Nice site. You could just use the switch to turn on the stock fan as another option.

 

what peoples opinion is on having an electric fan on the transmission cooler?
I'm thinking of upgrading the stock one, adding an electric fan controlled by an inline temp switch

You could just use the switch to turn on the stock fan as another option.

If your pcm has been tuned, your primary fan should be on by 203F-212F, and your 2ndary fan should be on by 212F-217F, which would make upgrading GM's KD1 external ATF cooler with a fan unnecessary - unless your car works / plays harder than normal.
To be clear: adding a fan to your KD1 is not a bad idea.
A pcm tune first is a better idea and a better value, and may make adding a fan to the KD1 unnecessary.

I'll assume you've a reason why you want better ATF cooling than a pcm tune provides ...

Also, what would be the best location for the temp switch? I'm guessing on the oil line leaving the transmission, as close to the transmission as possible?

Having the switch closer to the oil cooler would make wiring easier.
Would the temp be accurate by the time it gets to the oil cooler assuming I bypass the radiator?

Can't answer these with my experiences.

What setpoint should the switch be? American Volt has different option from 140F and up.

Strongly suspect that the following chart applies to DexRon3.
"
176°F ... 100,000 Miles ... Ideal temp
194°F ... 50,000 Miles ... Maximum recommended sustained temp
212°F ... 25,000 Miles ... Pressure drops
230°F ... 12,500 Miles ... Varnishes Form
248°F ... 6,250 Miles ... Seals Harden
275°F ... 3,125 Miles ... Clutches Slip
293°F ... 1,562 Miles ... Oil forms carbon, seals and clutches burn

Over 293°F, measure in minutes instead of miles.
"
Depending on the where you get your temp measurement, how hard your 4L60E works, and whether or not you're using DexRon3 or DexRon6, my vote would be between 194F & 212F.

The OE ATF temp sensor in the YukonXL (1500) that I drove 100-200 miles a day for 7 years never exceeded 212F, even on summer days over 104F.
Obviously it used DexRon6; I do not know where the Yukon XL's ATF temp sensor is.

 

Ok, thanks.

No real reason except preservation. I just had the tranny rebuilt. It has a higher stall torque converter and I'm under the impression that creates heat in city driving. I figuered a fan is cheap insurance. This summer i'll monitor temperatures and see what I hit.

 

Also, what would be the best location for the temp switch? I'm guessing on the oil line leaving the transmission, as close to the transmission as posible?

Having the switch closer to the oil cooler would make wiring easier. Would the temp be acurate by the time it gets to the oil cooler assuming I bypass the radiator?

What setpoint should the switch be? American Volt has different option from 140 F and up.

Thanks.

Closest to leaving transmission would be best. By the oil cooler is fine. It's not going to cool off much.
I'd start with the 200deg on 185deg/off.

Those temps quoted come from the old days of old fluids. It's good if you're selling coolers Don't be afraid. Engine oils hit pretty high temps and their seals aren't failing.

Also, the PCM does not know the fluid temp so you're hoping it tracks. It doesn't always. I'd put a gauge in place of the switch first to see what temps you hit. Then pick a switch that doesn't always stay on.

Also, it's spelled Dexron if you're looking for something exact

 

Unless it's really warm in your part of Canada, keep the ATF radiator sidetank lines connected year round.
Those help warm the ATF to operating temp sooner.
In hot summers, the ATF radiator sidetank is no longer a cooler, and can be a liability for unusually hard-working transmissions.

3.73 helps quite a bit all by itself.
Any sensible 3.73 tune keeps the 4L60E in 3rd or 4th over about 19MpH, which also helps more.
In terms of the tune, how much time the TCC stays locked in 3rd & 4th is the only thing that could potentially be increased to keep the ATF even cooler. It might also help improve metro / urban MpG.
However, some people do not like the feel of a locked TCC under certain road speeds.
GM's OE tune would not lock the 4L60E's TCC under 37MpH in 3rd / 46MpH in 4th for V4Ps.
Without customized tuning, I'd suspect your TCC behaves similarly.

How much heat do YOU create in city driving? By which I mean:
how much time do you spend driving under 19MpH?
OR
how much time do you spend driving hard enough to stay in 2nd or 1st over 20MpH?

Unless you spend a lot of time driving hard for sport, or towing / hauling over 2000lb - which you'd've mentioned in the form you filled out for PCM Performance, right? - you probably don't NEED to put a fan on your KD1.

 

PeterDuerr, if you still want to add a fan to your KD1 anyway (may still be a good idea!):
pick a setpoint that would not activate the fan unless the DexRon6 exceeds at least 212F.
Maybe even higher than that, depending where that's measured.

Doubt your KD1 would need help, unless:
it's very hot out
you're driving harder than normal (for whatever reason) for more than a few minutes at a time.

 

DexRon6

Ok, got to ask again, why the persistent misspelling of things? It's not a preposition here.
I know we're not the NY Times, but we're not FB either...

 

Ok, thanks for the advice. Ill leave the radiator hooked up for now and monitor. June-Aug can be 100F +.

In town I can usually maintain 30MPH, so hopefully thats good enough air flow.

My PCM is in the mail. I mentioned the estimated stall from the manufacturer but I didn't request any changes to shift pressure ect.. i dont understand enough about that to start messing with it.

 

How do you monitor your ATF temps specifically?
H2Opump coolant temp and ATF temp do not usually correlate, and differ moreso as the powertrain works harder to please the driver.

Even on the transmission's hot side, ATF temps can vary depending on where the measurement is taken.

Bet your PCM arrives Mon or Tues.
If your post-tune shifts are gentle / soft, PCM Performance will firm them up a bit to protect your 4L60E, if you ask.

 

I was thinking infrared temp gun? Hope that comment doesn't get me kick out. Haha.

It has a transgo HD2 kit. I did include that detail on the tune order sheet. Failed to mention that here.

Its supposed to arrive on wednesday.

 

Don't see why it would?
Measure at a few different HOT spots between the 4L60E itself and the KD1 (pre-KD1, not post-KD1).
Have you considered a deeper ATF pan, and/or an ATF pan with cooling fins?
Obviously avoid the deeper pan if you've lowered your car or your roads are very schidty.

For now, you can just fab up anything that redirects more airflow at your KD1.
(Too bad an Olds Custom Cruiser front fascia is unlikely ...)

 

NOT trying to annoy you, or anyone else.
GUESSing 'dexron' is a portmanteau of two words, or two syllables from two different words.
If I learn it's something else, it'll affect how I spell it going forward.

1. If how I represent that guess in how I spell GM's branded ATF will mislead others to buy the wrong ATF, then I'll go back and edit those guesses so more people will buy the right ATF.
2. If it looks too facespooky (may very well never use that 'word'), I may also go back and edit them.

 

Do not bother with any additional cooling. For regular driving, the stock cooler setup is fine, and city temps won't hurt anything. If you're worried about heat, run Dexron6 or just swap out your DexMerc3 every two years (this is what I do). Done.

 

Get a scan tool and watch the trans temps on some hot days then decide.
That's what I did and found in my case additional trans cooling mods were not required.
Been to the Okanagan in the summer too

 

Sounds like you have a nice low-mileage car. Is the radiator original?

 

.

 

Yes, most likely original radiator. I just picked up this scan tool. From what I gather its the only one that reasonably priced. Under $1000. I had no idea about the in between stage (not obd1 not obd2 )
It just arrived and the PCM is in the mail, so not sure of all the features yet.

 

If you have a laptop, you could've bought
TunerCat's OBD1 LT1 Pro Kit
For $290 shipped to Canada.

The ISSF can stretch your Canadough a lot further than that thing.

Even if you're the only person within 200km who owns any LT1 car, and you are vehemently opposed to self tuning, I'd still send it back for a refund if at all possible if I were you.

 

I think your right, im pretty sure i can return this. Its unopened.
The tuner cat does seem more like what I want. Im not going to "tune" per say but I like to have all the features.

That being said, does it read tranny temp?

 

Too short answer:
Think DataCat (real-time analytic software that comes with the Pro kit) reads Torque Converter Clutch Fluid temp.

Longer answer:
The cheapest thing would be slightly more effort.
1. Download $EEhack FREE! It also reads TCC Fluid temp
(1a. you don't need TunerPro or FlashHack, but those are also FREE!)
2. Buy TunerCAT's cable for $125 shipped ($155 to also connect to Camaros & FireBirds)
3. you just saved more Canadough

 

Torque Converter Clutch Fluid temp,
Trans temp is oil in pan temp.

If you just wanted to deal with one place you could just get the TC obd1 cable and datacat for 135us plus the ride.
Later you could add the flash program if you wanted to play mail order or the actual program if you want to start doing stuff yourself.

My LT1 scanning stuff is ancient ( lt1 edit and Datamaster ) and not supported.
While I have not used Datacat , I have used a lot of TCs stuff and his support is second to none.

 

Torque Converter Clutch Fluid temp.
Trans temp is oil in pan temp.

Which is hotter? (asked the pessimist)

TunerCat's stuff is awesome, and so is he.
TunerPro FlashHack & $EEhack are 100% less, though.

 

Depends on what you are doing to the trans at the time.
My reply was to you saying that TC data software reads convertor fluid temperature.
The only temperature sensor in the trans reads oil temp it the pan.
So, that is the only reading you can get from software.
The switch , as you know , in the cooler line is on or off so all software will give is status.

 

My copy of DataMaster (superseded long ago by DataCat) mislabels ATF temp as TCC Fluid temp.

 

I am using a stand alone fan with the sensor at the incoming line for the small radiator. The unit is right behind the bumper and it looks like a dead air space. I picked up a small fan for a motorcycle on ebay. The sensor pushes through the radiator tubes. I have a 164 deg. sensor. There were 2 large triangular mounting flanges that I had to remove before installation.

 

Keep in mind that the transmission does not create internal heat like the engine does. If it doesn't get close to 100C / 212F occasionally, it won't boil off any moisture. Normal operating temps will still yield a 20 year / 150K service life for the seals. Clutches only cook when there is insufficient line pressure to properly clamp. That issue cannot be solved with a trans cooler (which is personally why I strongly recommend transmission PRESSURE and not temperature.)

 

I have sent my PCM in the mail but its not set to arrive till mid week. I may be able to email Alex at PCM Performance to change a few things.
If it's not a too complicated question to answer, What would you recomend he changes in the transmission programming?