Tranny Temperatures

[fly300kts]

I played with VAGCOM this week end and while browsing the different logs, I saw the tranny oil temperatures : above 200F
After some research, the cooler you can keep the oil temperature down, the longer you will keep your tranny. Today, the tranny oil cooling is done by an exchange water/oil and since the tranny radiator is attached to the water radiator, having the water cooled down to 200F in normal operation, I can't expect any better.
Since I installed the AWE intercooler last week, I have now plenty of room by the right side scoop and I start to think installing an additional Air/Oil radiator in this area, with custom lines.

Now comes the questions:

Does anyone have done this mod in the past?
Type of radiator installed since there is so many available?
Temperatures logs after install?
Did you keep the original setup and added the radiator to the circuit or simply condemned the original system

Any feedback would be great

Phil

[CorneliusRox]

Wow those temps seem really high! Is that just how our cars run or do you have a problem somewhere?

Sorry, I dont have any useful info for you, but good luck getting those temps down.

[Mc Suly]

There are some people who installed those oil inter-coolers im sure they will chime in!

I saw one on ecs tuning thought not sure if good or not

[fly300kts]

Wow those temps seem really high! Is that just how our cars run or do you have a problem somewhere?

Sorry, I dont have any useful info for you, but good luck getting those temps down.

No problem at all, that's the way they run

Phil

[wildcat333]

I have no useful info to share, but I am interested in this, so I'll be lurking on this thread. Interested to see where this goes.

[Inked]

Phil can you elaborate on the benefits of this? If this is how the tranny normally operates and since we don't have trannys that are really known to fail, I am just wondering why this would be important.

[Stewy]

Wow, that does seem a little high, especially for a manual. Perhaps a universal kit from someone like B&M?

http://bmracing.com/?wpsc-product=po...u-11x4-12x1-12

[jimrobbington]

I can't believe Phil started a thread asking a question? I never knew there was anything you didn't know. A shame, too. If you don't know, then I'm sure none of us can help (as also proven by the very helpful responses so far.) I guess there are downfalls to being one of the most knowledgeable people on a forum; no one can help you!

[Inked]

What JR said were my exact thoughts when I first read the thread LOL

[Charles.waite]

Is it always better for the trans to run cooler? Wouldn't it affect the viscosity of the oil in it, etc? I'm just thinking how its so critical to make sure the oil is at the correct temp putting it into the trans, the operating temp of the fluid would be just as critical...

[doublezero30]

this doesnt really answer your question but...

my thinking is that engines run above 500F day in and day out...i would think a tranny could handle 200F without an issue. its not like they are extremely brittle. and these arent prostock track cars. Personally i fell like youll be alright. I feel like if you needed a trans cooler, audi would have provided you with one off the line.

[fly300kts]

An automobile that has an automatic transmission cooler tends to last longer than one without the system.
The transmission fluid in an automatic transmission cooler goes through a small radiator that cools it. Generally, the small radiator is found close to the main radiator that cools the engine.
There are three important functions of an automatic transmission. It cools, lubricates, and hydraulically operates the transmission system. Cooling the transmission is important to prevent damage of the gaskets and rubber seals. Warping of metal parts can also interfere with transmission. There are some applications that make the transmission undergo more stress. The automatic transmission also suffers wear when the vehicle is driven in either heavy traffic or snow.
For every 20° drop in temp, the life of the tranny doubles. There are limits to that of course (I wouldn't go below 120°F or so), but for the most part, cooler is better.
You need to upgrade your car’s automatic transmission cooler if you plan to perform strenuous jobs frequently. The fins on the small radiator in an automatic transmission cooler determines the transfer of heat, hence they are used to rate different cooler systems. Having a relatively larger radiator makes the automatic transmission cooler more effective.

I was looking at something more sophisticated like the unit here below, who has a fan built in with an adjsutable thermostat.



Talking to a Tranny shop today, the temps I am seeing are still low. The guy told me to run the logs during summer, especially under the florida heat. I will see close to 300F. I am starting to understand why the OEM tranny oil is expensive

Phil

[fly300kts]

this doesnt really answer your question but...

my thinking is that engines run above 500F day in and day out...i would think a tranny could handle 200F without an issue. its not like they are extremely brittle. and these arent prostock track cars. Personally i fell like youll be alright. I feel like if you needed a trans cooler, audi would have provided you with one off the line.

I agree with you but let's keep in mind that I am now far away from a virgin A4, that's what concerns me

Phil

[fly300kts]

I can't believe Phil started a thread asking a question? I never knew there was anything you didn't know.

Not yet but working on it LOL

Phil

[jimrobbington]

Phil, you have auto transmission? That I did not know, if true it is. I know that on big trucks that get chipped, I'm pretty sure they have to upgrade transmission cooler. Where's CorneliusRox when you need him?

[DRAKLORE]

You drive an automatic???

Anyways, here's my thought on the issue. I used to do something similar as a TSB on some of the big diesels that came through the dealership.

Proof of concept:



And lastly I think this GT-R pulls it off the best


Now of course you don't have to boldly throw it on the front like that if you can hide it in the side duct...

[Inked]

Phil, you have auto transmission? That I did not know, if true it is. I know that on big trucks that get chipped, I'm pretty sure they have to upgrade transmission cooler. Where's CorneliusRox when you need him?

It is popular to upgrade to the lighter, higher speed Flexalite fans on trucks...

[fly300kts]

You drive an automatic???

Anyways, here's my thought on the issue. I used to do something similar as a TSB on some of the big diesels that came through the dealership.

Now of course you don't have to boldly throw it on the front like that if you can hide it in the side duct...

Yes, Tip here Drak
Thank you for the feedback and I am still searching from previous projects done on Audi's since I still have a lot of unanswered questions

Phil

[swoardrider]

Phil,
Is our ATF actually going through a section of the radiator, like a lot of American and Japanese cars (radiator and tranny cooler one unit)? Or does the A4 have its own separate tranny cooler that mounts to the radiator?

I too would be interested in this, as I have gotten the tranny so hot on the Streets of Willows Racetrack, that the car actually went into limp mode, and the CEL came on. This has only happened once in all the years of track abuse, and only after a 45 min lapping marathon in 95 degree Mojave Desert heat, but it did make me wonder how much life I may have taken off of the tranny.

I have read that people with the all-in-one radiator/tranny cooler have bypassed the all-in-one completely, and have gone with a good quality stand-alone cooler with good results. Only potential drawback some say, is that in cold climates the tranny fluid doesn't come up to correct operating temps, which can open up a whole different can of worms. Hence the reason most OEM designs run thru the radiator, to warm up the fluid quicker.

[Charles.waite]

Only potential drawback some say, is that in cold climates the tranny fluid doesn't come up to correct operating temps, which can open up a whole different can of worms. Hence the reason most OEM designs run thru the radiator, to warm up the fluid quicker.

That makes a lot of sense. So under light stress or at really coold temps the trans could operate TOO cold and possibly experience more wear than at normal temp.

[JPT]

That makes a lot of sense. So under light stress or at really coold temps the trans could operate TOO cold and possibly experience more wear than at normal temp.

Yes. This is true. I did an auto swap on my wrangler with an auto trans from a cherokee. I didn't run it through the radiator (since I had a manual the factory radiator did not have the lower trans cooler), I had run a trans temp gauge, I noticed that it would take quite sometime to get up to temp.

When i was towing with the jeep, the most I ever saw was 250*, and that was towing my 1200 cc motorcycle on my 500lbs 4x8 trailer in the summer. typically it would stay around 150* without the load. So hearing temps over 300* seems a bit shocking to me, as that would typically cook clutches...

Now I want to add a trans temp gauge to the car... Maybe someday when I add a boost gauge...

EDIT: I have never understood why auto vehicles (excluding trucks) never come with trans temp gauges in the dash. It is so important to the sustained life of the trans. All they have to do, is add one with a blue to red (without physical temperatures) so when you see it getting close to the red, you know to get somewhere where you can maintain a fast speed, or shut it off (which isn't usually the best thing as you arent actually cooling it, just not making more heat)

[fly300kts]

Phil,
Is our ATF actually going through a section of the radiator, like a lot of American and Japanese cars (radiator and tranny cooler one unit)? Or does the A4 have its own separate tranny cooler that mounts to the radiator?

I too would be interested in this, as I have gotten the tranny so hot on the Streets of Willows Racetrack, that the car actually went into limp mode, and the CEL came on. This has only happened once in all the years of track abuse, and only after a 45 min lapping marathon in 95 degree Mojave Desert heat, but it did make me wonder how much life I may have taken off of the tranny.

I have read that people with the all-in-one radiator/tranny cooler have bypassed the all-in-one completely, and have gone with a good quality stand-alone cooler with good results. Only potential drawback some say, is that in cold climates the tranny fluid doesn't come up to correct operating temps, which can open up a whole different can of worms. Hence the reason most OEM designs run thru the radiator, to warm up the fluid quicker.

Yes, the colling today is done via a radiator section, on the right side to be exact. This mean that the oil temperature does not get cooler than 96C
You can also ask yourself how good is the cooling?
What I an planing to do is:

Keeping the inlet line to the OEM radiator
Oulet will be connected to the inlet aux. radiator
Outlet aux. to inlet tranny

Phil

[swoardrider]

Keeping the inlet line to the OEM radiator
Oulet will be connected to the inlet aux. radiator
Outlet aux. to inlet tranny

Phil

Makes sense to me. Derale's website shows this type of plumbing as well. I eventually want to get an AWE FMIC, and use the OEM SMIC air ducts for brake cooling, so this limits where I can put a tranny cooler. Do you think something like this will fit above or below the AWE FMIC? It's 2.5" high by 1.75" thick and comes in various lengths .

[fly300kts]

Yes it will fit but here is my concern with this type:
With the AWE installed, you start to get a petty big stack of components: Tranny cooler, AWE, AC radiator, Water radiator. Plus, the tranny cooler will be right in front of the inlet and outlet tube of the AWE, critical parts that you want to keep cool, especially the outlet side.
I am working on CAD drawing at this time trying to figure out how can I use the right SMIC as support

Phil

[DRAKLORE]

On some ford cars they combine the power steering and trans cooler into a small similar unit like posted above.

I can't remember, but I don't think many i any manuals have any cooler lines
Because the fluid wouldnt have any way to flow... Correct me if I'm wrong?

[mr shickadance]

could this be a result of the AWE FMIC taking up all of the radiator's normal cooling area?

[fly300kts]

could this be a result of the AWE FMIC taking up all of the radiator's normal cooling area?

No since the AWE is smaller than the water radiator where the tranny radiator is located

Phil

[fly300kts]

On some ford cars they combine the power steering and trans cooler into a small similar unit like posted above.

I can't remember, but I don't think many i any manuals have any cooler lines
Because the fluid wouldnt have any way to flow... Correct me if I'm wrong?

You are correct, no radiator on manuals. On auto, there is also an additional pump to circulate the tranny fluid

Phil

[DRAKLORE]

I believe the purpose of combining the power steering and trans into one cooler. Is to use the power steering pump to boost the flow.

[Mc Suly]

Any luck on this?

What about this

http://www.ecstuning.com/Audi-B7_A4-...ler/ES2221127/

[Charles.waite]

Hey Phil, I'd been meaning to post this up, but never got around to it. I've been having bad TC lockup issues related to a failing TC and Valve body (the usual crap a number of people on here are dealing with nothing special) and I recently noticed they'd almost completely gone away after I replaced my failed T-Stat. I'm pretty positive the issues were, in part, caused by the failed T-Stat causing the tranny fluid temps to be lower than normal. My T-Stat was opening really early (~50*C, I tested it after I replaced it) and it was causing 10-15 minute warmup times coupled with periodice drops in temp while under load.

Anyway I replaced it last saturday (a little over a week ago) and the revving issue has almost completely subsided once the car is warm, and it appears to be diminished at lower temps (probably due to the warm coolant making its way to the Tranny faster because the coolant loop is operating properly).

Anyway I wanted to throw this out there as a counterpoint to "colder is better" as you said above. I may not be seeing the whole picture, but its definitely some food for thought.

[fly300kts]

Any luck on this?

What about this

http://www.ecstuning.com/Audi-B7_A4-...ler/ES2221127/

Saw this one as well
I am kind of stuck at the moment with the project because I can't get confirmation of the exact fitting size of the two aluminum hoses attached to the side of the engine from the tranny tranny and connected to the flexbole hoses going to the radiator
Installing the radiator will require aadding fluid to the tranny and I do not want to start and get stuck in the middle because I do not have the correct fittings

Phil

[B72011]

OMG, is that 2nd pic a Toyota Cressida!?! Hahhahahha That was my 2nd car. Ironic, that when I got rid of it the tranny was going into neutral for no reason while driving. I added some trans "juice" to it so I could sell it for a few $$. YES..I did disclose the issue even though I was a broke a$$ highs skrewl kid. After I sold it, I got a dope little Datsun 510. Funny that about 3 months later while at the pick-a-part location I was looking for a smog pump to pass emissions (this is 1991 mind you)--what did I run across? The Cressida --DUNZO! Trans blew--game over. I cant believe someone put one of those back together!

[fly300kts]

Hey Phil, I'd been meaning to post this up, but never got around to it. I've been having bad TC lockup issues related to a failing TC and Valve body (the usual crap a number of people on here are dealing with nothing special) and I recently noticed they'd almost completely gone away after I replaced my failed T-Stat. I'm pretty positive the issues were, in part, caused by the failed T-Stat causing the tranny fluid temps to be lower than normal. My T-Stat was opening really early (~50*C, I tested it after I replaced it) and it was causing 10-15 minute warmup times coupled with periodice drops in temp while under load.

Anyway I replaced it last saturday (a little over a week ago) and the revving issue has almost completely subsided once the car is warm, and it appears to be diminished at lower temps (probably due to the warm coolant making its way to the Tranny faster because the coolant loop is operating properly).

Anyway I wanted to throw this out there as a counterpoint to "colder is better" as you said above. I may not be seeing the whole picture, but its definitely some food for thought.

Really good point Charles and I have two engineer at work calulating the cooler size I need as well as number of elements because you are right, too cold is not good either

Phil

[Charles.waite]

Really good point Charles and I have two engineer at work calulating the cooler size I need as well as number of elements because you are right, too cold is not good either

Phil

It might be interesting to put a thermostat inline or some sort of switchable bypass (connected to a dash mounted "Funk Button" of course ) where you could switch on the extra cooling when you're on a track, and switch it off for DD use. Of course that extra complexity might cause its own mess of problems, but its still a thought. I'm all for anything that can help increase the durability of this POS ZF tranny...

[clemsongt]

Phil

What would the benefit be of having a fan? The fan on the radiator for engine cooling is necessary because an idling car still makes heat. I would think a car idling doesn't generate much new heat in the tranny.

Just my thought

[fly300kts]

keep in mind that the FMIC inlet hose does obstruct alot the right scoop and in am not sure about how much air flow the radiator will see.
The fan could be a good help

Phil