Any one know what the main cause of a 'shift flare' would be?

I have a 2009 Escape with the "all new 6f35" six speed medium range transmission.

The original tranny was replaced after only 300 miles because of a 2-3, 4-5 and 5-6 shift flare problem.

The new tranny is a little better, but still has a sever 3-4 shift flare after vehicle has been driven and parked for 5 or more minutes. It also has a constant mild 4-5 shift flare once it is up to running temp.

Also, the replacement trany (brand new) blows transmission fluid out of the filler tube...the tech re-adjusted the fluid level a month ago, but it is still blowing fluid out of the filler tube.

The vehicle goes back to the Dealer next Thursday for more testing...

So my main question is, what are the usual causes of 'shift flare'?

 

Heat, leaking servo piston seals, leaking clutch apply piston seals, low apply pressure caused by restricted intake or ineffective pump, restrictions in the valve body or apply passages, misalignment of the 'stack' occluding apply holes, stackup of tolerances doing the same, both things restricting the volume and pressure of apply fluid.
What happens is that the trans tries to apply a clutch piston, or band servo, and it does not apply enough pressure or force to lock up the clutch or the drum, so it slips. When it slips, the engine races until it applies hard enough and quits slipping.
ANY slippage causes immediate heat buildup. Right now. Try holding an electric drill bit chuck with one hand, and turn it on with the other. Your hand will get hot instantly due to the friction. Multiply by rpms, torque and horsepower and you can see how it gets hot so quick.
You get fluid coming out the filler because 1)too much fluid or 2) too much heat. Either one, or both, cause expanded fluid volume - possibly due to foaming if the level is high enough to get into the rotating parts.
The fluid should be checked hot, and should not be above the hash marks on the dip stick. If you have a trans that has leaky seals(internal), you can get a lot of fluid blowing past the seals, causing havock spraying fluid around where it was not expected by the designer. That can lead to foaming and overflow.
Enough?

tom

 

tom, thank you for your reply.

You sound like know your transmissions!

I have been dealing with the Dealer transmission mechanic for over two months. Nice guy, seems sincere about fixing the problem I am having (installed new transmission, and spent an hour adjusting the fluid level after I realized it was blowing out of the filler tube)

The 'new tranny' shifts just like the origianal, only differance is the new replacement tranny blows fluid out of filler.

Is there any chance the PCM could cause the shift flare I am experiencing? It seems odd that a new tranny would do the same thing.

 

Yes.




ok, for more... The PCM could be sending the wrong signal or a 'wobbly' signal to the solenoids that open and close the valves that in turn direct the servos and pistons to apply and release. Or the pressure, which is also regulated by the PCM, could be inadequate. If the PCM is told that it is zero outside, it will then expect that the fluid is viscous, and apply the shifts in a different way. If the pressure sensor tells the PCM that the line pressure is 155psi, the PCM could tell the regulator to drop the line pressure.. A whole mish mash of things, as you can see.
I don't know, not having worked on trans for 30 years, what they are using that would be common, i.e. not inside the transmission, such as the TPS, or other sensor, that would stay in the car while you swap transmissions. There are things that affect the transmission that stay with the vehicle. Engine coolant temp sensor, Throttle Position Sensor, are just two off the head examples. Could they cause your flare and burp? I don't know. I just don't know what is used by the PCM to adjust all it's things... Just have a basic knowledge of trans and computers and engine control components. "I am not an engineer, but played one on 'building hoover dam' soon to be in a theater near you " Ha.
Ask your district rep, as he/she's the person you should be talking to. Also ask the local independent trans guys - they have a network. Check TSB's.

tom

 

OK Tom, thanks again for the info!

 

UPDATE:

Today, the Ford Motor Dealership where I purchased my wifes 2009 Escape, informed me the 6F35 transmissions [like in my wife's 2009 Escape ]have a defect.

The 6F35 transmissons have a "shift flare" condition that (to date) Ford has no fix for!

BEWARE!

I purchased a 2009 Ford Escape on 9/12/2008.

The transmission FAILED after only 300 miles!!!

Ford replaced the transmission only to have the same "shift flare" problem AND, the replacement transmission blows transmission fluid from the filler tube!!
The Dealer re-adjusted the fluid level twice, and the fluid blow-by condition has not stopped!!


The Dealer said the engineers are aware of the 'shift flare' problem, but to date, have no solution for the problem!!

The Escape is my wife's, she is afraid to drive the vehicle! The shift flare is sporatic and unnerving, it feel's as if the transmission is shifted into neutral between shifts!

Ford Motor Company says they may not have a 'cure' till the 2nd. quarter of 2009!!!

The Dealer said other complaints are coming in about the 6F35 shift flare condition and we (wife & I ) have to live with it till Ford engineers figure out a 'fix' for this problem!!!



Buyer beware!

-RR03-

 

Maybe if you disconnect something, such as the speed sensor, it will go into 'limp home' mode, and shift reliably enough that you can drive it... with a warning 'danger danger danger Will Robinson' going off as you drive down the road... the revenge of the robots.
I do not understand how a product can get through design, test, etc cycles without discovering that it is defective.
I suggest that you talk to the local area rep, and discuss replacing the vehicle with one that works. Back a while ago in CA, my wife had a taurus that had a transmission that put it out of service more than in service. She should have been able to turn it in for another vehicle under the Lemon Law, but she didn't know how to push it. If it does not work as advertised, and provide 'reasonable and customary' service that it would be expected to provide, it is useless and defective. You may have some rights under state law, depending on where you live.
I also think that your dealer should be able to show you the TSB that identifies the problem and the proposed solution time line. I would not take him at his word, as the warranty clock keeps ticking no matter what. You lose potential use, but the warranty still expires the same as if the vehicle were in service.
Do you believe your dealer? Or do you think that he is relating a story to get you to go home and leave him alone, waiting for the warranty to expire? Check a little higher up in the Ford service chain for exact details. I think that Ford buys some of it's six speed automatics from a Gm/Ford/?? co-operated plant. If they had a problem like this in all those cars, you know well that it would be first on their list of things to get fixed. It is expensive for manufacturers to r/r transmissions, and replace those that have burned up...
tom

 

I have a 2006 Ranger with the 5r44e automatic sitting on the rack at the Ford dealer as we speak. The symptom was a 2-3 shift flare. They ordered a valve body for the transmission and successfully installed it. They test drove the truck and the problem wasn't resolved. Now they're about to tear into the transmission and see what they can find. This ought to be interesting.

 

My new Ford trans in my '98, with about 10,000 miles on it was flaring. A minor band adjustment (??? had the shop do it, not sure exactly) and a bit of some Justice Brothers additive ("Flare Be Gone"???) and no more flare.

Why do they flare? Some combination of engineering compromise on shift quality and poor developement prior to release, compounded by refusal to address the problem year after year after year.....