Do You Change Tranny Fluid Warm or Cold ?

[Idrinkmotoroil]

Going to change my transmission fluid tomorrow on my 01 Caravan - 4 speed auto, is there any requirement to change the fluid hot or cold ?. I would think I might get more fluid out if it was cold and had time to drain into the pan overnight. Since we only get about 1/3 of the fluid out during a pan drop I'd like to get as much of it as possible. So do you do it hot or cold ? or it doesn't matter ?

thanks

 

[HardbodyLoyalist]

I've always done it cold just because I don't like hot fluid running down my arms or, worse yet, brushing my forearm up against a hot exhaust pipe.

I've never really thought about whether I was getting more or less fluid out.

 

[Idrinkmotoroil]

yeah that is another concern since you are likely to spill some fluid taking out the pan, I'd prefer doing it cold.

 

[Vspec]

I own a 6spd Manual and I've always done it Hot or Warm. My Factory Service Manual says to take the car for a drive to stir the transmission. I let it drain a good hour or two.

 

[Bobio]

I can't imagine doing it the old fashioned way of dropping the pan to drain the fluid

The 4R70W also has an access port in the housing to get to the TC drain so a fluid change is about as painless as an engine oil change.

I generally change the fluid cold so that as much of it as possible has time to drain back into the pan.

 

[Bror Jace]

I can't see doing it cold. I want as much of the contaminants stirred up and in suspension when I drain it.

I like it hot, sloppy and weird.

And I wear my burns like badges of honor.

--- Bror Jace

 

[doitmyself]

Is the "filter" on the 4R70W have any type of media in it or is it just a fine screen.

If it is just a screen, I can't see dropping the pan to change fluid, unless you have a neglected system.

Thanks for the picture, Bobio.

 

[Kestas]

Doitmyself, I understand what you're saying about some filters just being fine screens, but if you don't drop the pan, you won't be able to clean the magnet or fine silt that collects at the bottom of the pan.

Idrinkmotoroil, if you want to drain more fluid than you can by just dropping the pan, there is a DIY procedure to exchange all the fluid, written many times on this board.

 

[Idrinkmotoroil]

thanks Kestas, but I thought I would swap it out with the 4-5 quarts factory method and give it a slow cleaning approach. Doing the filter and cleaning the magnet helps too. I make a **** of a mess anytime I change fluids on my vehicles I think I'd have an oil slick in my driveway using the full change method. things never work as they should with me, so changing 4 quarts is risky enough for me.

 

[Ray H]

Some automatic transaxles have NO pan or filter and the internal mesh screen is accessible only at teardown. The ATF is retained by a threaded plug screwed into the cast aluminum case.

 

[TomH]

I've never owned an automatic equipped vehicle, but I change gear lubes when they are warm/hot. Just feels to me like more drains out when warm than when cold.

 

[99]

quote:

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Originally posted by Idrinkmotoroil:
Going to change my transmission fluid tomorrow on my 01 Caravan - 4 speed auto, is there any requirement to change the fluid hot or cold ?. I would think I might get more fluid out if it was cold and had time to drain into the pan overnight. Since we only get about 1/3 of the fluid out during a pan drop I'd like to get as much of it as possible. So do you do it hot or cold ? or it doesn't matter ?

thanks

---

You don't want to do it hot unless you have a drain plug in your trans pan.....hot transmission fluid sucks when it hits the skin and there's no way to avoid it when dropping the trans pan. I drive whatever it is I'm changing the transmission fluid on around the block just to get things a little warm and then drain it.

 

[baomo]

i always change it cold and check the level as it warms up.

 

[99]

Never check the auto transmission fluid level cold or when it's even warm. You want it up to full operating temp/hot because ATF expands alot when heated.

 

[Eddie]

I always change my Subaru warm (not hot) as I feel I get some flushing action. I addition I have an old fasion transmission that has a drain plug and an extermal filter. 2000 Subaru forester 4 spd. auto

 

[FazerZ]

quote:

---

Originally posted by doitmyself:
Is the "filter" on the 4R70W have any type of media in it or is it just a fine screen.

If it is just a screen, I can't see dropping the pan to change fluid, unless you have a neglected system.

Thanks for the picture, Bobio.

---

The factory 4R70W filter is a Filtran/SPX made plastic/metal unit with a fiber "microfelt" media. It should be changed when you have the pan down. Avoid the big part stores kits due to the use of knock-off overseas filters.

DH

 

[mike1qaz]

I have a drain bolt, so I always drain hot.