Do automatic transmissions need to warm up?

[supton]

Yes and no? Cars prefer to be warm before being pressed hard, everything at proper temp. Thing is, driving gently goes a long ways to warming up faster--and idling a car does nothing for heating up say wheel bearings.

My old '99 Camry needed a good 30 seconds of idle before it would properly go into drive after sitting overnight, worse when cold. Something internally was leaking down... but at its age, 30 seconds of idling while buckling up, getting the radio right, etc was hardly much of a cost. Worse was the morning sickness that the steering rack had, in cold weather it would moan and eventually run out of juice--but after 5 minutes or so of driving, it apparently heated up enough that there wasn't an issue after that.

What others have said is true, ATF getting heated by coolant (or vice versa), torque convertor lockup is locked out until a certain temperature, overdrive locked out, etc. For the most part, just get in and drive, it'll take care of itself for you.

 

[D60]

My experience: if it moves and doesn't slip, nah. But that doesn't mean you get to drive it hard.

Old 46REs and my old 1990 E4OD often just won't really move with cold and high miles. Give it a minute to circulate the fluid and it's fine.

OTOH my '07 4R70 and '11 6R140 will happily drop into gear immediately.

So again, if it works, it works.

CVTs ‐‐ I dunno, but I'd go easy!

Finally, we have the technology -- it's called a block heater and they're available for almost any engine. And yes, warmer antifreeze will of course speed the warming of the ATF unless you have ONLY a standalone cooler or maybe a thermostatic bypass.

 

[Mechanician]

The torque converter generates the most heat in a transmission.
"Brake torquing" a car will make the fluid temperature climb quickly.
I've always assumed that's the reason the converter lock up doesn't function when cold, to help warm up the fluid.

 

[BrendanC]

my 05 accord won’t even go into drive until ATF comes up above 70° then it will fail to shift into 3rd. i’ve settled on letting it warm up for 10 minutes in the morning so i don’t have to pull over and clear codes to get the transmission out of limp mode. that being said it’s in the 400k range and i believe it to be original.

 

[Elkins45]

My experience: if it moves and doesn't slip, nah. But that doesn't mean you get to drive it hard.

The car in question is Scion xB. It's a granny wagon. I wouldn't be driving it hard under any conditions.

Looks like the consensus is that unless it does something weird then just drive it gently like I always do.

 

[Fordiesel69]

The tried and true ZF 8 speed in the dodge platform vehicles require 100 degrees F to shift as the manufacture designed it to. There are software adaptations that allow for acceptable shifting well above and below that range. When stone cold such as when it was -9F last night my ZF shifted very strange. As soon as the temp warmed up to 70F it was perfect. This is normal and why you must be gental and not road race or pull a trailer with the pedal to the metal as they say.

My 6F55 had a harsh downshift this morning as whatever inside didnt want to move as fast as it normally would.

 

[Propflux01]

My Mazda CX5 shifts (takes) longer and slower when cold. When I start I let it do its 20 second high to low idle thing, then shift, and drive slow (usually 1500-ish rpm) until the coolant starts to rise. By the time the coolant gets to temp the tyranny is shifting normally.

 

[BrianF]

The 4L60E in my 2006 Trailblazer does not bad cold. But cold for instance was -37c a few days ago. I take it easy for a few miles before I hit the highway. Biggest thing is the low temperature will keep lockup from working.

It's still sporting some Amsoil and Maxlife low viscosity ATF that I out in around 2014.

 

[nascarnation]

At Allison all our commercial stuff is validated after soaking 24 hours at -40F.
Fluids do vary. The Petro Canada Dex III flowed better than the GM Dex VI but not as good as TranSynd. This was 15 years ago so not relevant to what you can buy today.
It really comes down to can the pump suck it out of the sump.

Military spec is -60F soak which is a lot tougher but they give you MIL - 46167 PAO based fluid so it's workable. That stuff would stink up the whole test cell.
Their operating scenario was fighting the Russians in Alaska in winter time.

 

[FoxProTwisty]

Take a bottle of ATF sitting in your garage when it's below zero and try to take a slurp of it through a cocktail straw. No it doesn't taste like fruit punch, but it is a good lesson in fluid dynamics.

Yeah it needs to warm up. It's not sitting at grade and will not perform as such until it is.

 

[eljefino]

You radiator has internal lines in which your transmission fluid runs through, this is meant to act as a temperature regulator...help warm the fluid in winter and cool it in summer.

Common misconception. It's just a cheaper trans cooler to have a loop of oil go through another fluid (antifreeze) vs being an air-to-oil cooler. The radiator on a cool day can be under 100 degrees after an hour of driving because the engine thermostat doesn't send much coolant out for cooling. Most transmissions have their own thermostats to bypass the cooler when needed.

 

[ctechbob]

The Transit 10R80 will not shift properly & takes 7-8 seconds to go from drive to reverse when it's stone cold. I've resigned myself to giving it 4-5 minutes to shake off the cobwebs before trying it.

A dose of LG Platinum might get the valve body moving properly for you. Bunch of us in the Ranger 10R80 land are having very good success with t.

 

[wlk]

I give my vehicles about 5min to warm up in the winter and even longer as it was -3°f. Windows need to defrost, and if you don't let it warm up in our trucks first, you will not have heat for a long time, 350sbc and 460bbf. The Honda gets about a minute or 2, garage princess, unless the windshield is frosted up then more time until clear, but she heats up easier than the other 2.

 

[AdmiralYoda]

I just topped off my wife's 2016 Mazda CX-5 with a half quart of 5W-30 the other day when it was about 0F out. I pulled the oil bottle out of the garage where it had been -10F just a few hours prior. It poured like Lucas Oil Stabilizer!

I vote in <10F warm your car up for a couple or 5 minutes and your good to go. The transmission takes longer to warm up so take it easy for a few miles and then go for it. Is this necessary? Probably not. Will it hurt or help anything? Probably not. But my truck shifts like crap when it is cold and drive it hard right away and I can spare the extra 10 seconds in my commute for taking it easy for a mile.

 

[nomas]

So after two pages or more , we have Yes , No, and This is what I do ... Par for the course on BITOG .

 

[Marcozi]

So after two pages or more , we have Yes , No, and This is what I do ... Par for the course on BITOG .

I think the best recommendation is to allow the engine to idle for about 30 seconds (more if it's reeeely cold) and then drive the car gently for a first couple of miles.

 

[Hall]

So after two pages or more , we have Yes , No, and This is what I do ... Par for the course on BITOG .

Hey, at least the majority of answers are from people that appear to live in northern states where it actually applies. If folks from Florida, Texas, etc responded based on it being "cold", well, many of us would skim over those opinions !

 

[D60]

At Allison all our commercial stuff is validated after soaking 24 hours at -40F.
Fluids do vary. The Petro Canada Dex III flowed better than the GM Dex VI but not as good as TranSynd. This was 15 years ago so not relevant to what you can buy today.
It really comes down to can the pump suck it out of the sump.

I learned this on my non-profit's '08 Ally where they love to drop the filter. On cold Colorado mornings sitting in the shade of the rising sun, it simply wouldn't move.

Fast forward to middle of the day ‐‐ usually even our winter days approach 40F -- and it would drive normally.

Took awhile to figure it out, but when I dropped the pan the filter was just resting there in the pan. Smoking gun.

 

[SwampSurvivor]

'Need to'

Probably not.

But fluid being thicker can make them shift funky when they're cold since solenoids/valves won't be moving as fast as maybe the ECU expects, so it probably isn't a good idea to romp on it out of the gate until it starts coming up to temp.

Late 2000s, I had a Ford Taurus that did NOT like the extreme cold. Anything below -10 (which we used to get a lot then) and it would take 3-5 seconds to engage revers / drive. Made backing out of the driveway on a cold morning interesting.

The other problem I had - which was fully self induced - is the transmission wouldn't lock up the torque converter because of the giant cooler I had. It wouldn't get up to temperature.

 

[Rmay635703]

My experience: if it moves and doesn't slip, nah. But that doesn't mean you get to drive it hard.

Old 46REs and my old 1990 E4OD often just won't really move with cold and high miles. Give it a minute to circulate the fluid and it's fine.

OTOH my '07 4R70 and '11 6R140 will happily drop into gear immediately.

So again, if it works, it works.

2001 Dodge 5.2 the auto is very slow to shift into reverse the first time on very cold days, idling doesn’t seem to heat it.

I just shift into reverse, release brake and let it idle itself into motion, letting it slowly build up heat pressure enough to move has worked 10 years, once it does this it drives mostly normally without lockup or OD.

Funny part is my motor oil selection Seems to affect shifting for god knows what reason, I am thankful being MOPAR that it still works