Automatic Transmission Service

[RayH]

You drop the drain pan to change the filter. Its not really a part of the flush process but its usually done in conjuction with it.
If you just drain the pan, you only recover about half the fluid. A flush changes practically all the fluid. If your tranny fluid looked good and clear and didnt smell burnt, I would say just drop the pan the change the filter, but since its "brown", flushing it is probably a good thing.
You should be asking yourself (you a service tech) why a truck with only 50000 miles on it has "brown" tranny fluid. In a truck with that low of mileage, brown or burnt fluid usually indicates that the tranny has been overheated, has been slipping or it has ingested some water.

 

[Redbug]

Hi George,

The reason a flush is good, (in addition to also having the filter changed), is because it replaces the oil in the torque converter. Just draining the transmission oil does not drain all the old oil out of the torque converter. It's a good bit of oil.

Here's an interesting site. Scroll down to the lower right hand column...there's a section of flushing... Transmisions

 

[RayH]

Here's an interesting site. Scroll down to the lower right hand column...there's a section of flushing... Transmisions

I didnt read the whole site but I would caution anyone about believing information from any transmission site that cant spell transmission correctly.

 

[kenmac]

I change my tranny fluid from time to time. I installed a drain plug in the tranny pan to make it easier, but, like it has been said . You can't get all the fluid out with out a flush or removing the tranny & taking it apart.When I change my fluid (& filter) I will run a few hundred miles & change the fluid only in hopes of getting out some of the old that has mixed with the new

 

[N80]

You should be asking yourself (you a service tech) why a truck with only 50000 miles on it has "brown" tranny fluid. In a truck with that low of mileage, brown or burnt fluid usually indicates that the tranny has been overheated, has been slipping or it has ingested some water.

Well, first I suspect they tell anyone who is past due for a change that their fluid is brown and of course they say the word brown the way a doctor would say 'mass' or tumor. Second, how brown is brown? I can't say that I've ever seen new automatic transmission fluid, but it wouldn't surprise me if it wasn't slightly amber and maybe mine is now dark amber.....which is 'brown' to a mechanic. (I never actually saw it. And remember, the power steering fluid was 'brown' too and the manual does not indicate that it ever needs changing, much less flushing.) Third, the service interval is30k miles so I have neglected it. Maybe that made it a little brown too.

But, this truck has had the lightest duty of any vehicle I've ever owned. And it is running and shifting just fine. So I don't think it has a tumor.

JD, that article was interesting. Not only am I going to have my blinker fluid changed...I'm going to demand that the blinker system be flushed as well!!!

 

[Bird]

I've ever seen new automatic transmission fluid

It might be worthwhile to open a can, even it goes to waste, or to pull the dipstick on a fairly new vehicle to get an idea of what it should look and smell like. If yours smells burnt, then that's really bad, but in my personal experience, that's relatively rare.

 

[RayH]

It might be worthwhile to open a can, even it goes to waste, or to pull the dipstick on a fairly new vehicle to get an idea of what it should look and smell like. If yours smells burnt, then that's really bad, but in my personal experience, that's relatively rare.

Agreed, tranny fluid is no where near brown when its new. Its actually a very bright red. It only turns brown when its contaminated or burnt. And it is unusual for a newer vehicle with so few miles to have brown, or brownish or anything but bright red fluid. Thats why I said this is something you should question. You shouldnt take offense at that, none is meant. Im just saying that if its brownish, thats not usual even if you did skip some maintenance.
Ive got two older vehicles with automatics, one with 133000 and the other with 106000. The fluid in both of those is bright red. A vehicle with 50000 should not have anything resembling brown fluid in the tranny.

 

[DieselPower]

Just a little note on the color of "new" ATF oil. It might not be bright or light red. The color is only a dye and depending on what the lubricants manufacturer uses it could be any color. The ATF I sell is a very dark red. I have also seen amber (un-dyed), purple and even green. I recomend you take Bird's suggestion and check it after you have it changed. Get familiar with what it looks like and smells like when it's new so you can spot any possible problems in the future.

 

[PSDStu]

Just got done changing the tranny fluid and replacing the filter on my 97 PSD and although it's a messy job without a drain plug I am at least lucky that my tranny has a drain plug for the torque converter, so I get most of the old tranny fluid out and with the pan dropped can wipe it clean and inspect the drain pan magnet.

I like doing my own maint and I understand that some folks don't have the time or desire to do there own maint.

 

[Egon]

Just for interest: Some new vehicles do not have dipsticks on the auto transmission??