As you may know, the 4l60e & the 4l80e are really common transmissions in GM, Chevrolet cars and a lot of other American cars.

But what actually is the difference between the 4L60e vs the 4L80e transmission? Can you swap between them?

In this article, we will discuss everything about this and you will get the specifications for both transmissions and the differences between these.

Let’s start with the specifications!

4L60E vs 4L80E Specifications

Name 4l60E 4l80E
Type 4 Speed Automatic
Overdrive
4 Speed Automatic
Overdrive
Applications GM Cars - GMC, Chevy/Chevrolet, Buick GM Cars - GMC, Chevy/Chevrolet, Buick
Gears 3 + 1 Overdrive 30% 3 + 1 Overdrive 30%
Weight 150 lbs dry~ 236 lbs dry~
Lenght 23.5" 26.4"
Gear Ratios 1: 3.059
2: 1.625
3: 1.00
4: 0.696
R: 2.294
1: 2.482
2: 1.482
3: 1.00
4: 0.750
R: 2.077
Case Material Aluminum Aluminum
Fluid Capacity 11 Quarts 13.5 Quarts
Fluid Type DEXRON VI DEXRON VI
Max Torque 350nm +/- 450nm +/-
Image 4L60E 4L60E Transmission
Pan Gasket/Bolt Pattern 16 bolt

4L60E Gasket
17 bolt

4L80E Gasket
Name Before TH350
700R4
TH400

Differences between the 4L60E & 4L80E transmission

4L80E

Even if these transmissions look pretty much the same on the pictures, there are a lot of things that are different between these transmissions. Here are the most significant differences between these transmissions. Remember that these are the main differences and you can find other small differences if you carry out more in-depth research.

1. The size & weight

The biggest difference is probably the size & the weight between the 4L60E and the 4L80e transmission. The 4L80e is much larger and heavier than the 4L60E. The 4L60E has a weight of 150 lbs without fluid and a length of 23.5″, while the 4L80e has a weight of 236 lbs and a length of 26.4″. Just with these numbers, you can probably calculate that there is a big difference in size and weight between these transmissions.

2. Gear ratios

Another big difference between these transmissions that is important to think about if you are going to swap them, is the gear ratios. For example, on the first gear, the 4L60e has a gear ratio of 3.059:1 while the 4L80e has a gear ratio of 2.48:1. This is important to keep in mind if you are swapping between any of these transmissions. You can normally compensate for the new gear ratio with another rear axle differential, so this is not always a big problem, but it’s good to know about.

3. Pan & pan gasket

If you are looking under the transmission for the transmission fluid pan, you will realise that there is a big difference between the transmissions. This is a good way to identify if you have a 4L60e or a 4L80e transmission in your car. The 4L60e has a rectangular pan & gasket of 16 bolts and the 4L80e has a more oval-shaped transmission pan with 17 bolts. You can see the pictures of the gasket in the specification above.

4. Max torque

Due to the size of the transmissions, there is also a large difference between the durability of these transmissions when it comes to performance. This is mainly because of larger internals inside the transmissions. The 4l60e transmission can handle a max torque of around 350nm, while the 4l80e can handle 450nm~ or even more. These numbers can differ a lot and you will get a lot of different answers about how much these can handle. We have to remember that there is a big difference in the durability between a 30-year-old transmission and a new one. So the condition of the transmission is important to consider when you want to know the max torque.

6. Wiring harness, controller & sensors

There is a big difference when it comes to the electronics of these transmissions. The wiring harness and the transmission control unit are completely different and they are not compatible with each other. There are also differences when it comes to the sensors, mainly that the 4L80e has 2-speed sensors that are different than the sensor on the 4l60e. If you want to swap to one of these transmissions, remember to also purchase the control unit and the harness.

8. Price

Because the 4L60e is a lot more common than the 4L80e, there is also a big difference in the pricing of both used and new transmissions. This also applies to the parts because there are much easier and more available parts & whole transmissions of the 4L60e than the 4L80e. If you want to find parts for these, I  recommend you to check online. If you have a 4L60e, you can probably go to a junkyard and find parts for your transmission, depending on where you live.

However, you can also find both new and used transmissions and parts online; one of the places to check for these is on Amazon. Here are some of the examples of what you can find.


Similarities between these transmissions

If you are looking at the transmission, they actually look pretty much the same, depending on the year of the transmissions. One of the similarities between these transmissions is that both of them are electronically controlled. The bolt pattern for the transfer case is also the same so it will fit in a swap without problems.

One thing to consider is that the 4l60e was named th350 and 700r4 before in earlier models and the 4l80e was named th400.

4L60E to 4L80E Swap

4L60E To 4L80E Swap Kit

If you have checked the recent information in this article, you may have figured out already that swapping between these transmissions is not plug & play at all. There are a lot of differences in these transmissions and here are some of the things you have to consider if you are going to swap the 4L60e to a 4L80e transmission. Remember that some points can differ depending on the year and the car model of the transmission and the car you are swapping in.

Swapping a 4l60e transmission to a 4l80e transmission is not an easy job, but it’s totally do-able if you are willing to spend some time and money. Here are the things you have to consider:

Transmission tunnel

Because of the larger size of the 4L80e transmission, you may have to modify the transmission on the car that you are going to swap it to. Sometimes, the car models come with both 4L60e and 4l80e from the manufacturer and in these situations, you have to bear this in mind. However, sometimes you have to use a hammer and a welder to make it fit properly.

Wiring harness

There is a big difference when it comes to the wirings and sensors for the transmissions. You can do it yourself and repin and rewire the OEM wirings, but it’s pretty difficult and time-consuming and it’s not a job for a beginner. A much easier way to do it is to get a pre-made swap kit harness, which is not cheap but I can still recommend it because you will save a lot of time and headache. You can find the transmission wiring harness swap kit here from Amazon: 4L60e to 4L80e Transmission Plug and Play Adapter Harness LS SwapIr?t=Askamastermec 20&l=Am2&o=1&a=B076Qln4Xr

Dipstick

The dipstick is different on the 4l80e transmission and you have to consider this when doing your swap. If your car model came from a factory with the 4l80e, get a dipstick from a transmission that has been fitted in one of these cars. Otherwise, there are a lot of custom solutions that can be done or you can get a flexible dipstick like this one for 4l80e:
Lokar XTD-3518FM Transmission DipstickIr?t=Askamastermec 20&l=Am2&o=1&a=B005P6Qrzq

Driveshaft/propshaft

The 4l80e driveshaft is longer than the 4l60e and this has to be considered when doing your swap. However, the same thing applies here. If your car model came with the 4l80e transmission from the factory, get a driveshaft from one of these models if possible. If not, there are a lot of shops that can make the driveshaft shorter for you. You can also measure and check for a driveshaft on other models to see if you can find one with the same length.

Flex plate/torque converter

You have two alternatives on this one to make it work properly. You can either get a special adapter kit which normally includes a spacer and an input shaft to make it work with your converter. Alternatively, you can use the flex plate and the torque converter from the 4l80e transmission.

ECM

The engine control unit often has to get reflashed and reprogrammed for the 4l80e transmission to work properly. You can search the web or find a local dealer to do this job for you. There are also premade control units for this but it’s often pretty expensive. If you are making any modifications to the engine as well, it’s recommended to let a tuner do the transmission reprogramming at the same time as they are tuning the engine on the dyno.

Crossmember

The 4L80e transmission case is longer than the 4l60e transmission, so the cross member has to be modified. You can either purchase an already premade cross member or you can make one yourself with a welder and some skills. Remember that it’s important to get the transmission perfectly lined up straight. There are a lot of differences between which car you are going to convert and how much you have to rebuild the cross member.

If the car that you are swapping the 4l80e transmission into came with that transmission from the manufacturer, you can get one of these crossmembers and install it on your car for a plug and play situation.

Conclusion

Overall, these transmissions are completely different even if they look almost the same. In summary, the 4l80e is larger and can take more power than the 4l60e. If you are going to swap your transmission, try to get as many parts as possible from the 4l80e transmission that you are purchasing, like the torque converter, flex plate, dipstick etc.

I think I have covered the most important parts when it comes to the difference and the swapping between the 4l60e and the 4l80e transmissions. If I have missed something or if you have any other questions, you are welcome to ask your questions below and I will answer them as soon as possible. I hope you enjoyed the guide!