New Trans Cooler

smattei14 · April 27, 2009

Hey...I just replaced my OEM trans cooler (9.5 x 11 x 3/4 stack plate, from Car Quest), along with new trans fluids (AMSOIL). He dropped the pan and got out 7 of the 10 quarts...(not bad).

Here in the Northeast we had our 1st tease of summer and the temps (outside) where around 90-93.

I have a 2006 Yukon Denali with the e fans (not the biggest fan of them).

Since I have changed the fluids and the trans cooler (about a 2 weeks ago). When the temps were in the 40/50/60's i never got above 150 when moving, and 190 when sitting for a long time.

I was stuck in traffic today (temp outside were around 90) and the trans temp got up to around 210, but the funny thing is when i got moving it did not drop that much (down to about 190 or 200). In my mind, this is way to hot, I didn't even have my 26 foot boat hooked up.

Not sure what to do now...I would not like my trans temp to go above 190/200 period (traffic or not)

Open for ideas....

Thanks in advance.

REV353 · April 27, 2009

I have heard of some cars/trucks having a check valve in the tranny line or system. What I was told is that it's there to get the tranny up to running temp faster and then open like a thermostat. This is for us ppl that start our vehicles up, get the oil pressure up and then leave. I have heard of them sticking and cooking the tranny. Just a thought, the Amsoil should of dropped your temp and maid it shift easier, it did on my 2500hd.

C & A s Dad · April 27, 2009

Your temps sound odd. Oil to air coolers are all about surface to air contact. You have plenty of surface with the cooler you installed so it has to be an issue with not enough air.

I towed my 6500lb camper this weekend and the outside temp was 85 degrees, which is about 10 degrees less than our typical summer heat. I also had the worst head wind I had ever towed in to. My trans temps remained in the mid 150s while driving. Once I entered the state park I had about a 2 mile drive at 15 mph and then entered the campground which slowed me even further. Once I got backed in to our site, my trans temp was 163. I let it idle for about 3 mins while I got out and checked to see if I had the camper sitting where I wanted it and when I got back in the truck, it was at 158.

I am afraid your E fans are simply not coming on soon enough or when they do they are simply not moving enough air to keep your trans temps under 200.

Most people will tell you 210 is not dangerous and it really is not, especially with synthetic fluid. However, I am in agreement with you, I want my max temp to be under 200 if at all possible.

I will be anxious to see any suggestions you recieve from others. One idea is a high capacity finned alluminum trans pan like this. PMC I know you likely do not want to do that but it may be an option.

txab · April 27, 2009

+1 on checking the fan operation.

MarkD · April 27, 2009

Forgive the hijack...

I changed my fluid and filter. It was 93 here friday. Temp stayed around 160 on interstate. Idled around town (Chick-fil-a drive thru) and the temp got up to 190-200 (no load or trailer). On the way back home (30 min 70 mph interstate) the temps didn't drop below 190.

Is this normal for a stock setup?

smattei14 · April 27, 2009

Your temps sound odd. Oil to air coolers are all about surface to air contact. You have plenty of surface with the cooler you installed so it has to be an issue with not enough air.

I towed my 6500lb camper this weekend and the outside temp was 85 degrees, which is about 10 degrees less than our typical summer heat. I also had the worst head wind I had ever towed in to. My trans temps remained in the mid 150s while driving. Once I entered the state park I had about a 2 mile drive at 15 mph and then entered the campground which slowed me even further. Once I got backed in to our site, my trans temp was 163. I let it idle for about 3 mins while I got out and checked to see if I had the camper sitting where I wanted it and when I got back in the truck, it was at 158.

I am afraid your E fans are simply not coming on soon enough or when they do they are simply not moving enough air to keep your trans temps under 200.

Most people will tell you 210 is not dangerous and it really is not, especially with synthetic fluid. However, I am in agreement with you, I want my max temp to be under 200 if at all possible.

I will be anxious to see any suggestions you recieve from others. One idea is a high capacity finned alluminum trans pan like this. PMC I know you likely do not want to do that but it may be an option.

Funny you brought this up. I knew you would respond to a Trans Temp/Cooler post here...lol

But I was looking at my Engine temp...it got up to around 215/220 then dropped down to 195 when the fans runs. I was watching to see if the trans temp would drop during the period when the fans where running and it didn't drop that much (210 to 200).

Is there any type of fan just for the Trans cooler that I can buy? How would that affect me in the winter since I do live in PA and i take ski trips up north to Vermont alot during the winter (temps are in the teens to neg single digs during the winter).

I would not mind the e fans at all if they were to keep my trans temp down to no higher then 190/200. I do like that it provides better gas MPG's and all...but on the same time it does not help out my trans.

Open for ideas on this one...

Rat4go · April 27, 2009

Your temps sound odd. Oil to air coolers are all about surface to air contact. You have plenty of surface with the cooler you installed so it has to be an issue with not enough air.

I towed my 6500lb camper this weekend and the outside temp was 85 degrees, which is about 10 degrees less than our typical summer heat. I also had the worst head wind I had ever towed in to. My trans temps remained in the mid 150s while driving. Once I entered the state park I had about a 2 mile drive at 15 mph and then entered the campground which slowed me even further. Once I got backed in to our site, my trans temp was 163. I let it idle for about 3 mins while I got out and checked to see if I had the camper sitting where I wanted it and when I got back in the truck, it was at 158.

I am afraid your E fans are simply not coming on soon enough or when they do they are simply not moving enough air to keep your trans temps under 200.

Most people will tell you 210 is not dangerous and it really is not, especially with synthetic fluid. However, I am in agreement with you, I want my max temp to be under 200 if at all possible.

I will be anxious to see any suggestions you recieve from others. One idea is a high capacity finned alluminum trans pan like this. PMC I know you likely do not want to do that but it may be an option.

Funny you brought this up. I knew you would respond to a Trans Temp/Cooler post here...lol

But I was looking at my Engine temp...it got up to around 215/220 then dropped down to 195 when the fans runs. I was watching to see if the trans temp would drop during the period when the fans where running and it didn't drop that much (210 to 200).

Is there any type of fan just for the Trans cooler that I can buy? How would that affect me in the winter since I do live in PA and i take ski trips up north to Vermont alot during the winter (temps are in the teens to neg single digs during the winter).

I would not mind the e fans at all if they were to keep my trans temp down to no higher then 190/200. I do like that it provides better gas MPG's and all...but on the same time it does not help out my trans.

Open for ideas on this one...

There is no check-valve thing in your 4-speed trans as rev353 suggested might be the case.

I'd think the trans will take quite a while to cool once it's warm....there's 10+ qts of fluid and 200 lbs of transmission metal back there, and you're trying to cool it all off with coolers that are much smaller than the radiator that cools the engine. I'd bet that running your fans in the stop-n-go would have kept the coolant cooler, and also kept the trans cooler as in those conditions, I'd bet the hot coolant was heating your ATF and the aux cooler was doing nothing due to lack of airflow. As silly as it sounds, next time, turn the AC on. This will get the fans turned on and I'd bet that the coolant would stay lower....you get the idea.

A dedicated fan for the aux cooler might help pull heat out quicker, but only if you're not adding heat at the radiator trans cooler due to hot coolant.

C & A s Dad · April 27, 2009

"Funny you brought this up. I knew you would respond to a Trans Temp/Cooler post here...lol

But I was looking at my Engine temp...it got up to around 215/220 then dropped down to 195 when the fans runs. I was watching to see if the trans temp would drop during the period when the fans where running and it didn't drop that much (210 to 200).

Is there any type of fan just for the Trans cooler that I can buy? How would that affect me in the winter since I do live in PA and i take ski trips up north to Vermont alot during the winter (temps are in the teens to neg single digs during the winter).

I would not mind the e fans at all if they were to keep my trans temp down to no higher then 190/200. I do like that it provides better gas MPG's and all...but on the same time it does not help out my trans.

Open for ideas on this one..."

Me respond to a trans temp question or comment. ? Never

I have no idea of the CFM rating on the E fans used on GM trucks but it would seem they provide plenty of flow accross the radiator but simply do not pull as much air accross the trans cooler as mechanical fans. As you know, the trans cooler is mounted severa inches in front of the AC Condensor which is a couple of inches in front of the radiator. My guess is there is simply not enough pull with the e fans to get good flow over the trans cooler.

The exact cooler you bought is avail with a fan mounted to it (CQ # 77659) Because you already have the cooler, you could add a fan to it. Hayden offers a thin line fan in a 10" (77500), 12" (77501), 14" (77502) etc. I had seriously considered using one of these units but after contacting Hayden, I discovered they were primarily desgined for mounting in remote locations. He told me that the fan would restrict airflow when it was not running and they did not recommend it for mounting in the grille. However, this was before GM began using E fans. With your situation, you could possibly use one of these small fans and mount it to the front of your cooler. You could use either an adjustable e fan controller like the 77528 or the 77530 or you could control it with a manual switch.

I realize your trans temps are not dangerous and there are millions of trucks on the road with e fans, but what you are experiencing, is why I say e fans have their place, on a car. IMO trucks, which are expected to tow and haul heavy loads should be equiped with mechanical fans.

Let me know what you think about adding a fan to the front of your cooler.

PS All of the #s I provided are CQ #s. You can visit Hayden's website if you want their #s.

smattei14 · April 27, 2009

Awesome Info..thanks!

I am very int. in adding a trans cooler fan...about how much do they run?

I would prob like to have the manual fan so during the winter I could turn it off since I live in the NE, and i could trun it on when i tow and turn it off when I see the temps are good.

My only worry...why would you mount it in the front of the trans cooler? I thought you would mount it from behind..so it would pull air through?

I guess a good way to put it is that I am really on the edge for doing this project...because like you said..my temps are not that bad since I am using ASOIL fluid but at the same time...I have a mind set that if I am around 190 or 200...its too hot in my book...e fans are for cars...yes...you are correct.

The real question is...why can't the e fans I have now pull enough air flow for the trans cooler? I mean..if it can cool off the radiator (which is behind everything, so the air would have to be pulled through the AC and all), it should cool off the trans...

Ohhhh the joy of trucks...

C & A s Dad · April 27, 2009

Depending on the size you needed, the fan would run around 85.00 to 95.00. You could then use any type manual switch you needed. If you go this route, be sure and use the wire gauge they suggest or even larger.

The blades can be reversed on these fans so they can be used to push or pull. If you have room to mount it behind the cooler, that would seem best to me.

To answer your question about the e fans. My guess is they simply are not moving the same CFM as the mechanical fans. If the trans cooler was mounted directly to the radiator, there would likely be enough flow. However, this is not possible because you have an A/C condensor in front of the radiator .

You could possibly mount it directly to the A/C condensor with one of the cable tie mounting kits but I would not suggest this and I still do not think you would get enough air.

smattei14 · April 27, 2009

Depending on the size you needed, the fan would run around 85.00 to 95.00. You could then use any type manual switch you needed. If you go this route, be sure and use the wire gauge they suggest or even larger.

The blades can be reversed on these fans so they can be used to push or pull. If you have room to mount it behind the cooler, that would seem best to me.

To answer your question about the e fans. My guess is they simply are not moving the same CFM as the mechanical fans. If the trans cooler was mounted directly to the radiator, there would likely be enough flow. However, this is not possible because you have an A/C condensor in front of the radiator .

You could possibly mount it directly to the A/C condensor with one of the cable tie mounting kits but I would not suggest this and I still do not think you would get enough air.

sounds good..great info..thanks...

before I do this project I want to get more info and do some research...I don't want to rip off the front if it will only improve my temp by a little...