I have an 08 XL 5.4L with the tranny cooler. In the cold Wisconsin winters, would it be beneficial to cover the tranny cooler to keep the tranny fluid from turning to jello to help improve gas mileage?

 

I wouldn't think you would need to cover, transmission fluid seems to have no trouble coming up to temperature and above. But I don't live in the frosty north.

 

How hot is your tranny fluid getting? Do you know what temperature it is?

 

It could help if you work the truck hard in very cold temps. The fluid can gel in the cooler. Covering it will reduce that tendency.

 

i have an aftermarket trans temp and its in the pan and just last week it finaly went over 100* i was idleing for 15 mins after driving the truck to 180* water temp. after 15 mins the trans temp was 140* i also have a rebuilt tranny with amsoil in it. i live in michigan and winter aint no hot time here. ill cover my cooler with somthing and let you know how it goes... you also gotta rember it goes into the radator out of the radator then into the trans cooler.... so maybe cover the lower driver side half of the radator too?

 

I know about the winters in Michigan. I've lived there my whole life, 20 of those years right next to you in Novi.

Covering the radiator isn't going to make much difference either way. Covering the trans cooler is worthwhile.

 

I have only had the truck a few months, so I haven't had the chance to get a tranny temp guage. Thanks for you help Mark.

 

Get a ScanGauge II.

 

Your truck has a thermostat installed in the cooler lines that you can see right beside the oil pan. When the fluid is still too cold to open that thermostat any, it still let's around 10% of the fluid flow through just to keep fluid moving instead of sitting stagnant on that cooler side of the system. Plus, this time of the year, the fluid going through the radiator tank is being warmed by the water instead of cooled. I say you're perfectly OK taking no action.

 

Thank you Galaxy. I wasn't aware that there was a thermostat on it.

 

If you look under your truck on the passenger side right beside the (engine) oil pan, you'll see a funny shaped block with four lines going into it. That's it! When fluid is cold, it still leaves the tranny as if it were headed to the cooler, but 90% of the fluid gets to this block and makes a u-turn straight back into the tranny. Then when the fluid warms up (I do not know the actual temp) that block opens up internally and let's all the fluid continue on it's journey to the cooler. It is also not either fully open or closed. It does modulate to maintain a desired temp.

My '02 doesn't have one and I installed a SD cooler on my truck so now I'm having cooling problems in winter. They're only $35 new from the dealer so I may put one on my truck next year. Great simple little mod. But since you '04 and up guys already have it, you're set!!

 

So galaxy, you are saying all '04+ with the tranny cooler, has a thermostat to control the tranny fluid?

 

When I was changing my tranny fluid, I wondered what that little block was. Thanks

 

I won't swear to it, but as far as I know, yes.

 

I have a livewire tuner with my trans temp on display.Reads it right from the pcm.I havent had any issues at all even at -10 the temp comes right up.