, so here ya go.

 

[B-train]

Along this thread I have seen mixed advice for this issue. One is flush the fluid and life is good. Other is time for a torque converter. I am kind of a fan of try the less expensive way first.

2015 Yukon XL here.

I have also experienced a occasional shudder which started happening around 112k miles. It had been quite subtle and maybe once to a few times in a 10 mile drive 30MPH to 60MPH (around town and bi-ways). Then last week the truck acted like it was in neutral except Park which worked. After the truck sat for several minutes I started it again and was able to drive (in the driveway), but not for long before when coming out of park it was neutral in any position. It did go into gear after sitting again and I parked it waiting for a tow to my mechanic.

When the tow truck arrived to take the truck I started it and there was a bit of a whiny noise from underneath the truck (it had not been run for a week) which lasted 10 seconds or so, then normal (this sound was not the short whistle-skreetch right at start which is pretty common). I was able to drive the truck onto the bed of "tow" vehicle.

Does this sound like a flush to fix, or a new TC situation? Any hints I should give the mechanic? It is on his schedule for Thursday.

THANKS!

Y'all like pics, so here ya go.
View attachment 442893

I'd check the fluid level. My wife explained a similar issue on our 8 speed with 162k. It ended up being a little low on fluid per my friend at the dealership. I ended up replacing the trans temp harness, filter, and fluid. Been fine since. Hoping for 200k out of it.

 

[kk1lron]

I'd check the fluid level. My wife explained a similar issue on our 8 speed with 162k. It ended up being a little low on fluid per my friend at the dealership. I ended up replacing the trans temp harness, filter, and fluid. Been fine since. Hoping for 200k out of it.

Thanks for that comment B-train. I had checked the fluid level (running cold) and was right in the hashes. The rig is in the hands of the shop today and we'll see what someone far more skilled than I finds.

 

[JMH1980]

Thanks for that comment B-train. I had checked the fluid level (running cold) and was right in the hashes. The rig is in the hands of the shop today and we'll see what someone far more skilled than I finds.

If you have a dipstick to check fl you I'd level, it's probably a 6L80 Transmission. The vehicle is going into a safety lock up because there are internal problems. I'm not an expert, but might be looking at a rebuild/replace situation, from what I've read on other threads.