How critical are ATF changes towards durability?

cangreylegend · Sep 2, 2003

I recall once that I saw somewhere that a tranny rebulder said that if people simply changed their ATF regularly, he would be out of business. Any brand of ATF, just as long as the proper type was put in.

I know we are biased on this forum but how true would that statement be really regarding long tranny life?

sub_zero · Sep 2, 2003

Just my experience:

No failures but I just changed the fluid in my Sierra after 120000 km and it was thick and nasty looking. The vehicle shifted much better after that.

crashz · Sep 2, 2003

Automatics wear out eventually either way, however by properly maintaining the tranny and keeping it cool, its just like an engine, it will go for a very long time. Heat is the #1 killer of autos and ATF, so keeping it cool will save both. At the very minimum, change your ATF per your owners manual. I change mine per the severe service (every 30k with semi-syn. Mercon V) and so far my Ford transmission works perfectly. I fully expect to see 200k-300k
on this vehicle before it needs any attention.

Eiron · Sep 2, 2003

I've recently become convinced that regular ATF changes are a good thing. The "regular" service interval for my car is 60k mi, & "severe" is 30k. We don't tow anything or drive in the mountains very much (maybe 2 or 3 times a year), but when I changed it at 35k it was already turning brown & burned. Since I can only change half the fluid each time, I've decided to switch to synthetic & change it every 10k mi.

Ken2 · Sep 2, 2003

1) A transmission sheds clutch friction material particles which can accumulate and clog things.

2) A transmission sheds steel and other metal wear particles which are very abrasive. Many transmissions have no actual filter or an ineffective filter.

3) ATF, like any other oil, can become oxidized and lose it's lubricating qualities. This happens faster with high heat.

4) Clean, fresh ATF prevents lots of problems. Along with this, keeping the clean ATF cool during towing or heavy hauling by the installation of an additional cooler is very wise. I like to add a filter in the ATF cooler line. I use either the small in-line filters from Magnefine or SPXFiltran, or a large spin-on transmission filter from Racor, the six micron LFS22825. Opening one of these Magnefine filters after several thousand miles is an eye-opener. The amount of steel particles stuck to the magnet (even if the car also has a magnet drain plug), and other particles in the filter element, are interesting.

Also, the additional cooler helps prevent hot ATF from baking the rubber-like seals in the transmission. 150-180°F is a good temperature for ATF.

Ken

[ September 03, 2003, 11:18 AM: Message edited by: Ken2 ]

cangreylegend · Sep 3, 2003

Ken, regarding point 1. Been there, I had to clean out shift solenoid screens.

point 3. Since I change ATF/ drain and refill each year, I imagine it's better to do so at the end of the summer after the high heat. In winter, I suspect the ATF doesn't degrade so readily.

point 4. How restrictive are those Magnefines? is it sufficient to affect lockup clutches?

Fillherup · Sep 3, 2003

Hi, I just looked at my Camry V6 auto and it seems to have a stock tran cooler. It this normal for most sedans? I thought I would have to add one. I wonder how well it works since the hoses go into the lower part of the rad? Thanks

crashz · Sep 3, 2003

Most auto's have a cooler within the radiator, using the coolant to transfer some of the heat from your tranny. This is not very effective in my eyes, because the tranny could only be cooled to the water temp. And every one knows water tempt can get up to 220 even in the radiator. At 220 your tranny is cooking and the fluid is turning to varnish. An additional cooler (looks like a small radiator without side tanks) can be used to further cool the fluid.

I have a cooler and haven't decided weather to completely bypass the radiator cooler or use in in conjunction.

Robbie Alexander · Sep 4, 2003

quote:

Originally posted by Eiron:
-snip-
Since I can only change half the fluid each time, I've decided to switch to synthetic & change it every 10k mi.

Keep it PINK and Keep it COOL:
keep it PINK and keep it COOL:
KeEp it Pink and Keep it COOL:
kEeP it Pink and keep it COOL:
Do this and it will last a long time.

Buy a tranny cooler!
As far as changing only 1/2 the fluid, why would you do that? If you mean that 1/2 would stay in the tranny then I'd say to consider a complete flush with those machines,

BG has a tranny flush, and I would suggest their Conditioner too, not just the flush, you may be surprised how long it last, but at least it will get CLOSE to 100% of it out. The service is expensive (??120-150) but if you have it done once, and you can get a salesman from BG, I think you could do the changes with a better fluid (Ithink $32 a gallon). I'm only going by what others have told me, and

the only fluid I have used of theirs is the PowerSteering, and it looks as fresh as when it went in Over 100K ago, and although I'm sure it's gotta be wet by now, the salesman told me that it would go 2-3 times as long as a normal fluid and that their WET was higher than Almost anyones dry on the market and since a normal fluid is usually wet in 1-year or there abouts, then I figure I'm about 1/2 way there.

JohnBrowning · Sep 9, 2003

Use a good synthetic ATF and change it at 18k-30K mile intervals! I am partial to Redline ATF. I think it is bar none the best!!! I am also partial to drain plugs. You do not need to change the filter ever time you change the fluid. THis is of course depending on schedule you follow. I had a compact truck with an extremly high output small block and a tricked out 700R4 I helped build. I drove the pi$$ out of that truck and changed fluid often. I used regular trany fluid and would drain and refill ever oil change. It would be silly to chang the filter or drop the pan that often!

Ken2 · Sep 9, 2003

quote:

Originally posted by crashz:
Most auto's have a cooler within the radiator, using the coolant to transfer some of the heat from your tranny. This is not very effective in my eyes, because the tranny could only be cooled to the water temp. And every one knows water tempt can get up to 220 even in the radiator. At 220 your tranny is cooking and the fluid is turning to varnish. An additional cooler (looks like a small radiator without side tanks) can be used to further cool the fluid.

I have a cooler and haven't decided weather to completely bypass the radiator cooler or use in in conjunction.

The coolant in the bottom of your radiator is probably much cooler than 220°. That's probably the temperature of the coolant coming from the head, the hottest part of the engine. The top of the radiator gets this hot coolant, then cools it as the water passes down (or across) the radiator. It's much cooler in the bottom of the radiator from where it then goes to the engine. Remember the function of the thermostat...it sends a portion of the hot engine coolant to the radiator to maintain a constant cylinder head temperature, and that portion of the coolant is replaced with cool stuff from the bottom of the radiator. Sure, if you're running really hot and the 'stat is wide open, and the day is hot, then the entire system is hot, including the ATF

In this case, particularly if you're running hard, an air-cooled ATF cooler is very wise.

Ken

[ September 09, 2003, 07:18 PM: Message edited by: Ken2 ]

badnews · Sep 9, 2003

So what would be an ideal temp for the fluid?

Ken2 · Sep 9, 2003

155-170°F

Robbie Alexander · Sep 11, 2003

quote:

Originally posted by JohnBrowning:
--snip I drove the pi$$ out of that truck and changed fluid often. I used regular trany fluid and would drain and refill ever oil change. It would be silly to chang the filter or drop the pan that often!

Course if you change it often, this would be fine, but like a lot of people, they wait til it's no longer PINK. I should say that it's colored, to say the least.

Any way
How long do you get on an AUTO tranny? before they need replacing, and do you have some methof to work on the PS ?

S2000driver · Sep 14, 2003

I'm glad Honda makes it easy. No drain pan to drop. No mess. Yes, I'm talking about thier auto trannies.

Every 30,000 miles, remove drain bolt, wipe off drain bolt replace drain bolt, add ~3 quarts. ANYBODY can do it, costs about $10.

Never had a tranny hiccup in my 20 years driving.

[ September 14, 2003, 12:30 PM: Message edited by: S2000driver ]

Bryan_1NZ-FE_Mobil 1 · Dec 21, 2003

quote:

Originally posted by cangreylegend:
I recall once that I saw somewhere that a tranny rebulder said that if people simply changed their ATF regularly, he would be out of business. Any brand of ATF, just as long as the proper type was put in.

I know we are biased on this forum but how true would that statement be really regarding long tranny life?

Yup, by changing your ATF regularly, it definately prolongs the life of the tranny. Use what is only recommended though. For my Toyota, it is specified that ONLY Type IV is to be used. Even the authorized agent used an aftermarket "Arrow" brand for my Corolla and it had rough shifts. After I changed to factory fill, the tranny became smoothe again.

Les · Dec 21, 2003

Let me see if this picture works. You know a picture is worth ...

twentynine · Dec 22, 2003

Proper service is the life of a good transmission.

Spector · Dec 22, 2003

quote:

Originally posted by Bryan_1NZ-FE_Mobil 1:
Use what is only recommended though. For my Toyota, it is specified that ONLY Type IV is to be used. Even the authorized agent used an aftermarket "Arrow" brand for my Corolla and it had rough shifts. After I changed to factory fill, the tranny became smoothe again.

You must have a newer Toyota. Mine says Dexron II and I have been using Amsoil ATF for ten years now. However, this is one reason I will never buy another Toyota or Honda. I hate manufacturer specific fluids and refuse to buy into them. Had the coolant changed on mine (it came with the green ethelene glycol) and the dealer put in that **** Toyota Red Long Life (which is not compatible with anything else) without informing me that is all they sell. I complained to no end but they said that is all they stock reagardless of when the car was built. As a result I now have three different coolants on the shelf for top offs. Never again!!!!!!!

JohnBrowning · Dec 24, 2003

Spector, My family has been useing GM Dex-cool compatable coolant to top of the Toyota stuff since Toyota came out with their long life. We have not had a single coolant related problem doing this! When we worked on my Dads 95 1/2 Tacoma we flushed and refilled with Dex-cool. My Moms Tundra was also toped off with about 500ml of dex-cool!

A lot of pricate shops just carry Dex-cool in 55 gallon drums reguardless of make. I know of a world class body shop that uses Dex cool in 55 gallon drums for everything. It is more cost effective for them to flush and refill an entire coolant system with dex-cool then it is to keep all of the different fluids on hand! Their OEM work is mostly Daimler Chrysler and they use this in them. THey even do this with million dollar cars unless specified otherwise by the owner.

How critical are ATF changes towards durability?

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