Transmission shudder

redneckmoose · August 16, 2022

My truck shudders at low speeds, generally city speeds from 30/35 to around 50/55 MPH. It is not a constant shudder and usually occurs while cruising, not accelerating. It will stop if I ease of the pedal or speed up a tid bit. Most often than not, it will happen in the 30/35 to 40/45 MPH range. I cannot ever tell, but to me, it seems like it happens when it is between shifting or something? A mechanic friend suggested it may have something to do with the torque converter? Although I can pull 'em and put 'em back in. I am not much more than a DIY shadetree mechanic that works on my own. This is irritating as hell.

rav3 · August 16, 2022

7 minutes ago, redneckmoose said:

My truck shudders at low speeds, generally city speeds from 30/35 to around 50/55 MPH. It is not a constant shudder and usually occurs while cruising, not accelerating. It will stop if I ease of the pedal or speed up a tid bit. Most often than not, it will happen in the 30/35 to 40/45 MPH range. I cannot ever tell, but to me, it seems like it happens when it is between shifting or something? A mechanic friend suggested it may have something to do with the torque converter? Although I can pull 'em and put 'em back in. I am not much more than a DIY shadetree mechanic that works on my own. This is irritating as hell.

How many miles? And what transmission? 6 speed or 8 speed

TheDave29 · August 17, 2022

I have the same problem, I bet if you watch your DIC you will find it happens at those speeds when you are in V4 mode. Will happen in V4 mode at those speeds usually around a slight incline. Press the gas pedal a little more and it goes into V8 mode and disappears. This happened really bad while towing my camper and lead to a transmission replacement at 98,000 miles (most likely not the problem). 2 years later this seems to have come back with the symptoms you described. Right now it is more of a buzzing then a shudder but when it was shuddering was when I was pulling my camper.

Carpenter Mike · August 18, 2022

My 2017 Sierra Denali is also doing the same thing, usually notice it after going around a corner just after I lift my foot off the brake and start slowly accelerating. Perhaps it's going into second gear without enough fluid pressure to complete the shift in short order. At first when it started doing this, I though there was some "washboard" in the roadway, but it seems to be happening in every corner. I have 26,000 miles but the warranty is long gone. I'm thinking about selling it before it breaks and leaves me with a big bill....

Carpenter Mike · August 18, 2022

As far as the motor being in 4 cylinder mode, the only time mine is in 4cyl. is when I'm coasting down a hill. The 4cyl. mode doesn't have enough power to get out of it's own way, total joke....

JimCost2014 · August 18, 2022

1 hour ago, Carpenter Mike said:

My 2017 Sierra Denali is also doing the same thing, usually notice it after going around a corner just after I lift my foot off the brake and start slowly accelerating. Perhaps it's going into second gear without enough fluid pressure to complete the shift in short order. At first when it started doing this, I though there was some "washboard" in the roadway, but it seems to be happening in every corner. I have 26,000 miles but the warranty is long gone. I'm thinking about selling it before it breaks and leaves me with a big bill....

Check with your dealer to see if you can still have the TSB done switching to the Mobil 1 Blue Label fluid.

Does not hurt to check, would save you money, it did work on my truck to get rid of the shudder.

Abdulla Muhsen · August 19, 2022

Dear All,

I have Denali 2014 pickup and facing the same issue in the transmission between 1500 -2000 rpm. anyone resolved this issue and can share his experience please?

I took my car to GMC dealer and waiting for their investigation result and will update their observations.

Regards,

Abdulla

JimCost2014 · August 19, 2022

11 hours ago, Abdulla Muhsen said:

Dear All,

I have Denali 2014 pickup and facing the same issue in the transmission between 1500 -2000 rpm. anyone resolved this issue and can share his experience please?

I took my car to GMC dealer and waiting for their investigation result and will update their observations.

Regards,

Abdulla

6 Speed?

If so, probally your torque converter is going to need to be replaced.

Abdulla Muhsen · August 22, 2022

Thank you JimCost2014 for your advise. will replace the torque converter and update.

Regards,

Edited August 22, 2022 by Abdulla Muhsen

Abdulla Muhsen · August 22, 2022

yes its 6 speed

elcamino · August 22, 2022

Seems owners are obsessed with motor oil changes every 3,000 miles but when it comes to the transmission fluid, it's OK to ignore it.

The oem's like GM spec out fluids but they get supplied by the lowest bidders that just meet spec. Like almost everything manufactured by low bidder, they use the cheapest (and often lowest priced) additives to meet the low bid.

Example.....this pertains to GM 8-sp transmissions

GM Dexron HP

"The base stock of old fluid (19355656) has the ability to attract low levels of moisture, which can cause degradation of the coefficient of friction of the fluid. The new fluid (19417577) has a new GTL (Gas to Liquid) base stock that is able to tolerate more moisture. Shuddering transmissions and torque converters have been recovered with the new fluid. New transmission fluid tests have been developed due this issue to prevent it from occurring with new transmission fluids."

NOTE-GTL fluid is an improvement over the existing fluid but GTL base stock is still a compromise over using a better PAO base stock which is more expensive.

Edited August 22, 2022 by elcamino

Abdulla Muhsen · August 23, 2022

23 hours ago, Abdulla Muhsen said:

Thank you JimCost2014 for your advise. will replace the torque converter and update.

Regards,

Hi,

I replaced TC and the problem resolved completely. The shuddering sound gone and shifting between speeds became more smooth.

Thanks JimCost2014 again for your advise and information.

Regards,

Edited August 23, 2022 by Abdulla Muhsen
correction

pokismoki · August 23, 2022

change fluid, then do a [trans reset] at the dealer. use 5th gear to keep it out of v4

Edited August 23, 2022 by pokismoki

virtuallyunlimited · September 2, 2022

Same issue here, 2014 Sierra, around 98K miles. To prevent it I can either put it in 5th gear, or put it in tow mode.

Eddie 70 · September 5, 2022

I have posted a similar answer to this type of thread before. On my 2014, I initially changed the fluid around 65k miles along with the filter. The fluid looked like chocolate. I have since changed 1 gallon of fluid every 15k miles. I use a hand pump and pull the one gallon of fluid out of the dipstick and replace it with a fresh gallon of fluid. I am at 118k miles. The fluid looks brand new now. I don't know whether this will allow my transmission to live longer or not, but for the price of one gallon fluid, it's a no brainer. It takes me 20 minutes to the the job and I feel like I have done something good for my transmission.