Beware: Common Problems of the 4T80E Automatic Transmission

Posted by on Thursday, January 17th, 2013

The 4T80E is a four speed transmission made by General Motors for use in cars with the engine mounted transversely. It also incorporates a transaxle to allow its use in front wheel drive vehicles. The 4T80E is a heavy duty transmission designed to be used in cars weighing up to 8000 lbs. It was introduces in 1993 and phased out of production after the 2005 model year. It was used in big, heavy, V8 powered vehicles such as the Cadillac Deville, Eldorado, Seville and DTS as well as in the Oldsmobile Aurora, the Pontiac Bonneville and the Buick Lucerne.

4t80 automatic transmission


Although this is a heavy duty transmission, it still has its share of problems. Here are a few things you should look for the next time you’re dealing with a 4T80E equipped car that needs to be serviced.

All sorts of problems can result from bad shift solenoids. The vehicle might not shift, it might shift too hard or it just might slip a little or a lot. It can happen in any of the forward gears. Use an ohm meter to check the resistance of the wires in the solenoid. The resistance for a properly functioning solenoid should be between 20 – 30 ohms. If you get a different reading or none at all replace the solenoid. Solenoids are nothing more than a fancy electric magnet. The winding inside the solenoid create a magnetic field when voltage is applied. This causes a valve to move which either opens or closes a hydraulic port.

Location of solenoids on the 4T80E transmission



Transmission leaks. All types of leaks are common with this transmission, especially those that sit for long periods of time without being driven. What happens is that the seals and gaskets dry up from lack of use and start to leak. One place to check for leaks is the front seal that stops fluid from coming out of the transmission where the torque converter hub enters the front pump assembly.

Another area to look at is the transmission pan gasket. Sometimes a leaking transmission pan can result from someone over tightening the transmission pan bolts. Doing so causes the gasket to be squeezed out and the result is a leak. You might also want to take a look at the seals that keep fluid from coming out of the transaxle where the two front wheel drive shafts enter the transmission.

4T80E pan torque sequence


Failure of the modulator. This is another pretty common problem with this transmission. If it’s shifting oddly, locate the modulator and pull the vacuum line off. If the line has fluids in it, then replace the modulator. In older vehicles that sit for long periods of time the diaphragm inside the modulator can get old and dried out, causing it to crack. The vacuum from the motor will pull transmission fluid into the line, in the same way a straw pulls soda from a soda can.

These are a only a few of the more common problems with the 4T80E transmission. Sometimes units get too damaged for simple repairs – when this is the case, I recommend picking up a remanufactured transmission.

re-manufactured transmission will include major alterations and upgrades designed to make them both stronger and more durable. A re-manufactured transmission will also include a much better warranty; three years compared to an average 90 days for a rebuilt transmission. As a bonus, in the rare event that a re-manufactured transmission fails within the warranty period, they will cover your R&R cost to replace your customer’s transmission. And remember, the companies that re-manufacture transmissions are very easy contact. They are just a quick phone call or email away from helping you out.


Everything You Should Know About Automatic Transmission Pans

Posted by on Wednesday, January 16th, 2013

So you own an automotive repair shop and thing you know everything about automatic transmission pans? This could be a true statement, then again it might not. Let’s take a look at things every shop owner should know about automatic transmission pans.

Transmission pan identification chart


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Facts About Automatic Transmission Fluid That Every Vehicle Owner Should Know

Posted by on Tuesday, January 15th, 2013

As the owner of a vehicle, it’s important to be very careful and knowledgeable about the fluid you’re using in your transmission. Therefore, today we are going to educate you on the different types of transmission fluid used in both classic and modern automatic transmissions.

Transmission fluid is to an automatic transmission as water is to an aquarium. Some people spend hundreds of dollars on their tropical fish hobby. If they don’t maintain the right PH level and water temperature in their custom aquarium, it could cause serious damage, or death. The same rule applies to vehicles. A car is a major investment. Without the correct type of fluid, or the proper amount, the transmission will not operate correctly, and in most cases will self-destruct. Transmission fluid is used in an automatic transmission as a lubricant to provide the transmission with a way to shed excessive heat, and to act as a transmitter of power by using hydraulic pressure to move valves and apply band and clutches.

Transmission fluid properties


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How To Choose The Best Aftermarket Tremec Manual Transmission

Posted by on Monday, January 14th, 2013

Tremec is a well-known manufacturer of OEM performance manual transmissions and can be found in all sorts of late model muscle cars, including the Viper, Corvette, Mustang, Camaro, Challenger and many more. What a lot of people don’t know is that Tremec manufactures high performance manual transmissions for the aftermarket, too.

Let take a look a three of the most popular aftermarket transmissions Tremec makes. There are two five speed models, the TKO 500 and TKO 600. There is also a heavy duty six speed transmission called the T56 Magnum. This gives you a nice choice of transmissions to choose from when trying to make an ideal match for the motor and type of vehicle.

Inside a T56 Magnum transmission


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3 Must Have Manual Transmission Accessories

Posted by on Friday, January 11th, 2013

Almost since the beginning of the automotive industry dating back to the very early 1900’s, car and trucks of all types, sizes, makes and models have been available with a manual transmission. Some of the earliest transmissions where very crude and didn’t even include a syncro gear. The early manual transmissions were also very weak and broke often. As motors got bigger and more powerful, along with power adders supplied by the aftermarket, the manual transmission became the weakest link in the drive train. For a long time companies have been building aftermarket performance products to make manual transmissions stronger and more reliable.

Here is a short list of items you can recommend to your customer, or any one with a manual transmission, that will help improve the performance, reliability, safety and overall experience of manually equipped vehicles.

Manual transmission equipped race car


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The Need for Eight-Speed: What Drives the 2014 C7 Corvette?

Posted by on Friday, January 11th, 2013

The automotive world is abuzz leading up to the release of the all-new C7 Corvette! Automotive writers around the world have been speculating about latest model of America’s classic sports car, and leaking bits of information to pique our interest. Releasing a new model Corvette is always a risk for the General. Get it wrong, and they may lose many hard-core followers. Get it right, and they will influence the next generation of car buyers, and increase membership in the Corvette fan club. Word on the street is that the 2014 C7 Corvette will be equipped with an all-new eight-speed automatic transmission, or seven-speed manual transmission. This is General Motors first foray into the higher gear transmissions. It’s about time!

2014 C7 Corvette Design

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5 Top Products To Extend The Life Of Your Customer’s Automatic Transmission!

Posted by on Thursday, January 10th, 2013

Let’s face the facts. The economy has been horrible for the last few years and everyone is trying to save money. That means a lot of folks are not buying new cars because they cannot afford another payment. Therefore, they need to make their cars last as long as possible. We could go into all the details of each area of the car, such as body, motor, tire and more, but that would take too long. So instead we are going to focus on extending the life of your customer’s automatic transmission as long as possible.

Replacing an automatic transmission can be a major expense. The problem is that most customers don’t think about their automatic transmission until it fails, then they are shocked at the cost to replace it. As a reputable repair shop, it is your duty to inform your customer that there are ways of extending the life of their automatic transmission.

You need to act as a trustworthy friend, and give your honest opinion. Customers by products and services from people that they like and trust, even basic sales training will teach you that. This is a win-win situation for the both of you. You make a few bucks on marking up the parts and the install, and your customer’s transmission lasts longer, saving them money over the long term. Good customer relationships will lead to long term customers, more repeat customers and the growth of your business by your customer’s word of mouth.

Earn your customers trust by helping them extend the life of thier transmission


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Choosing The Best Aftermarket Automatic Shifter For Your Vehicle

Posted by on Wednesday, January 9th, 2013

You finally got that freshly re-manufactured transmission in your customers project vehicle and now it’s time to look at your options for an aftermarket performance shifter. Here is a quick description of the type of shifters on the market and how they differ from each other to help you make your choice.

aftermarket ratchet shifter in a Z28


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The Chrysler A404: Be Prepared For Problems

Posted by on Tuesday, January 8th, 2013

Chrysler first built the A404 transmission in the late 1970’s for duty in their compact line of cars. The first car built with this transmission was the Dodge Omni. The Chrysler A404 was only built for a few years and was phased out of production in 1981 (it was replaced with the A414 transmission). The A404 is a very light duty, front wheel drive, three speed transmission. It was most commonly put behind the small 1.7 liter inline-four engine that Chrysler sourced from VW. The A404 used a 2.69:1 first gear ratio, a 1.55:1 second gear ratio, and a 1:1 direct drive final gear ratio.

Soft parts from an A404 transmission


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Problems With The Ford AX4S Transmission: What You Need To Know

Posted by on Monday, January 7th, 2013

The AX4S is a 4 speed trans-axle developed by Ford for front wheel drive vehicles. The AX4S comes from a family (in this order from oldest to news) of transmissions that includes the AXOD, AXOD-E, AX4S and the AX4N/4F50N. Although the first transmission in this family was introduced in 1989, the AX4S did not go into production until 1993. It was used in the Lincoln Continental, Ford Tarus, Sable and Windstar. It was discontinued after the 1993 model year and replaced by the AX4N/4F50N.

exploded view of the AX4S Transmission


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