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GM Transmissions

If you're in the market for a GM performance transmission, you're in the right place. We are dedicated to engineering and building the finest GM and Chevy Performance transmissions in the world. Our custom, hand-built transmissions can handle up to 1200 horse power and 1000 ft-lbs of torque and are built with the highest quality parts available.

Our high performance GM transmissions are built to the horsepower, torque, and rear gear ratio specs of the engine that it will be matched to. Unlike other performance transmissions builders, each individual transmission is built by one technician from start to finish. Before a transmission and torque converter leaves the facility, it is dyno tested for the equivalent of 100 miles to insure that it is in proper working condition.

Our lineup of Chevy performance and racing transmissions includes TH 350, TH 400, 700R4, 2004R, 4L60E, 4L65E, 4L70E, 4L80E, and 4L85E transmissions.

GM 700R4 Transmissions


The 700R4 is a four-speed automatic transmission that features a 30 percent overdrive in the fourth gear. The transmission was launched by GM, and is sometimes referred to as Hydramatic.

GM 700R4 transmissions were developed in 1982 as a replacement to the TH350. The main reason for the new design was to create an automatic transmission that was better on fuel economy. At the time, the 700R4 was used on trucks and rear-wheel drive vehicles such as the Chevrolet Blazer, Suburban, Corvette, Camaro, and Impala.

GM 700R4 Transmissions Are the Best Ever Produced

When the 700R4 was first released, it did have minor problems. Just five years later, the transmission had undergone several improvements and gained a more favorable reputation. In 1990, there was a name change to the 700R4 - the 4L60. It was essentially the same transmission, and in 1993, the 4L60 became electronically controlled instead of hydraulically controlled, which is where the name 4L60“E” comes from.

Even though the 700R4 transmission isn't made new these days, they are still considered to be some of the best ever produced. The improved fuel economy and gear ratio in first gear were the hottest selling points, providing drivers with good acceleration when stopped at a stop sign or stoplight. Also, the gear ratio was good for off-roading.

Benefits of the 700R4

Let’s look at a few facts about the 700R4, and why this may be the transmission you need for your hot rod.

  • Constructed of cast aluminum.
  • One of best overdrive transmissions.
  • Improved fuel economy.
  • Lower first gear ratio.
  • 30 percent overdrive.
  • 23.4 inches long; 155 pounds in weight.
  • Holds 11 quarts of trans fluid.

Custom Building a 700R4 With Innovative Technology

By choosing Gearstar to build a custom 700R4 for your needs, we will discuss some of the ways to make the trans work for you. This transmission is easily overheated because it is used in heavy-duty pickup trucks, as well as cars that are driven hard such as the Corvette or Camaro. Overheating is one of the main causes of transmission failure, and we don’t want this to happen to you.

If you plan on taking your car out with the 700R4, we may recommend a cooler that can be installed with the transmission. Even if you purchase a car with an old 700R4, the trans can be rebuilt with the latest upgrades to make it stronger and more durable.

Gearstar builds GM 700R4 transmissions by hand, only using premium products and one technician from start to finish.

GM 200 4R Transmissions


GM 200 4R transmissions definitely haven't gotten very much attention, however, don’t be discouraged by what these automatic trans can do in terms of performance. It’s nearly as strong as a 700R4, and can bolt into most Chevy’s without needing much modification. The 200 4R was introduced in 1980 to be used in the Chevy Corvette and Buick Grand National, until it was phased out in 1990.

Today, many vehicles still use the 200 4R transmission to give older cars an overdrive gear and more horsepower.

Features of GM 200 4R Transmissions

If you are considering putting a 200 4R transmission into your older vehicle, here are a few things you should know.

  • Improved Performance. Because it's an overdrive transmission, you can significantly improve performance in your vehicle. Take your car to the next level by upgrading your current TH350 or TH400.
  • Reduced Fuel Consumption. Overdrive transmissions make better use of fuel because the car’s engine speed decreases when using overdrive gearing. In addition to having improved fuel efficiency, there is less wear and tear on the vehicle.
  • Easy Installation. Another great feature s that it has easy installation and is surprisingly affordable. Capable of handling around 250-400 HP, and is the same length as Powerglide and TH350 transmissions.

200 4R: Easy Installation & Great Pricing

GM 200 4R transmissions are becoming harder and harder to find, but they remain a great replacement for an older two-speed Powerglide or a three-speed Turbo Hydra-Matic. The reason for this is because you don’t have to make major adjustments. Plus, the fourth gear lets the engine rotate at a lower RPM, reducing fuel consumption and wear and tear on the drivetrain. You can also change the larger rear axle ratios without affecting streetability.

Gearstar builds high performance automatic transmissions, and we highly recommend the 200 4R because of its straightforward installation and reasonable price tag. Because this transmission is an analog model, it doesn’t rely on a computer to tell it what to do like its “E” siblings. This is part of the reason why the price tag is smaller than other transmissions.

Contact Gearstar to have one of our expert technicians cutom build you an analog 200 4R transmission with reliable overdrive. You won’t regret it!

GM 4L60E Transmissions


4L60E refers to a series of automatic transmissions from GM. They are designed for longitudinal engine configurations, and include 4 forward gears and 1 reverse gear. GM 4L60E transmissions are rated up to 450 horsepower and 425 ft/lb torque, and can be custom built by Gearstar. We take great pride in our superior parts, attention to detail, and seasoned technicians. Only one person will build your 4L60E transmission - this is how perfection is achieved.

GM 4L60E Transmissions Are Some of the Best on the Market

The 4L60E is an automatic shift, four-speed overdrive transmission that has the reputation of being one of the best automatic transmissions ever made. Before the 4L60E was produced, there was another trans called the Turbo 700R4. This transmission was introduced in 1982, and the 4L60E transmission is a branch off this model. The “E” stands for the “E”lectronically shift controlled version.

When talking about GM 4L60E transmissions, there is the “early” version and the “late” version. The early version is from 1982-1989, while the late model is from 1996-2010. You can easily identify the later version of the 4L60E transmission based on its removeable bellhousing. Another determining factor is the six-bolt hex rear output.

The strength of the 4L60E is very impressive, and can be used in both trucks and cars. In fact, the 4L60E can be found in just about every GM rear-wheel drive such as the Sonoma, Taho, Safari, Astro, Yukon, Firebird, Camaro, and Corvette. While there are some concerns over the automatic transmission, the 4L60E is a solid product that continues to be strengthened and improved.

Advantages of the 4L60E

If you are considering the 4L60E, there are many benefits to think about, including (but not limited to):

  • Strength
  • Durability
  • Broad usability
  • Great for Jeeps
  • Modular design
  • New versions coming out
  • Impressive power

In short, the 4L60E is an excellent transmission that continues to be improved. It’s one of the most popular automatic transmissions in America, and there are still millions of them in use. Gearstar builds high performance transmissions that are handbuilt in our shop. Each transmission is built to your exact specifications using the best parts possible.

If you are interested in having an 4L60E transmission built for your truck or car, contact Gearstar today.

GM 4L65E Transmissions


The 4L65E, among others, was designed to replace the TH350. It’s a solid automatic transmission that is similar to the 4L60E, only with far more strength and power. GM 4L65E transmissions were designed to handle more torque, but has an identical looking case to its predecessor. However, the 4L65E is not compatible with the 4L60E because it uses a different torque converter and input shaft. If you plan on upgrading to the 4L65E transmission, you will need a converter.

How the 4L65E Transmission Has Evolved

The 4L65E was born because structural improvements needed to be made off older transmissions, such as the 4L60E. The 4L65E trasmission is stronger, has better performance, a hardened sun shell and input shaft, and a five-pinion rear planetary. Hot rodders appreciate having more pinion gears because the load is spread out, and the transmission can handle more torque. Additionally, the 4L65E features a deeper pan for more fluid and a 3-4 clutch.

If you are in the market for a new automatic transmission, you’re definitely doing yourself a favor by going with the 4L65E. Keep in mind that the older 60E is not compatible with the 65E, so you will need a converter. With the custom built transmissions from Gearstar, this is an easy issue to work around.

The only complaint that some drivers have had about the 4L65E is the jump from first to second gear. Some feel that the leap is too big. Yet for every person who doesn’t like the big jump, others love it. It’s all about preference, we suppose. There are some mods available to help with this wide ratio, but in actuality, there’s not much that can be done.

Custom Built GM 4L65E Transmissions

The areas where four-speed automatics shine is their strength, abundance, and opportunities for upgrade. Whether you’re interested in upgrading your current 4L60E transmission or are starting from scratch, Gearstar is happy to help! We custom build high performance automatic GM 4L65E transmissions using American made parts. When you place your order, only one highly qualified technician will work on your transmission, ensuring that everything is given the appropriate attention.

GM 4L70E Transmissions


Like most AODs at the time, GM 4L70E transmissions were designed with lightened materials to support better fuel efficiency, 4 speeds, and electronically-controlled shifting. However, like any series of stock transmissions, the 4L70E also came with its fair share of faults and limitations.

The final iteration in a line of 4-speed automatic transmissions beginning with the 700R4, the 4L70E is often compared to its nearly identical predecessor, the 4L60E. While some might contend that the differences are negligible at best, Gearstar contends that if you really know what you’re doing, then the potential of the 4L70E transmission outstrips its cousins.

We’ve worked hard and toiled long to offer reworked and optimized GM 4L70E transmissions, designed for modern performance – gutted and rebuilt to show you just how much you can get out of a quality GM transmission with some aftermarket parts, elbow grease, and the minds of our best and brightest builders here at Gearstar.

4L70E vs. 4L60E

From the outside, there is virtually no difference between GM 4L60E transmissions and later iterations of the 700R4, including both the 4L70E and 4L80E. In fact, they’re all stamp coded "4L60E". These stamps act as a code, tangible to easily identify a transmission. That’s where the differences start to clear up.

For the most part, the 4L70E easily replaces the 4L60E, but turning an old 4L60E into a 4L70E isn’t feasible – while they look incredibly similar, they’re completely different beasts on the inside.

To cut to the chase, the 4L70E is a stronger transmission. It’s made of sterner stuff, and comes with an input shaft speed sensor. Other major changes (in more depth) include an internal mode switch (IMS), replacing the neutral safety switch on older 4L60Es, a completely different valve body (with a different control solenoid), internal wiring that is completely different from the 4L60E, and a relocated transmission fluid temperature sensor (TFT).

When looking for a specific transmission in stock GM vehicles, it’s possible to tell the two apart without opening them up in just about two ways. First, the harness connector. The 4L70E typically has a black or neon blue harness connector. If that isn’t a reliable bet, then check the service parts identification tag on a GM vehicle. There should be an M70 on the tag if the vehicle’s stock transmission is a 4L70E. Otherwise, on its own, there’s no way to tell from external appearances alone.

GM 4L70E Transmissions Custom-Built With (More) Toughness

Installing a 4L70E transmission isn’t a plug-and-play job; you need the right power-train control module to communicate with the transmission, and in some cases, you may have to re-pin your wiring harness. Otherwise, chances are you can bolt a 4L70E transmission into most cars that don’t have a problem with the 4L60E.

Gearstar's GM 4L70E transmissions are custom-built to withstand some serious stress, through intensive modification. We build our 4L70Es with a 300mm input shaft and heavy-duty input drum, a steel five-pinion planet for added durability, a larger carbon fiber overdrive band for greater grip and reduced heat, and a super heavy-duty center shell that’ll help let the transmission last on the racetrack.

That’s not all, of course. Our transmissions also come with an updated boost valve, pressure regulator valve, new shift, EPC, PWM and 3/2 solenoids, an all-new electronic speed sensor, new stator and vanes, new pump assembly, hardened output shaft, an extra-capacity heavy-duty aluminum pan, a 30,000 GVW cooler and more.

Being an electronically-controlled automatic overdrive transmission, the 4L70E let's you calibrate shift timing, torque converter lock-up and more - which makes transmission far more versatile than older, throttle valve cable GM 4L60s. You’ll need either a laptop to calibrate your transmission, or get one of countless aftermarket alternatives.

At the end of the day, if you’re looking for a solid GM automatic transmission in the 650 HP and ft/lbs torque range, with overdrive and electronic calibration, then the 4L70E is an excellent choice. If you’re working on something closer to 450 HP, then we highly recommend the 4L65E.

On its own, straight out of the factory, there’s nothing particularly remarkable about the 4L70E. But in our hands here at Gearstar, we’ll quickly turn it into a contender for modern-day performance.

A High-Quality Investment in High-Performance

The 4L70E is a workhorse transmission, offering greater reliability and a great deal more power. If you’re looking for a transmission capable of working up and beyond the realm of about 450 HP and 425 ft/lbs of torque, and below 650 HP and 650 ft/lbs of torque, then upgrading to a 4L70E transmission is a great option.

On its own, you’re looking at a quality electronically-controlled automatic transmission – but with our expertise, the 4L70E quickly becomes a transmission capable of maintaining friction and minimizing slippage under highly demanding conditions.

Of course, what it can do for you depends entirely on what you need it to do, and what we can work with. A 4L70E can handle stress, but the build will be different for a customer looking for a custom gearbox for drag racing, versus someone who needs a workhorse to help in their towing business. No matter what you need, we put our heart into each project, and work on our transmissions as though they were being prepped for our very own personal rides.

Gearstar is staffed by only the best of the best: guys with decades of experience, and a real passion for heavy duty performance. We’re not making mass-produced, factory-made transmissions for the average family van. Our products are custom-built, race-tested and made to last.

Each and every transmission we build is dyno tested with a converter for the equivalent of 100 miles. We have five builders here at Gearstar giving their full attention to each order – every single customer who comes to us with a request for a transmission will not leave disappointed.If you’re ordering from us, you’re getting sheer quality.

GM 4L80E Transmissions


Horsepower is everything these days. The more horsepower a vehicle has, the better performance you will see from the engine. The problem with adding more horsepower is that it places additional pressure on the rest of the driveline. Fortunately, GM fans have multiple options when it comes to automatic transmissions.

GM 4L80E transmissions are often overlooked, yet is a top-rated leading option. This four-speed overdrive trans works with just about any power level and engine combination. It is based largely on the TH400 in strength and parts. The difference is the added overdrive gear, advanced electronic controls and a lock-up torque converter.

The Evolution of GM 4L80E Transmissions

GM 4L80E transmissions were first introduced in 1991. They were placed in GM trucks, such as the Sierra, Silverado, Suburban, and the Hummer H1. There were some minor issues with the automatic transmissions, but improvements have been made over the years.

For one, the newer boxes are more attractive and all models can be made to fit performance applications. This is one of the reasons why 4L80E transmissions find their way into luxury vehicles such as Bentleys, Jaguars, Rolls Royces, and Aston Martins.

Of course, we can’t forget that GM 4L80E transmissions can also be found in less appealing vehicles such as motorhomes and school buses!

4L80E vs. TH400

As stated before, the 4L80E is similar to the TH400. It has a 25 percent overdrive and is 4 inches longer than the TH400, but the trans mount is moved rearward by an inch-and-a-half. Also, the 4L80E is roughly 50 pounds heavier compared to the TH400 because of the electronic control.

Speaking of, the need for electronic control is a concern surrounding this transmission. The 4L80E transmission requires a controller, but some drivers appreciate that they can easily reprogram and adjust the display to their liking. Shift points, shift pressures, torque converter lockup, and overdrive can all be controlled by the user, offering endless possibilities and full control.

Today, GM 4L80E transmissions keep its die-cast aluminum frame and is mostly compatible with Chevrolet style GM engines. The high performance automatic transmission is widely recognized for its reliability and power.

If you’re looking to swap in a 4L80E transmission, Gearstar is happy to build a custom transmission that fits your needs!

GM 4L85E Transmissions


4L85E transmissions are a series of automatic trans that were introduced by GM. The 4L85E is exceptionally strong and versatile and can be used for off-road racing, drag racing or custom street driving. In other words, GM 4L85E transmissions mean serious business. If this is what you want for your vehicle, you’ve come to the right place. Gearstar will build you the most reliable and high-performing trans possible.

4L85E Is an Off-Roader's Best Friend

What makes this transmission a great upgrade? First, it’s from the GM 4L80E transmissions family, which is known for being strong. The trans can handle 460 lb-ft of torque, which is slightly higher than what the 4L80E can handle. It’s also based off the original TH400 three-speed transmission, which was heavy-duty in itself. You can find GM 4L85E transmissions in a number of vehicles, including the Chevrolet Avalanche, GMC Savana, Chevy Suburban, and GMC Yukon.

As you can see, the 4L85E transmission is ideal for larger vehicles. One of the biggest issues with large vehicles like Suburbans and Yukons is that they end up carrying a lot of weight because of the number of people they hold and the adequate space for luggage. These full-sized SUVs are also used for off-roading. It’s not uncommon to see them in snow, desert terrain or country roads.

Off-roading is hard on transmissions, especially with the buildup of heat. That’s why vehicles that are being used for heavy duty transporting or off-roading should be equipped with a transmission like the 4L85E. This transmission should operate at the max temperature. Every 20 degrees over that you go, you run the risk of cutting your transmission’s lifespan short.

Improving GM 4L85E Transmissions for Off-Roading

Gearstar builds custom GM 4L85E transmissions to your exact specifications. If you use your SUV for off-roading, let us know and there's a few things we can do. For example, we can add a transmission cooler with its own electric fan or a large cooler that is installed in an area with good airflow.

We can also talk about improving the 4L85E with a shift improver kit. The benefits to this include modifications for the transmission's internal line pressure, more physical control of your automatic transmission and a decrease in the time it takes for the clutch and bands to engage. This reduces wear and heat while off-roading.

If your interest has sparked, contact Gearstar today to discuss how we can start building your customized 4L85E transmission.