---
product_id: 611226387
title: "Superior 6L80 6L90 8L90 Sure Cool System Upgrade STL010 with Bypass Gasket"
price: "฿4964"
currency: THB
in_stock: true
reviews_count: 8
url: https://www.desertcart.co.th/products/611226387-superior-6l80-6l90-8l90-sure-cool-system-upgrade-stl010-bypass
store_origin: TH
region: Thailand
---

# Immediate fluid level check, no warm-up needed Reduces operating temps by up to 20% Built-in safety bypass prevents overheating Superior 6L80 6L90 8L90 Sure Cool System Upgrade STL010 with Bypass Gasket

**Price:** ฿4964
**Availability:** ✅ In Stock

## Summary

> ❄️ Keep your transmission chill and your drive unstoppable!

## Quick Answers

- **What is this?** Superior 6L80 6L90 8L90 Sure Cool System Upgrade STL010 with Bypass Gasket
- **How much does it cost?** ฿4964 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.co.th](https://www.desertcart.co.th/products/611226387-superior-6l80-6l90-8l90-sure-cool-system-upgrade-stl010-bypass)

## Best For

- Customers looking for quality international products

## Why This Product

- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **DIY Friendly Upgrade:** Easy 10-30 minute install—perfect for the hands-on pro on the go.
- • **Instant Fluid Insight:** Check your transmission fluid level accurately without waiting for warm-up cycles.
- • **Maximize ATF Longevity:** Lower temps mean extended transmission fluid life and fewer replacements.
- • **Cooler Runs, Longer Life:** Slash transmission temps by up to 20% for peak performance under load.
- • **Overheat? Not on Our Watch:** Safety bypass gasket reduces risk of costly transmission failures.

## Overview

The Sure Cool System Upgrade STL010 with Bypass Gasket is a precision-engineered transmission cooler enhancement designed to reduce operating temperatures by up to 20%, provide immediate and accurate fluid level readings without warm-up, and prevent overheating with a built-in safety bypass. Ideal for heavy loads and towing, this easy-to-install upgrade extends transmission fluid life and protects your investment in demanding driving conditions.

## Description

Buy WIT WHATEVER IT TAKES TRANSMISSION PARTS, INC Superior 6L80 6L90 8L90 Sure Cool System Upgrade STL010 with Bypass Gasket: Transmissions & Parts - desertcart.com ✓ FREE DELIVERY possible on eligible purchases

Review: 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!
Review: it works - worked great. easy install and brought my temp down drastically

## Features

- Built in safety bypass Immediate cooler fill.
- Immediate accurate fluid level check without warm-up cycle
- Reduced average operating temperatures by as much as 20%
- Reduced risk of overheat while under load, Increased ATF life.
- Includes Bypass Gasket

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0CV6RDK5V |
| Best Sellers Rank | #8,979 in Automotive ( See Top 100 in Automotive ) #47 in Automotive Replacement Transmissions & Parts |
| Brand | WIT WHATEVER IT TAKES TRANSMISSION PARTS, INC |
| Customer Reviews | 4.8 4.8 out of 5 stars (412) |
| 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 |

## Images

![Superior 6L80 6L90 8L90 Sure Cool System Upgrade STL010 with Bypass Gasket - Image 1](https://m.media-amazon.com/images/I/61jMu20b8ZL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Easy and effective!
*by C***D on July 20, 2025*

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!

### ⭐⭐⭐⭐⭐ it works
*by J***N on February 9, 2026*

worked great. easy install and brought my temp down drastically

### ⭐⭐⭐⭐⭐ 2015 GMC Sierra 5.3l (6l80 transmission)
*by C***R on January 30, 2026*

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.

## Frequently Bought Together

- WIT WHATEVER IT TAKES TRANSMISSION PARTS, INC Superior 6L80 6L90 8L90 Sure Cool System Upgrade STL010 with Bypass Gasket
- atp automotive B-239 Automatic Transmission Filter Kit for GM Optional 6L80 Heavy-Duty 6-Speed Transmission
- ACDelco GM Original Equipment 10-9395 Dexron VI Automatic Transmission Fluid - 1 gal

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*Product available on Desertcart Thailand*
*Store origin: TH*
*Last updated: 2026-03-04*