23 replies to this topic

[98silvz71]

My parents have an 07 Avalanche without an external transmission cooler. According to the DIC it runs at 183 degrees when fully warmed up. I personally don't like it that warm and especially now since they are looking for a camper or a toy hauler to make into a sleeper/toy hauler. I put a Hayden Medium Duty cooler on my 98 for about 60 bucks and was pretty happy with it. However I am not sure how much it cooled it down because I didn't have a temp gauge on the tranny. So my question is, go for the OEM cooler with the hard lines and mounting hardware or go for aftermarket?

[WaterBoyz]

Go with an after market PLATE style.

But then, 183* is about right since the trans fluid runs thru the rad.

[98silvz71]

Go with an after market PLATE style.

But then, 183* is about right since the trans fluid runs thru the rad.

Right I know it runs through the radiator. I just think that 183* is too high for my likings. I'd like it to be about the 140 range like my Allison is running. I was looking at the Hayden Medium Duty Plate style cooler ( I can't remember part number) like my I used before but with 60 bucks either for aftermarket or for OEM I was just wondering which would be better? #1 for cooling/efficiency and #2 for ease of installation.

Edited by 98silvz71, 24 May 2008 - 11:56 AM.

[yukondan]

Aftermarket tranny collers are usually rated by the intended GCWR (Gross Combined Weight Rating) and the Heat rejection (BTU/HR). A stacked plate design is more effecent than a traditional design and usually a smaller foot print. Don't be fooled by size.

I have had excellent results with Tekonsha Defender SR coolers. They are stacked plate and Self Regulating (SR) with 2 by-pass plates within the cooler core to sense transmission fluid viscosity. If the fluid cold (thick) additional cooling is not needed and the fluid will primarily through the by-pass plates. When the fluid reaches operating temperature (thin) it will cycle freely through all the available cooling plates. This allows the fluid to maintain optimal transmission performance.

A over cooled transmission fluid will not allow the transmission to work in it's designed temperature range preventing torque converter from locking up and seals from working in their designed temperature range.

You also need to NOT by-pass the built-in cooler in the radiator. The heat the fluid receives from the radiator allows the fluid to reach operating temperature faster.

Make sure that the cooler and additional hoses / tubing meet the minimum inside diameter (ID) to maximize flow and reduce strain on the transmission pump (failure due to restriction). 183° F. is optimal operating temperature. I would be concerned if the temperature reaches 210° F. for any length of time (longer than mometary cresting of a mountain grade pulling a load).

Towing my Travel trailer, I normally see 185 - 190° f. pulling in the summer months in 95° + F. temperature and never goes past 200° F. pulling 6 - 8% mountain grades in the Carolinas / Tenn.

[98silvz71]

Aftermarket tranny collers are usually rated by the intended GCWR (Gross Combined Weight Rating) and the Heat rejection (BTU/HR). A stacked plate design is more effecent than a traditional design and usually a smaller foot print. Don't be fooled by size.

I have had excellent results with Tekonsha Defender SR coolers. They are stacked plate and Self Regulating (SR) with 2 by-pass plates within the cooler core to sense transmission fluid viscosity. If the fluid cold (thick) additional cooling is not needed and the fluid will primarily through the by-pass plates. When the fluid reaches operating temperature (thin) it will cycle freely through all the available cooling plates. This allows the fluid to maintain optimal transmission performance.

A over cooled transmission fluid will not allow the transmission to work in it's designed temperature range preventing torque converter from locking up and seals from working in their designed temperature range.

You also need to NOT by-pass the built-in cooler in the radiator. The heat the fluid receives from the radiator allows the fluid to reach operating temperature faster.

Make sure that the cooler and additional hoses / tubing meet the minimum inside diameter (ID) to maximize flow and reduce strain on the transmission pump (failure due to restriction). 183° F. is optimal operating temperature. I would be concerned if the temperature reaches 210° F. for any length of time (longer than mometary cresting of a mountain grade pulling a load).

Towing my Travel trailer, I normally see 185 - 190° f. pulling in the summer months in 95° + F. temperature and never goes past 200° F. pulling 6 - 8% mountain grades in the Carolinas / Tenn.

From what I read 120 is the minimum range that you want it to be at and 180 is the maximum, so 150 would be right in the middle.

[WaterBoyz]

found this site for coolers
http://www.transmissioncoolers.us/

Craigslist ... not sure of the type
http://skagit.craigs.../678382419.html


Of course, the absolute best is a remote stacked plate with temperature bypass and with its own fan.
Can be mounted underneath near the trans.
No trans BTU in the rad.
Best of both worlds.

my 3¢(USD)

[FRANKD3TANK]

My tranny hits 225, is this too high?

[nbscancuck]

Pulling 5000lbs trailer into a 20 to 30 mph headwind, my temp never broke 190. That included pulling out of three LONG, steep river valleys. It was mostly in the 175-180 range. My truck does have the trailer towing package, which includes a tranny cooler. It was about 70 degrees

[bob002500]

my 08 z71 reg cab, runs around 155 to 160 in the hot texas sun down the highway

[WaterBoyz]

My tranny hits 225, is this too high?

Yes.

[C & A s Dad]

Cam, you have already received some excellent advice here. An aftermarket unit is fine just make sure it is a stacked plate cooler and not a tube and fin. I see you live in MO. You winter temps will drive what size cooler you buy because in very cole weather you can overcool a trans to a point where the fluid will remain too thick. I live in the deep south and run a Hayden SP unit that is 11 x 11 x 3/4" and it keeps my temps nice and cool pulling my 6500lb camper. It was 91 yesterday and I saw max temps of 165 while towing. In really cold climates, this cooler would be too large.

I would suggest you look into what YukonDan used or you could go with their 11 x 9.5 x 3/4 and you would be fine. Hayden is our (CARQUEST) Supplier and our # on this unit is 77422 while the larger unit is a 77423. I would also suggest their 77018 universal kit which will help you mount the unit on the "A" bracket just in front of the A/C Condensor. I am not a fan of the straps through the radiator method.

You are doing the right thing. If they are going to be towing a camper of any size, the truck has to have a cooler. IMO, no truck should ever come off the assy line without an aux trans cooler.

And Frankd, 225 is too high in my opinion. I would not be frantic if it hit that for a few minutes but if it is running anywhere near that for any length of time, you are asking for trouble.

Edited by C & A s Dad, 27 May 2008 - 08:41 AM.

[slimjim2525]

My tranny hits 225, is this too high?

Yes.

[alaskaLTZ]

Cam, you have already received some excellent advice here. An aftermarket unit is fine just make sure it is a stacked plate cooler and not a tube and fin. I see you live in MO. You winter temps will drive what size cooler you buy because in very cole weather you can overcool a trans to a point where the fluid will remain too thick. I live in the deep south and run a Hayden SP unit that is 11 x 11 x 3/4" and it keeps my temps nice and cool pulling my 6500lb camper. It was 91 yesterday and I saw max temps of 165 while towing. In really cold climates, this cooler would be too large.

I would suggest you look into what YukonDan used or you could go with their 11 x 9.5 x 3/4 and you would be fine. Hayden is our (CARQUEST) Supplier and our # on this unit is 77422 while the larger unit is a 77423. I would also suggest their 77018 universal kit which will help you mount the unit on the "A" bracket just in front of the A/C Condensor. I am not a fan of the straps through the radiator method.

You are doing the right thing. If they are going to be towing a camper of any size, the truck has to have a cooler. IMO, no truck should ever come off the assy line without an aux trans cooler.

And Frankd, 225 is too high in my opinion. I would not be frantic if it hit that for a few minutes but if it is running anywhere near that for any length of time, you are asking for trouble.

I am thinking of upgrading mine, I was hitting 196* this weekend in the mountians, dragging 7500. I may just be too used to my Allison which never got over 170* if I really tried to get it warm!
I am curious of the surface area difference between the stocker and the one you mention here. Any thoughts?

[98silvz71]

Cam, you have already received some excellent advice here. An aftermarket unit is fine just make sure it is a stacked plate cooler and not a tube and fin. I see you live in MO. You winter temps will drive what size cooler you buy because in very cole weather you can overcool a trans to a point where the fluid will remain too thick. I live in the deep south and run a Hayden SP unit that is 11 x 11 x 3/4" and it keeps my temps nice and cool pulling my 6500lb camper. It was 91 yesterday and I saw max temps of 165 while towing. In really cold climates, this cooler would be too large.

I would suggest you look into what YukonDan used or you could go with their 11 x 9.5 x 3/4 and you would be fine. Hayden is our (CARQUEST) Supplier and our # on this unit is 77422 while the larger unit is a 77423. I would also suggest their 77018 universal kit which will help you mount the unit on the "A" bracket just in front of the A/C Condensor. I am not a fan of the straps through the radiator method.

You are doing the right thing. If they are going to be towing a camper of any size, the truck has to have a cooler. IMO, no truck should ever come off the assy line without an aux trans cooler.

And Frankd, 225 is too high in my opinion. I would not be frantic if it hit that for a few minutes but if it is running anywhere near that for any length of time, you are asking for trouble.

You suggested the exact cooler I was looking at. Its the same one I used on my 98 Silvy 350. The Hayden Part number 678. I don't have a Carquest close to me so I don't really know what the 77018 is because Hayden doesn't list that one. They have the fitting adapter kit and I thought maybe I could make my own mounting on the "A" frame. How about extra hose because I know on my 98 I didn't have enough so I turned it sideways.

[C & A s Dad]

Alaskaltz, your OE unit is approx 5" x 11" x 3/4" so you can compare this to the ones I mentioned. If you did move up to the 11 x 11 x 3/4 unit you would likely have to block some of it off in the winter concidering you live in a really cold climate. I would guess you would see a 25 to 30 degree drop in temps over your OE aux cooler. BTW, the OE Aux cooler is exactly the same stacked plate design as the Hayden coolers I am talking about.

Cam, the 77018 is a universal install kit that Hayden does supply to us and they do offer it in the Hayden brand, I just do not have access to their #s. It contains some metal straps that can be bent and shaped to accomodate your mount, some bolts and nuts and some rubber lined clamps used to route your hose. You could certainly make some brackets but the kit is pretty inexpensive.

If you send me PM me an e mail address, I have about 8 good shots of my cooler installed with the grille removed. I will be happy to e mail the pics.