The forgotten device. Everyone knows that they need to put oil in the crankcase, coolant in the radiator, power steering fluid in the power steering reservoir, and water in the window washer container. But many people forget about the transmission. It needs fluid from time to time as well but is often not thought of.
The amount of transmission fluid you will need will depend on the type of change you are doing. A transmission fluid pan drain takes only 4 to 5 quarts while a complete change of fluid can take up to 14 quarts. The key will be to use the right transmission fluid.
To learn more about this transmission and the fluid it needs, just continue to read our article. It has that information and more. While they are still around, this transmission was only in production for 15 years, from 1991 to 2006.
If you are just doing a simple drain and fill with the standard fluid pan, then you can expect to use only 4 to 5 quarts of transmission fluid. That works out to about a gallon to just over one gallon of fluid.
But some of the owners of these transmissions have put or got the deeper pan. If you are one of those owners, then you can expect to add more fluid than that standard amount. If you are adding extra, do it slowly so you do not overfill the pan.
When you go to buy your new transmission fluid, you do not have to get the most modern version or the most expensive one. This is a simple, tough, old GM transmission and cheaper transmission fluids will not bother it.
The only thing you have to do is make sure it is the right type, which we will discuss later.
With the torque converter in play, you are looking to need 14 quarts of fluid to make your transmission operate as it should. That works out to 3 1/2 gallons which means you will have some fluid left over if you only buy the gallon size.
Then if you are using a deeper transmission fluid pan, you can expect to use up that extra fluid in no time. When you are adding the fluid, use the 14 quarts first and then check the level.
If it is low, add about a 1/2 quart at a time until you get the transmission up to the right fluid level. You really do not want to overfill the transmission as that will work against you, not help you in performance.
One chart shows a transmission with the stock pan holding between 10 and 12 quarts of transmission fluid. That seems to be a bit on the low side so you should check with your owner’s manual, or your dealer to get the right amount to use.
While you are doing that, with the torque converter, you are usually using 14 quarts of fluid with the stock pan. Subtract 9 to 10 quarts and you will get to the amount of transmission fluid in your transmission outside of the torque converter.
The converter holds a lot of fluid as it is a fluid-driven device and it needs more fluid to stay lubricated properly. Usually, unless you leave the pan off and have the transmission drain overnight, you won’t put more than 4 to 5 quarts of fluid in your transmission.
As you know, automakers and transmission makers are always working to upgrade the transmissions as well as the fluid. These days the go-to transmission fluid is Dexron VI.
The good part about these upgrades is that they are generally backward compatible. That means that if you want to use a better type of fluid, you can.
However, this is an older GM transmission and the old standard Dexron III is still good to use in this transmission model. Since the 4L80E is said to be one of the best transmissions ever made, going with the cheaper fluid is not going to hurt it.
You should be able to get Dexron III just about anywhere transmission fluid is sold but if you can’t, go with the Dexron VI. It will work and keep your transmission in top shape.
You can also use Mecron V transmission fluid if the others are not available.
You can buy Dexron III in different sizes depending on your need at the time. This fluid is for Automatic transmissions only and should not be used for any other application. It is not a rubber lubricant.
The viscosity for this fluid is 10w SAE 20 with an ISO viscosity grade of 32 and 46. The SSU viscosity grade is 150@100 degrees F & 220@100 degrees F. These figures go for either mineral or synthetic transmission fluid.
The mineral-based fluid is more affordable while the synthetic-based option lasts longer and endures a wider range of temperatures. The synthetic option is compatible with the mineral-based option.
Dexron III is REACH compliant and REACH stands for- REACH (Registration, Evaluation, Authorization, and Restriction of Chemicals).
Since it comes from the era where Dexron III started out in, then that would be the best transmission fluid to use in this transmission. However, a close second would be Dexron VI.
Its backward compatibility makes it an ideal transmission fluid to use in the 4L80E. The brand won’t matter although the lesser to not known brands probably have a lower quality than the better known ones.
It is perfectly fine to go with the Walmart brand if you feel that it is not harming your transmission. Just make sure it says Dexron III or VI on the label. But watch the other no-name brands they probably cut some corners in quality.
One recommendation would be to change your transmission fluid every 30,000 miles depending on use. If you do not use your vehicle that often, then it is okay to let the interval go a bit longer. But if you do a lot of towing and hauling, then more frequent transmission fluid change is needed.
This would include your transmission filter. That part number is GM 24236933 or ATP B-239. What tells you that you need to change the fluid is the color and the smell. If the color of the fluid is dark brown or brownish or black looking and smells burnt, then you need to change the fluid.
That interval should be the same whether you use Dexron III or VI. The fluid may last longer but this is an older transmission and needs proper care. You can check your manual or a transmission expert to see if your model can go longer in between changes.
Here are the steps to take to make sure you get an accurate reading:
- Drive around to warm up the trans
- Park on a level surface and leave the engine running
- Go through each gear selection and end in park
- Pop hood
- Pull the dipstick and wipe clean
- Put the dipstick back in
- Pull the dipstick back out and inspect the fluid level on it
- Put the dipstick back in if the level is good
** information comes from this discussion forum- https://www.dieselplace.com/threads/checking-fluid-level-on-4L80E.397006/
There is one danger that is shared by almost all transmission models, the 4L80E included. That is heat. The hotter your transmission runs the fewer miles it will last.
The ideal temperature range for the 4L80E transmission is between 180 and 200 degrees F. If you can keep your transmission between that range of numbers then you stand a good chance of having your transmission last over 100,000 miles. Most likely, you will see 80,000 to 90,000 miles.
Anything hotter will reduce the lifespan of the 4L80E as 225 degrees F lowers the lifespan to about 50,000 miles. 275 degrees F takes the lifespan down to about 15,000 miles and 300 degrees F lowers it to just over 2000 miles.
There are ways to lower the temperatures and keep them low. One way is to install a transmission cooler. Another way would be to swap out the standard pan and install a deeper pan so you have more fluid.
Keeping the fluid clean will also help so make those regular transmission fluid changes to protect your forgotten device.
Transmission maintenance and fluid change are as important as maintaining your engine and changing the other fluids in your vehicle on a regular basis. Proper maintenance will help protect your transmission and keep it working for many years.
With the 4L80E transmission, you can use Dexron III or VI and still have the right fluid inside. These older GM transmissions were built to last and they always do a great job when taken care of.