Trans slow shifts when cold but ok when warm

[Rev_Tim]

1999 Subaru Legacy 168K miles, 2.2L engine.
When I first start the car in the morning, it shifts very slowly into 3rd gear especially allowing the revs to climb before engaging. Once warm and once engaged, there is no slippage and it shifts just fine. I think the car may have sat for a while so guessing some of the seals may not always be fully expanded. I have drained and changed the ATF three times to make sure it's all fresh and am hoping the right additive might resolve or at least improve the situation but don't know which would be the best one to choose.
Any input as to what the problem might be or possible fixes would be appreciated.
Thanks

 

[Bgallagher]

Sounds pretty standard to me but what kind of fluid did you use? a full synthetic might help. Also, lubeguard red might as well. Might be worth throwing a bottle in. Ultimately it might just be something you'll have to live with. My Equinox can be like that when it is very cold otherwise it's fine.

 

[Chris142]

Rubber seals inside are getting hard. once they warm up they expand and work as designed. Will need a rebuild eventually.

 

[MolaKule]

Some PCU's are programmed for higher RPM transmission shifts until the fluid warms up.

 

[kschachn]

Yeah, even my old Sienna is programmed to inhibit the upshift when cold. It helps to warm up the engine faster and reduce emissions.

 

[buck91]

Every vehicle I've owned has shown slight differences in shifting between cold and warm- particularly in winter temps. Some were more pronounced and some were not, though.

 

[Rev_Tim]

I changed out to full synthetic.... so if the seals are rubber... than nothing is going to soften them up .... is this correct?

 

[LeakySeals]

Need to know what fluid you are using and what the factory fluid spec is. Hopefully is something simple like an ATF thats too thick/thin when its cold. Like for example Maxlife in a older transmission requiring DEX III. It might be too thin.

 

[edyvw]

Originally Posted By: Rev_Tim
1999 Subaru Legacy 168K miles, 2.2L engine.
When I first start the car in the morning, it shifts very slowly into 3rd gear especially allowing the revs to climb before engaging. Once warm and once engaged, there is no slippage and it shifts just fine. I think the car may have sat for a while so guessing some of the seals may not always be fully expanded. I have drained and changed the ATF three times to make sure it's all fresh and am hoping the right additive might resolve or at least improve the situation but don't know which would be the best one to choose.
Any input as to what the problem might be or possible fixes would be appreciated.
Thanks

You sure it is not programmed that way?
In my BMW manual it clearly states that shift between second and third gear will be delayed until engine coolant reaches certain temperature (does not indicate temp.)
Since I have Carly for BMW OBD and App I can fallow exact temp. when transmission start to behave normally and it is around 30 degrees celsius.

 

[Lubener]

Every auto trans that I have had, always was sluggish when very cold and improved when warmed up.Synthetic is worth a try. The only additive which helped "morning sickness" was Seafoam trans additive. I would have to be desperate to add an additive. I would never put it in a newer CVT or solenoid controlled unit.

 

[meborder]

Originally Posted By: Chris142
Rubber seals inside are getting hard. once they warm up they expand and work as designed. Will need a rebuild eventually.


I think you nailed it.

It sounds like a shift flare in that gear, which is really bad for the health of the clutches. Keep your fluid fresh and try to ease up on it when it tries to shift until it comes out of it. Other than opening it up, there is not much else you can do.

As an idea, is there a way to install a pan heater for the transmission? This might ease the symptoms and push the inevitable out a little farther by reducing the amount of time that it spends flaring in the cold.

Just a thought.

 

[Rhymingmechanic]

Are you saying that it stays in second longer, or that the actual duration of the 2-3 shift is longer when cold?

Like a few people have said, many cars are programmed to hold gears longer in the cold to aid warmup. This goes back to at least 2001 in GM vehicles, as my pickup does it. I think there's even a note in the owner's manual about it.

Also, is this behavior new this year, or is the car new to you?

 

[meborder]

From the original post

Originally Posted By: Rev_Tim
..., it shifts very slowly into 3rd gear especially allowing the revs to climb before engaging. Once warm and once engaged, there is no slippage and it shifts just fine.


I read this as a description of a shift flare where the revs climb in an uncontrolled manner during the shift event.

 

[Rev_Tim]

When this occurs, as the car shifts from second into third.. it takes about 1 to 1.5 seconds and depending upon how much throttle, the rpm's increase until the shift is complete. Naturally, I back off the throttle to mitigate the condition. Once warmed up and in use, everything shifts normally through the gears.

 

[meborder]

Delayed shifts are to be expected. Slow shifts and shift flare is another matter.

Most likely hardened seals in the trans. The only fix requires removal and a rebuild.

Keep the fluid fresh and ride it out until it is unlivable.

Have you tried shifting it manually in the cold? Perhaps shifting it later might make it behave better.

I would try a magnetic heater to see if that helps, if it were mine.