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🛠️ Upgrade your ride’s heartbeat—cool smarter, drive stronger!
The WIT WHATEVER IT TAKES Superior Sure Cool System Upgrade STL010 is a precision-engineered transmission cooler upgrade for 6L80, 6L90, and 8L90 models. Featuring a built-in safety bypass gasket, it enables immediate cooler fill and fluid level checks without warm-up, reducing average operating temperatures by up to 20%. This upgrade significantly lowers the risk of overheating under heavy load, extending ATF life and transmission durability. Lightweight and compact (4x4x1 inches, 4.6 oz), it installs easily in under 30 minutes, backed by a 4.8-star rating from hundreds of satisfied users.





| ASIN | B0CV6RDK5V |
| Best Sellers Rank | #8,997 in Automotive ( See Top 100 in Automotive ) #44 in Automotive Replacement Transmissions & Parts |
| Brand | WIT WHATEVER IT TAKES TRANSMISSION PARTS, INC |
| Customer Reviews | 4.8 4.8 out of 5 stars (460) |
| Date First Available | February 7, 2024 |
| Item Weight | 4.6 ounces |
| Item model number | STL010 |
| Manufacturer | Superior |
| Manufacturer Part Number | STL010 |
| Model | COOLER FLOW BYPASS |
| Product Dimensions | 4 x 4 x 1 inches |
S**S
Excellent product.
Easy to install, works very well. Mtransmission stays much cooler and shifts better under heavy load.
D**R
A must need product if your transmission is getting hot
I received my product and installed it the next day. Very simple to install. Instructions are easy to follow and so simple. Great fit, great value for the money and no leakage at all. Once installed my temperatures dropped by 40 degrees. I was running at 205 degrees, I am not running between 150 and 167 degrees. This is amazing. I am not having any durability issues at the moment. I recommend this product to anyone who is having a transmission heating issues or overheating issues.
C**Y
Great product
Works great. Highly recommended. Easy to replace
C**R
2015 GMC Sierra 5.3l (6l80 transmission)
If you pull a trailer, have a constant load, live in a warmer climate, or just want your transmission to last longer, I recommend this device. Especially for the price. Very easy installation for the driveway DIYer. I installed on a 2015 GMC Sierra 5.3l with a 6l80 NEW transmission that I had to replace at ~84kmi. Normal temp on stock valve opens at 194*F. This modification keeps the temps well below that and circulates the fluid all times. One thing to note, the little bracket that holds the cooler lines to it is ONE WAY. It looks symmetrical at first glance but is very slightly offset. The holes will not line up if not the right way. I have driven across the country and it has kept temps below 160 while moving. I also have a constant weight as I am a full time overlander. I haven’t tested in the extreme summer temps yet but no matter what, it will keep the transmission running cooler.
C**D
Easy and effective!
Pulling a 6000# trailer with my 1500, tends to make the transmission fluid run hot, especially with a stock transmission cooler thermostat that doesn’t open until 194°. Was recommended this product to lower the temp and make my new transmission last for years. Watched several videos and people were saying it takes 10-30 minutes for this install. I’m currently in a cast, and considered it a challenge! It did take me closer to the 30 min mark, but was super easy to do, even 1 handed. Temps dropped 40-50° at highway speeds and 20-40° for city driving (in 94° summer heat). Will see how well it works this weekend while pulling our camper. Fantastic product, just wish I would have known about it years ago - could have saved my factory transmission and $5k to replace it!
L**S
Great product
Works great keeps my transmission at around 150-165
M**E
Works great on higher/older factory thermostat bypass
Do your research on your vehicle before buying. My 2016 had the 180-190 degree thermostat in it from the factory. So I went from running up to 190 after warm up and never coming back down to 120 on a 30 mile daily interstate trip in the morning. When I started hitting stoplights in town it went to 130, then would drop back to 128 once I was moving for a few blocks. In about 2017 the factory installed the 140 degree thermostat so if you already have that you won’t see the result I’m getting. I only gave 4 stars for two reasons. Although I bought the kit with the gasket it did not come with the 2 small o rings for the cooler lines so do not lose them when taking the block off. One of my o rings stayed in the block and the other on the line. The second reason is the instructions didn’t state whether or not to leave the bottom factory spring in or out of the block. I stopped there and went to good ole YouTube for clarification. You remove all the internal parts including the factory spring and install all the parts from the kit. Im looking forward to the same trip home in the heat today to see how low it runs. Update, 30 mile drive home on interstate the same day, 95 degrees outside, trans temp stayed at 140 degrees the whole way home. 50 degree drop in operating temperature. I wish I would have installed this a long time ago.
J**E
Follow the instructions on the check ball orientation.
Worked like a charm easy to install and keeps my transmission significantly cooler.
H**L
Good
Easy to install. Does what it says. Max running temp 71°C uphills with a heavy right foot. Previously 91°C
J**S
Gracias por tener estas refacciones vehiculares
Excelente producto ya se le instaló a mi camioneta y funciona de maravilla muchas gracias por tener este tipo de refacciones
A**A
Better than a transmission cooler in my opinion for normal use
Easy to install by yourself Transmission temperature used to be at 130 C in a 30 minute mountain pass in 20 C weather. Now its 100 C in the same mountain pass and 30 C weather. Also, transmission temperature will go back to 85 C after 20 minutes of normal driving.
C**V
A must buy
Excellent product. Did exactly what it was purchased for.
B**I
ممتاز
كما في الصورة
Trustpilot
3 days ago
2 weeks ago