Transmission issue only when cold

[Steven Muraoka]

My problem happens after my truck (2017 5.3/6sp DC) has been sitting overnight or longer than 8 hours. 

After I start the truck and drive, the 3rd to 4th gear shift will hesititate and buck a little at low to part throttle. If I add throttle, the issue will smooth out somewhat.

This will generally occur once, and for the rest of the drive the truck will perform normally. The RPMs do not seems to be affected while this is happening.

I took it to the dealer who could not reproduce the problem. They checked the transmission fluid level and said it was normal.

This issue only occurs during the first drive and is not present at any other time.

Would changing the transmission fluid/filter help any? The truck has 15K miles.

Thanks for any advice.

 

[Steven Muraoka]

3 hours ago, mjm-1957 said:

When the truck sits overnight the clutch hydraulic circuits drain out and fill with air.The first shifts in the morning are actually purging the air from the hydraulic circuits causing some weird and erratic shifts. I am the transmission guy at a Buick- GMC dealer and also own a 2017 6.0 2500 hd with a 6l90e in it, it also does the same thing once the first time i drive it, normal. Won't hurt anything. GM has a TSB about the same thing.

I have read about this somewhere on this site. I believe the TSB you mentioned was also posted there as well. If memory serves right, the TSB stated that no attempt to repair this condition should be made, as it is "normal".

Although fairly minor in nature, this issue is annoying for a truck with only 15K on the clock. It has done this since new.

As diyer2 mentioned earlier, would a tranmission fluid/filter change have any affect on this issue? Maybe an aftermarket fluid other than the factory fill?

Thanks for all the replies so far!

[Jsdirt]

A testament to GM's shoddy, corner-cutting engineering. You'd think for $50 LARGE you'd get a vehicle that performs to your expectations.

 

Our grandfather's generation would've never put up with this - why do we??

 

Yet another reason to keep fixing my relics ...

 

Just FYI - there are THIRTY SIX TSB's for this transmission!  I assume you have a 1500? Do you know which trans it has?

[diyer2]

How about this.

 

 

I have one of these. Works great.

Suck out transmission fluid and refill.

Maybe use a quality trans fluid, Amsol?

I use it for transmission fluid, coolant fluid, power steering fluid.

Link for purchase https://www.amazon.com/gp/product/B0002AJR8E/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

I do a full service of these fluids then refresh the fluids with this.

Transmission, drop pan, new filter around 60 K miles. Every 10 K miles because I tow in the mountains of Colorado I suck out I believe it's 5 or 6  quarts and refill.

 

[KARNUT]

My grandmother, my mothers mom, had 2 cars I can remember. A 55 Chevy, 65 chevy biscane. My wife took her driving test in it in 1974. My barracuda was a stick. It still was going years later. Oil change and wash once a year. She wasn't afraid to drive. No power steering, brakes. She had school buses drove them too.


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[Jsdirt]

If it's out of warranty, bring it to a transmission specialist that will get paid to diagnose the problem.

 

If still under warranty, keep bringing it back until it's FIXED. When you get tired of that, call corporate and complain.

[Doug_Scott]

I would suggest you park your truck at the dealership one night and the next day you show up bright and early and take the transmission mechanic and service manager for a drive.  You drive first, no matter what they want.  You know how to create the issue, they don't.  That being said, sometimes once you know how to get it to do something odd, your driving habit will change to make it do it every time, yet nobody else could ever get it to do it. 

[mjm-1957]

When the truck sits overnight the clutch hydraulic circuits drain out and fill with air.The first shifts in the morning are actually purging the air from the hydraulic circuits causing some weird and erratic shifts. I am the transmission guy at a Buick- GMC dealer and also own a 2017 6.0 2500 hd with a 6l90e in it, it also does the same thing once the first time i drive it, normal. Won't hurt anything. GM has a TSB about the same thing.

[Doug_Scott]

On 2/1/2019 at 10:41 AM, Jsdirt said:

A testament to GM's shoddy, corner-cutting engineering. You'd think for $50 LARGE you'd get a vehicle that performs to your expectations.

 

Our grandfather's generation would've never put up with this - why do we??

 

Yet another reason to keep fixing my relics ...

 

Just FYI - there are THIRTY SIX TSB's for this transmission!  I assume you have a 1500? Do you know which trans it has?

My grandfather used to replace his vehicles at 20,000 miles. His reasoning was they just start costing too much to keep them in good enough condition to be reliable for his yearly run from Gananoque to st Pete's in Florida.  I can remember going to stay at his house on the st Lawrence River wondering if itt was new car year.  I don't know how he did it, he owned his own shoe repair business. 

[Jsdirt]

My grandparents and parents used to sell their cars at 6-8 years, only because it was time to buy something shiny. Cars & trucks were always in top condition when sold, some well over 100k miles.

 

My dad towed a 21' Prowler camper with our '76 Torino for years. I can remember the catalytic converter getting so hot we couldn't touch the floor, even through the carpet. Could smell it melting to the floor. About the only problems with those cars were emissions after '72. That thing went all over the country towing that camper! Try that with a modern CAR, lol. That one had 130k or so when sold.

[diyer2]

 Try changing the fluid and the filter.

Won't hurt anything.

 

 

 

[BigBadSierra]

Cold fluids move slower. Increasing your speed forces the fluids through faster.

 

I assume the issue goes away once the transmission warms up.

 

My last truck sat in two feet of snow for four days it was real stiff when I started to drive it out of it's bush parking spot.