Derale 13011 Fluid Control Thermostat Kit,Silver

Works great. Paired with a mishimoto transmission cooler on my 2017 4Runner. Keeps the temps right around 160-170. I didn’t use the black fittings it came with just got 4 brass ones off here for $5.

Thermostat looks good and is affordable. Helps warm up my transmission with large cooler. Other reviewers were right about the supplied fittings. I installed them on one side of the thermostat with AN adapters on the other side. The supplied fittings leaked immediately while the AN adapters did not. Otherwise, thermostat functions well.

Installed this on a 2002 Tundra 4wd (with the existing OEM Tow Package Radiator) after seeing how the transmission fluid never rose higher than 135° on cold winter days after substantial driving. So, put this thermostatic valve in place which took some Hand Mojo to make it work in place and inline with the existing OEM Hoses. Fabbed up a custom bracket and made it happen like it was installed at the Toy Factory. The fittings are ALUMINUM (black) and not plastic like others stated. I used Toyota FIPG 103 Sealant on the threads and made sure to almost bottom them out. Also used Toyota spring clamps instead of the snake clamps as they are best. The winter transmission fluid temps now read about PLUS 15° higher than before in similar winter weather conditions. Another benefit is that the Derale Unit acts as a secondary fluid cooler in summer as the hot fluid passes through the Opened Valve Unit into the OEM Cooler and then back through the other side of the Unit heading towards the transmission. Its a dual benefit Unit. Winter fluid now is now 145-150° vs 125-130°. Summer stays under 180° when towing. Don’t be like others and put a huge transmission cooler on your 1st Gen Tundra because in winter you’ll over cool your fluid. Don’t go bigger than the OEM Factory Cooler as its not needed. This Derale Unit is just the right thing for those couple of cold months where fluid needs WARMING and is used in conjunction with your transmission cooler radiator. Secondary benefit is its a Cooler in summer. Yew!!! 1/8/22 Update: Valve working nicely! Second winter with this set up. Transmission Temps are staying in the optimal range. Warming faster and staying warmer in winter. Summer temps as cool as before.

It doesn’t work. It didn’t reroot the cool fluid, it let all the fluid pass uninterrupted regardless of temperature. Glad I tested it before installing it. Definitely will be returning this piece of junk.

Very pleased with the Derale 13011 thermostat and mounting bracket (bracket ordered separately). I purchased a used 2001 Chevy 2500HD 6.0L a few years back and my high trans temp - towing, outside temps at 110*, in stop/go traffic, my trans temp never exceeded 215*. I wanted to drop this a few degrees so mid summer I installed a tru-cool 40k transmission cooler and all summer long I never saw the trans exceed 165*. Fast forward till now, outdoor temps are in the 50's/60's and my trans temp doesn't reach 100* (Tru-Cool doing its job). I installed the Derale Thermostat and now my trans runs between 150*-160* (around town, towing, outside temps hitting mid 80's, stop/go traffic). I'm a happy camper.

Keeps my tranny temps in check and below 200*. Only thing is when you order it with the fittings, the fittings are NOT brass as it shows in the picture, they are aluminum.

I have been running this unit for a week now in 30-50F deg weather. It keeps the trans between 140F and 160F vs. 100F - 110F without the thermostat. So its an improvement but I would have liked to see it closer to its rated 180f deg temp rating. Part of this units issue is that it allows a claimed 10% fluid flow through the trans cooler regardless of trans temp to prevent air pockets and cavitation. I understand this is needed but if it was 5% vs. the 10% I think it would do a better job at controlling the temps. Too cold of trans temps is almost as bad as too hot of trans temps. I would probably buy again unless a better unit was made and proven to out perform this unit.

I have an older truck with an automatic transmission that just will not get up to temp in the winter with my short commute to work. It's a 2001 GMC 2500HD, with factory auxiliary cooler in the front, and there is just no chance the transmission could get up to a decent operating temp in 15 minutes driving in winter. This seems like it will be a good solution. I have had the thermostat installed for about a week now and even though it isn't winter at the moment, still seeing some cool weather and the transmission is heating up real quickly, just as I wanted. The thermostat block itself is a nice piece, the instructions are pretty good yet simple. The only major issue I had was with the aluminum barb fittings. This was probably user error, I had used a very good thread sealant on the threads when putting it together, but the sealant is old and should have been mixed better before use, so the fittings leaked. I definitely got the fittings tight enough because it stretched the threads on them, when I took it apart and checked them again. I ended up buying some heavy duty brass barbs from local NAPA which went together just fine. The only other oddity for this kit is the mounting holes on the thermostat. They are very close together and on the end of the block. Derale sells a mounting kit separately but it's not very cheap and my own solution was probably more heavy duty anyway (definitely cheaper). You can look at the pictures for some ideas on how to install this thing. I also did a writeup about installing this on silveradosierra dot com