greenbomer
New member
I resonantly put a trans cooler on by passing the radiator. I'm wondering what to use for a cover in cooled weather. Need some idea's from some fellow snow bunny's.
Trans cooler cover
- Thread starter greenbomer
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JayRolla
New member
Im confused? You want to cover the cooler because its cold out?
gamefreakgc
Elite Member
It's my understanding that they have a cold fluid bypass, meaning it does not go into the fins and instead acts more like a return line back to the transmission.
That being said, I do remember reading something on the instructions that for very cold climates the cooler was not recommended since it kept the fluid cold longer than normal.
That being said, I do remember reading something on the instructions that for very cold climates the cooler was not recommended since it kept the fluid cold longer than normal.
Black798
New member
I have a B&M 20268 cooler on mine. Its been around 20 in the mornings lately and Im seeing it take close to 45 minutes of driving to get my pan temp up to the 120-140 range it usually runs at. I think I will probably end up just cutting a piece of plastic that can be removed in the summer but will cover either half or the whole cooler during the winter and see if that helps my temps not take so long to get to where they should be.
mtbtim
Elite Member
Your cooler probably has a thermal bypass, but since you bypassed the radiator, you lost the benefit the stock cooler in the radiator offers by bringing up the temperature of the ATF quicker since the cooler is immersed in the warm engine coolant.
Cooler manufacturers never recommend people bypass their stock cooler but they especially warn people to not bypass if they live in cold climates.
This is the scenario I think some people overlook when they bypass to avoid the trans cooler failure (aka pink milkshake). Most know operating very high trans temps is bad, but operating too low isn't the greatest either. ATF has an optimum operating temp of around 175 degrees. Running below 150 degrees for long periods can allow condensation to build up in the transmission which supposedly isn't great for your transmission. Also, when you're running low ATF temps, the fluid viscosity increases and you'll get reduced lubrication.
I'm not a transmission expert or automotive engineer but I've done lots of reading on this subject. Instead of looking for a cover for your cooler, why don't you just switch to running your cooler in-series with the stock cooler? The pink milkshake can happen, but I think it's chances of happening are much much slimmer than it's made out to be on this forum.
Cooler manufacturers never recommend people bypass their stock cooler but they especially warn people to not bypass if they live in cold climates.
This is the scenario I think some people overlook when they bypass to avoid the trans cooler failure (aka pink milkshake). Most know operating very high trans temps is bad, but operating too low isn't the greatest either. ATF has an optimum operating temp of around 175 degrees. Running below 150 degrees for long periods can allow condensation to build up in the transmission which supposedly isn't great for your transmission. Also, when you're running low ATF temps, the fluid viscosity increases and you'll get reduced lubrication.
I'm not a transmission expert or automotive engineer but I've done lots of reading on this subject. Instead of looking for a cover for your cooler, why don't you just switch to running your cooler in-series with the stock cooler? The pink milkshake can happen, but I think it's chances of happening are much much slimmer than it's made out to be on this forum.
tx_shooter
New member
This is the best option in my research and experience. I replaced the stock radiator with a new radiator; best $100 I have spent in a while. Then I added a big B&M cooler. The smaller coolers do have the built in temp bypass but the larger coolers do not. I added in a temp bypass switch that bypasses the B&M cooler until the temp reaches 165* where it starts to open up. It is fully open at 180* allowing the transmission to take full advantage of the stock cooler and the B&M cooler.
mtbtim
Elite Member
What does a temp bypass switch look like? Sounds like a good way to go but I guess I'd worry about it failing. Any idea how reliable they are?
I'd love to see some pics of what your install looks like.
greenbomer
New member
Thanks Black798 morning down her are in the mid 30s, I need to warm up this trans to.
tx_shooter
New member
I will get some pics uploaded when I get home tonight. It has been in place for over a year now without any issues. My transmission warms up like normal and then stays cool; even behind a supercharger.
I also wouldn't mind seeing pics of that.
Wouldn't it have just been easier though to get a cooler with the temperature bypass built in?
[MENTION=120071]mtbtim[/MENTION], remember I had told you I'm in-series as well but can't really get to or above 150 on tranny temp unless I drive for a while. To add to that, Denver hasn't really hit our cold temps yet, winter is still on the way and the daytimes will be under 20 sometimes.
My point of saying that is the tranny fluid going to the radiator with the coolant being nearby there doesn't help as much as I'd like. It's not the aux cooler's fault though, I have a Tru-Cool 4544 and that should have the LPD or low pressure drop which is the thermal bypass when it's not hot enough to be cooled yet. So even if I didn't have an aux cooler, I'd in theory be seeing the same temps below 150 for X amount of time/miles with the stock radiator.
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Here is my input with trans coolers.
The Cruiser 100 I recently acquired has a huge OEM trans cooler in-line with the radiator (fluid goes first to the radiator and then to the trans cooler).
On a hot summer day with AC at hi etc., the return line from the external trans cooler to the transmission is barely hot, I don't even notice it as warm. The line coming out from the radiator going into the trans cooler is hot to touch. So, this means basically room temp fluid is flowing into the trans. This is what the factory made it to be.
The Cruiser 100 I recently acquired has a huge OEM trans cooler in-line with the radiator (fluid goes first to the radiator and then to the trans cooler).
On a hot summer day with AC at hi etc., the return line from the external trans cooler to the transmission is barely hot, I don't even notice it as warm. The line coming out from the radiator going into the trans cooler is hot to touch. So, this means basically room temp fluid is flowing into the trans. This is what the factory made it to be.
mtbtim
Elite Member
I have seen the same with my rig. Before I even installed the cooler, I saw trans temps in the 130's driving down the freeway. When you get onto surface streets, the temps will be warmer since you don't have all that air blowing through the front of your rig.
I know I've spouted all this information about optimum trans fluid temps and being under 150 for long periods isn't great for the transmission based off what I've read. How bad it is for the life of your transmission, I have no clue. It's obvious to me that people who live in very cold climates are going to see much lower trans fluids temps than someone who lives in the California Bay Area like me. But, knowing you live in an area that has cold winters, why would you want to exacerbate the trans temp issue by bypassing the stock cooler. I have no clue how much effect the stock cooler immersed in the hot engine coolant has on the trans temps but it has to be doing something. If you understand heat transfer principles, the hot engine coolant surrounding the trans cooler is transferring heat to the ATF running through the cooler via conduction. Again, how much will it raise the ATF temps for us, I have no clue. Also, companies that sell these coolers warn people about bypassing if they live in cold climates and I figure they're not just saying that for the hell of it.
I guess what I'm trying to say is we have to do the best with what we know. The trans cooler in the radiator is doing something to help raise the trans fluid temps to an optimum operating temperature quicker and I guess something is better than nothing when you compare it to a bypassed system.
I'm with you.
I was bypassed and converted to in-series.
Denver isn't the coldest of climates. I would bet Montana is colder where OP lives. I know for sure Canada gets way colder.
