Reasons For Buick Transmissions Problems: How To Treat Them?

One of the complaints of Buick drivers is the Buick transmissions problems. They often hear rattles when shifting gears, and the shifting process is no longer smooth as usual.

What are the reasons? How to fix it? Let’s discover.

What Are Buick Transmissions?

Buick Transmissions

The Buick transmission, or Buick Dynaflow Drive gearbox, is a five-speed transmission designed by the Buick Motor Division of General Motors in 1947.

Although the Dynaflow name was dropped after 1963, its construction and operation still remained unchanged.

Like other transmissions, the Buick Dynaflow transmission supports the shifting of the vehicle’s engine. It is mounted to the motor shaft to transmit power to the wheels.

This transmission has a five-element torque converter and a torque multiplication conversion.

It consists of a Dynaflow twin turbine, a core automatic transmission, and a single stator. Besides, it has a gearwheel with forward and reverse speed automatic.

By moving the gears, the automatic or manual transmission ensures the engine RPM (Revolutions per Minute) is maintained at a low level.

It provides smooth gear shifting, helps control and limit fuel consumption at highway speed (even in performance cars). Thereby, it ensures the engine is not overheated.

Reasons For Buick Transmission Problems

Broken modulators, accumulator pistons, or bad sensors are the most common sources of transmission problems in Buick transmissions.

In addition, transmission fluid leakage can be named as a popular reason.

Reasons For Buick Transmission Problems

Modulator Problems

The modulator is the part attached directly to the transmission to control the shift operation. If the modulator valve fails, the transmission will not shift as well as normal.

A broken modulator will cause the gears to slip, so you can’t control transmission shifting and the dependent engine speed.

In addition, the worn-out valve body will cause transmission oil to leak out, be sucked in by the intake manifold, and be burned by the engine.

It will trigger the engine to overheat, leading to increased friction, and engine components will begin to rust.

Therefore, a bad or broken modulator will shorten the life of a Buick transmission.

If you detect some signs, such as too early or too late shifting or low transmission fluid, then the problem is in the modulator.

Broken Accumulator Piston

The next culprit behind the transmission shifting suffering is the broken accumulator piston.

The accumulator acts as a shift modifier, helping to control and adjust the dependent engine speed and the transmission time.

The accumulator has a simple design with a spring, drive ratio, a rear suspension design, a shift quadrant, and a plastic piston.

When these parts work with the rear wheel, they will allow smooth shifting in the gearbox.

When the actuator operates, the pressure in the circuit will increase. The piston is forced down by the spring along with the internal pressure, which helps to soften the shifting process.

If the piston is damaged or broken, it will cause the accumulator to fail, leading to a drop in gear ratio.

It will result in harsh shifting, which affects the engine and reduces the level of performance of the car.

Sensor Problems

Bad sensors are also to blame for erratic shifting. This speed sensor is responsible for detecting the input and output speed of the acceleration gears during transmission and sending this information to the control unit.

These sensors will determine drive pressure and planetary gearset operation.

When these sensors fail, many problems will arise during shifting. Once the data it receives is incorrect, then erratic, soft, or slips shifting may occur.

Rough or hard shifting due to receiving incorrect data from the motor is a source of transmission actuator malfunction.

It will lead to a slow acceleration and end up with damage to other transmission components. If this situation continues, the driver’s safety will be affected.

Other Problems

Other problems are clunking sounds and transmission fluid leakage.

Supposing you detect these annoying noises, the transmission is having some trouble. In addition, the gearbox failure also stems from its fluid leak.

It is caused by the engine overheating, which makes parts such as valves, element fluid coupling, or proof systems wear out.

As a result, the transmission suppliers will leak, causing the transmission to malfunction.

How To Deal With Buick Transmission Problems?

Replace Broken Parts

If you find any damage on the modulator valve body, piston, or transmission leak, you should replace them with new ones.

Once the actuator leaks, you can look for the cause in the pipes, washers, or plugs.

Also, should the transmission fluid leak, you can replace it to avoid overheating or increasing the engine RPM. You can manually drain the old fluid and replace it with a new one.

Remember to read the instruction manual provided by the manufacturer to avoid transmission slipping after changing fluid.

Besides, the pressure in the circuit is also affected by the solenoid and the transmission linkage.

If the links or the element fluid coupling phase become loose, you need to tighten them or replace them when you find them broken.

Visit Transmission Repair Facility

Let’s say you are unfamiliar with fixing these problems; you can go to the Buick Transmission repair facility or another automatic transmission repair shop.

Repairing or replacing the faulty transmission can be quite expensive for Buick LeSabre, Buick Century, or CID Buick.

A transmission specialist or technician can do the replacement of the gearbox. They also have excellent customer service, providing useful ways to avoid damaging the transmission and prolonging its life.


What Does a Transmission Repair Cost?

The faulty transmission repair is quite expensive due to the complex automatic transmission assembly. However, depending on the degree of damage, the price will also vary.

Usually, the transmission leaks due to cracked or worn fluid coupling. The cost of these replacement transmission parts may be higher than other parts.

Draining the fluid and replacing the new fluid will be cheaper.

In addition, it is not very expensive to tighten loose links or loose paths. This repair cost varies differently depending on the shop you visit.

Buick repair shops will have the exact Buick transmission cost for fixing. Other auto shops may have higher or lower prices based on their service.

What Are Common Symptoms Of a Bad Buick CVT Transmission?

One of the signs that you have a bad Buick transmission is delayed shifting after you push the shift lever forward and turn the steering wheel.

In addition, the clicking noise is also a symptom of a damaged transmission, showing a low degree of engine braking.

How To Maintain Buick Transmission?

One of the best ways to do that is to have your vehicle regularly serviced at a repair facility.

In addition, you need to maintain the habit of warming up the ignition before driving. It will help limit the pressure on the transmission.


Modulators, accumulator pistons, sensor malfunction, and transmission fluid leakage are the common reasons for Buick transmissions problems.

When you find them malfunctioning, you can take them to a repair facility for a variable transmission replacement.

Hope you find this post helpful. See you in the next ones.

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