Transmission Flare

[Shel_B]

What causes transmission flare? How bad is flare for the life of the unit? Is it worse than or about the same as slipping? Thanks!

Just to be clear, I don't have the problem but, about a year ago, I experienced three instances of flare on the 2-3 shift after a complete change of fluid. The flare disappeared before I could get the car to the shop, and it never reappeared.

 

[oldhp]

Probably had some air in the valve bank spools. After a couple cycles it bled out. You should be ok now.

 

[The Critic]

Just to be clear, I don't have the problem but, about a year ago, I experienced three instances of flare on the 2-3 shift after a complete change of fluid. The flare disappeared before I could get the car to the shop, and it never reappeared.

I have seen this issue due to low fluid level, especially when the transmission is cold. The temp range for setting the fluid level can be difficult to achieve for a busy shop, so a lot of people do it when the transmission is still to warm and this results in a low fluid level when cold.

 

[Shel_B]

I have seen this issue due to low fluid level, especially when the transmission is cold. The temp range for setting the fluid level can be difficult to achieve for a busy shop, so a lot of people do it when the transmission is still to warm and this results in a low fluid level when cold.

That's good to know. However, I don't think that's the situation in this instance as the shop had the car overnight, and was able to work on the car when it was cold.

 

[CKN]

Some transmissions will flare at times. The 6 speed in the Silverado is one that does. It's a feature of a $50,00.00 truck-included at no additional charge....

 

[Hyundai Respecter]

My old Elantra 4sp automatic would have a 1-2 flare and sometimes 2-3 depending on what speed I was going. Usually would notice it when driving/accelerating slower, like in traffic.

It didn’t seem to hurt anything, the car is with another owner now but still running fine and has over 160k or so on the original transmission.

I noticed on rock auto a company called TransGo that sells a shift improvement valve kit for it that is supposed to fix the issue. Maybe they have something similar for yours too

 

[charbaby]

I experienced shift flare on a 2004 Altima 2.5S. It would only happen on the 1-2(always) & 2-3(often) when cold from about year 8.
As long as I drove the car easily til she warmed up, it WOULD NOT happen throughout the day even at WOT.
However, if I drove the car(cold) just a bit more aggressively, she'd do this causing me to back off. I changed the ATF regularly from new and drove the car for 12 yrs without further issues. Even drove down the east coast from NY to FL often.

My first ATF change from OE(MeticD) was with Mobil 1 ATF and all was well. My 2nd ATF change was with Valvoline Castrol IMV. Soon after is when this started to happen. My 3rd change was with Valvoline MaxLife and it got just a tiny bit better. I don't blame the Castrol IMV as this SHIFT FLARE turned out to be common on Nissan forums.

 

[Lubener]

What causes transmission flare? How bad is flare for the life of the unit? Is it worse than or about the same as slipping? Thanks!

Just to be clear, I don't have the problem but, about a year ago, I experienced three instances of flare on the 2-3 shift after a complete change of fluid. The flare disappeared before I could get the car to the shop, and it never reappeared.

Older hydraulic or newer computer controlled? Without knowing what transmission your talking about, this is just guesswork. It is not normal and any slippage over time can be damaging.

 

[Shel_B]

Older hydraulic or newer computer controlled? Without knowing what transmission your talking about, this is just guesswork. It is not normal and any slippage over time can be damaging.

The car is in my sig: 2011 Camry

 

[Shel_B]

Older hydraulic or newer computer controlled? Without knowing what transmission your talking about, this is just guesswork. It is not normal and any slippage over time can be damaging.

The car is in my sig: 2011 Camry

 

[64bawagon]

My 2021 Silverado does this on the 6th to 5th downshift. Surprisingly enough..... no one can say why. I have only seen it when towing so I run a little slower to avoid it going into 6th, it stays in 5th and the issue is avoided.

 

[CKN]

Older hydraulic or newer computer controlled? Without knowing what transmission your talking about, this is just guesswork. It is not normal and any slippage over time can be damaging.

No-some transmissions flare. You can spend plenty of time over on the GM trucks boards and read about flare. With computer controlled transmissions- "Flare" and "slippage" are two different things.

 

[clinebarger]

While ATF should retain it's frictional characteristics/behavior throughout its life....That's not always the case. New fluid....Especially in the case of total exchange can change the frictional behavior just enough to cause shift issues 'til the Adaptive's update/learn.

But, Don't dismiss what Critic posted as it's very common for a shop to leave a unit under filled!

 

[nicholas]

What causes transmission flare? How bad is flare for the life of the unit? Is it worse than or about the same as slipping? Thanks!

Just to be clear, I don't have the problem but, about a year ago, I experienced three instances of flare on the 2-3 shift after a complete change of fluid. The flare disappeared before I could get the car to the shop, and it never reappeared.

Lubegard helped in a caravan we had last year.
2-3 shift

 

[Propflux01]

Lubegard is about the only Transmission supplement that actually works.

 

[Shel_B]

While ATF should retain it's frictional characteristics/behavior throughout its life....That's not always the case. New fluid....Especially in the case of total exchange can change the frictional behavior just enough to cause shift issues 'til the Adaptive's update/learn.

But, Don't dismiss what Critic posted as it's very common for a shop to leave a unit under filled!

Thanks for the info about frictional behavior. Since the problem only happened a few times soon after the fluid was changed, it may be possible that that was the cause.

I'm not dismissing what Critic said, I'm just uncertain that underfill was the cause. If the unit was underfilled, and the underfill was causing the flare, wouldn't the transmission continue flaring until the fill level was corrected?

 

[clinebarger]

Thanks for the info about frictional behavior. Since the problem only happened a few times soon after the fluid was changed, it may be possible that that was the cause.

I'm not dismissing what Critic said, I'm just uncertain that underfill was the cause. If the unit was underfilled, and the underfill was causing the flare, wouldn't the transmission continue flaring until the fill level was corrected?

An underfilled condition can be masked by higher ambient temperatures, then symptoms reappear at colder temperatures....Just something to be mindful of.

 

[nascarnation]

Adaptive control (at least the one that I'm familiar with) is programmed to apply the minimum hydraulic pressure to achieve the prescribed time of slippage to make the shift. So it "wants" to be right on the edge of flare without allowing it consistently. It may back off pressures gradually until it sees a small flare (ex 100 rpm), then adapt up on the next shift of that type.

 

[Shel_B]

An underfilled condition can be masked by higher ambient temperatures, then symptoms reappear at colder temperatures....Just something to be mindful of.

Good point. Didn't observe any flare this past winter when it was the coldest it had been since the fluid was changed last February 25th.

Since I'm not observing any flare, and haven't for a while, do you think it's worthwhile to have the level checked just to be sure, or perhaps just not do anything until or if it happens again?

 

[Accent Abuser]

My 2021 Silverado does this on the 6th to 5th downshift. Surprisingly enough..... no one can say why. I have only seen it when towing so I run a little slower to avoid it going into 6th, it stays in 5th and the issue is avoided.

Probably getting the fluid too hot and thinning it out, you should probably manually shift when towing and stay out of top gears and especially overdrive.