How Much Is A New Transmission For A GMC Sierra? [Answered]

It is not uncommon for the transmission in a GMC Sierra to last well over 150,000 miles, but what if something happens? How much is a new transmission for a GMC Sierra?

With proper maintenance and by not putting unnecessary stress on your transmission, your GMC Sierra should have zero transmission issues until late in the life of the vehicle. That being said, vehicles can be unpredictable. Even if you are not constantly towing or hauling and you are driving with care, a GMC Sierra could require a new transmission at any point. 

How Much Is A New Transmission For A GMC Sierra?

A new transmission on a GMC Sierra, no matter the year, can range anywhere from $2,000 to $4,000, not including labor. The labor costs associated with removing an old transmission and replacing it with a new one can add an additional $500 to $1,200 in overall cost. 

The bottom line is that no matter what type of vehicle you drive if you have to do a full transmission replacement or rebuild, it is going to be expensive. The transmission is one of the key components of any vehicle and it is a complicated piece of machinery with many moving parts. That is why if you own a GMC Sierra or any other type of vehicle, you should take care of your transmission. 

You should make sure you are keeping up with the appropriate routine maintenance as well as make sure you are not putting too much stress on your transmission. You can put unnecessary stress on your transmission by towing boats, trailers, or campers that are over your truck’s towing capacity, using your truck as a snowplow, and by driving recklessly. 

Let us take a look at what a transmission is, how it works, as well as all the things you can do to help preserve your transmission and the bad habits that slowly destroy it. 

To gather price information on transmissions for the GMC Sierra as well as to identify some of the good habits a vehicle owner can do to help prolong the life of their transmission, we have surveyed numerous transmission specialists from all over the country. 

Not only have we gathered information about prices and the good habits, but we have also surveyed these experts to identify the bad habits the vehicle owners can do that lead to the slow destruction of their vehicle’s transmission. 

What is a transmission and what does it do?

On a basic level, a transmission is vital to move the power from the engine to the wheels of the vehicle. A transmission can either be automatic or manual. 

Whether the transmission is automatic or manual, the transmission is typically located on the chassis in the front of the vehicle and it enables the gear ratio between the drive wheels and engine to adjust as the vehicle accelerates and slows down. When the vehicle is at a full stop, the transmission disconnects the engine from the drive wheels to allow the engine to idle when the wheels are not moving. 

Manual transmission (stick shift)

The main features of a vehicle with a manual transmission include a clutch pedal, stick shift, flywheel, and pressure plate. A manual transmission consists of a set of gears as well as input and output shafts. When a driver engages and disengages the clutch, they then can select the proper gear that the engine should be in based on how fast they are going, if they are accelerating, or if they are slowing down. The clutch releases the pressure plate which then disengages the clutch from the engine allowing for the smooth transition between gears. 

When it comes to manual transmissions, there are a few different types of transmissions that are typically used. There is the dual-clutch, unsynchronized, synchronized/constant mesh, automated, preselector, and single-clutch transmission.  

Automatic transmissions

The main difference between a manual and automatic transmission is that the process that a driver does to drive a manual transmission is all done inside of an automatic transmission on its own. Automatic transmissions also do not use clutches. 

An automatic transmission instead uses a torque converter to change gears. 

How to properly maintain a transmission on a GMC Sierra

To avoid costly transmission repairs or avoid the need to rebuild or replace the transmission in your GMC Sierra, there you can do several things to help prolong the life of your transmission. Here are ten ways to properly maintain a transmission on a GMC Sierra.

1. Check your transmission fluids

As often as you check your oil, you should be checking your transmission fluid. Make sure the transmission is always at the proper level. If you are constantly filling your transmission fluid reservoir, you may have a leak. Also, if you notice the fluid is murky, dark, and/or smells rotten, then you may want to make a visit to your local transmission specialist shop. 

2. Use the correct type of transmission fluid

Check the owner’s manual to see what kind of transmission fluid you should be using. If you are unsure, you can always ask a transmission specialist. Avoid using any type of transmission fluid that is not specifically designed for your vehicle. 

3. Have the cooling system regularly serviced

Having a properly functioning cooling system in your vehicle is essential to prevent the engine from overheating. The cooling system is also responsible for cooling the transmission fluid before it is pumped through your vehicle’s gearbox. 

4. Have your transmission flushed when recommended

You should have your transmission professionally flushed every year to remove debris, sludge, and other impurities from the transmission system to prevent the formation of rust on your Sierra. You can either do this annually or you can consult your owner’s manual or your mechanic to see at what mileage milestones you should have a transmission flush performed. 

5. Do not change gears when the car is moving (automatic transmission)

One of the worst things you can do for your automatic transmission is change gears while your car is in motion. For example, switching to reverse as you are rolling forward, even slowly. This can put a serious strain on the transmission and even cause a transmission blowout, also known as a “dropped transmission”. 

6. Let the engine warm-up before driving

Allowing your car to warm up before driving allows for all the fluids of the vehicle, including the transmission fluid, to make a complete cycle and properly lubricate everything before you set the car into motion.

7. Do not drive with a spare tire more than necessary

Driving with miss-matched tire sizes can put a lot of strain on your vehicle’s transmission. 

8. Change the transmission filter when recommended (automatic transmission)

Vehicles with an automatic transmission may have a filter that needs to be changed periodically. Some newer models may not have a transmission filter, however, if your vehicle has one, make sure it is changed every time you have your transmission flushed. 

9. Never tow more than the towing capacity

The towing capacity that is set by the manufacturer is there for a reason. Do not tow more weight than the towing capacity of your vehicle at any time. Doing so can harm your transmission and damage your vehicle in multiple ways. 

10. Have the transmission inspected every year by a certified mechanic

Once a year you should have your transmission inspected by a certified transmission specialist. They will look for leaks and any cause of concern in the transmission fluid. 

Bad habits that destroy the transmission on a GMC Sierra

As there are actions you can take to properly maintain your transmission, there are also actions that can accelerate the erosion of your transmission. Here are a few bad habits that you may want to break if you are looking to get the most life out of the transmission in your GMC Sierra.

1. Slamming on the breaks

Slamming on your breaks in an emergency situation to avoid a collision is unavoidable. Any other time you should never slam on the brakes of your vehicle. 

2. Not using the parking brake

If you do not use the parking brake, your transmission needs to work to keep your vehicle in place. This is especially true if you are parked on a hillside. Without the parking brake, it is up to your transmission sitting in the park position to prevent the vehicle from rolling forward or backward. 

3. Accelerating too quickly

You may think it’s fun to stomp on the accelerator and maybe even spin the tires from an idle position, however, doing so puts a lot of stress on your transmission, tires, and many other vehicle components.

Avoid accelerating too quickly and instead opt for a smooth acceleration that allows the gears to switch calmly and methodically. 

4. Not keeping up on transmission routine maintenance

Having your transmission inspected every year and keeping up with scheduled maintenance like transmission flushes is vital to prolonging the life of your transmissions.

Skipping or delaying these inspections and flushes can cause the components of your transmission to create friction when in operation. It is this friction that can cause the parts to wear down which then can require major repairs that can be extremely expensive. 

5. Not checking transmission fluid

You always should be checking your transmission fluid to make sure it is at the proper level and that it isn’t discolored, sludgy, or smelly. A transmission fluid reservoir that always needs to be topped off could be a sign of a slow leak in your transmission. If you have a leaky transmission, it is better to attend to it sooner rather than later to prevent the need for a major repair. 

6. Not coming to a complete stop before changing gears

Never change gears with your automatic transmission when your vehicle is in motion. Make sure you have come to a complete stop before placing your vehicle in park, reverse, etc. Placing your vehicle in park before it has come to a complete stop could cause your transmission to blow out. 

7. Towing too much weight

Although the GMC Sierra is well-known for its towing power, you will want to be sure that you do not exceed the towing capacity of your truck for any reason. Doing so could do incredible harm to your transmission as well as cause other damage to your vehicle.

If you are unsure of the towing capacity for your GMC Sierra, you should consult the owner’s manual for your vehicle for details. 

Towing capacity is determined by the size of the engine and the model of the GMC Sierra you own. For example, here is a breakdown of towing capacities for the 2022 GMC Sierra 1500. 

Model	2WD or 4WD	Turbo 2.7	5.3L V8	6.2L V8	Turbo-Diesel 3.0L
Crew cab small bed	2WD	9,000 lbs	9,300 lbs		9,100 lbs
Crew cab small bed + NHT	2WD		11,100 lbs		13,100 lbs
Crew cab small bed	4WD	8,800 lbs	9,200 lbs	8,900 lbs	8,800 lbs
Crew cab small bed + NHT	4WD		10,800 lbs	13,000 lbs	12,900 lbs
Crew cab regular bed	4WD	8,800 lbs	9,100 lbs	8,900 lbs	8,800 lbs
Crew cab regular bed + NHT	4WD		10,800 lbs	13,000 lbs	12,800 lbs
Extended cab regular bed	2WD	9,100 lbs	9,400 lbs		9,300 lbs
Extended cab regular bed + NHT	2WD		11,200 lbs		13,200 lbs
Extended cab regular bed	4WD	8,900 lbs	9,200 lbs		9,000 lbs
Extended cab regular bed + NHT	4WD		10,900 lbs		13,000 lbs
Standard cab regular bed	2WD	9,000 lbs
Standard cab regular bed	4WD	8,800 lbs
Standard cab extended bed	2WD	9,400 lbs	9,800 lbs
Standard cab extended bed	4WD	9,100 lbs	9,500 lbs

Again, these tow capacity weights expressed above in pounds is the absolute maximum amount of weight that the GMC Sierra can tow based on the engine type and model. Towing in excess can cause great stress on your transmission.