In this article, we go over some of the most common problems with Opel automatic transmissions and common causes. 

No Torque Converter Clutch Lock-up

Opels with a 6-speed 6T40 transverse automatic transmission, designated as Hydra-Matic, can suffer from inoperable TCC lock-up. In some cases, the TCC will lock-up in a very harsh manner. In general, this will have a negative impact on fuel economy and can even cause transmission fluid overheating.

The TCU will detect if there is an issue with TCC engagement and trigger a check engine light, so there will be corresponding code.

Possible causes and solutions

• A worn or stuck TCC regulator-apply valve, which should ensure a smooth TCC engagement. If worn, it will cause a significant loss of pressure, resulting in the lack of ability to engage the TCC assembly. If stuck in the ON position, it will cause harsh engagement. There are oversized kits available, which will restore normal TCC operation. 

Slippage when going into 2nd or 3rd gear

Older Opels that use a 4-speed 4L30-E automatic transmission in longitudinal configuration have a fairly common issue that affects upshifts. It will show up as slippage or delay when shifting into 2nd or 3th gear during accelerations.

In more severe cases, this can also cause harsh gear changes coupled by a noticeable shoulder. This issue is likely to trigger a check engine light, meaning there will be a code stored in the DTC memory. 

Possible causes and solutions

• Distorted or deteriorated housing gaskets, causing pressure leaks and affecting the quality of gearshifts. The root of the problem are the gaskets themselves, as the OEM ones are too thin. As a result, it is not possible to generate enough force to ensure sufficient sealing. The solution is to install upgraded gaskets made by Interface Solutions Inc., which are thicker than the OEM gaskets (.015”) and more compressible. 
• Sticking or clogged solenoids, as a result of neglected transmission fluid changes. Performing a thorough transmission fluid flush can sometimes help. 

Not starting coupled with ‘F’ letter on the dashboard.

Smaller Opel cars that use an automated transmission called Easytronic have a common problem, which will render the car inoperable. The symptoms are a letter ‘F’ that will be illuminated on the dashboard, and the car will refuse to start. In most cases, there will be one or more related codes stored in the DTC memory. 

Possible causes and solutions

• Faulty Gearbox clutch actuator control module, which operates the clutch itself. Being a robotised transmission with a dry clutch, this failure will make gearshifts impossible. The most common error codes are P1607, P1732 and P1735. These units are coded, meaning that replacing it with a second-hand working part is not an option. Rebuilding the actuator by a specialist is the only feasible option. 

No reverse and some of the drive gears

Opels that use a 6-speed 6T40 transverse automatic transmission, designated as Hydra-Matic, have a fairly common set of issues. They will manifest themselves either as a loss of reverse together with 3th and 5th gear. Usually, this will happen out of sudden and will not go away when the engine cools down.

In most cases, this issue will not trigger any warning lights on the dashboard. 

Possible causes and solutions

• Broken 3-5-R waved plate, which is responsible for engaging affected gears. If it breaks apart, it can damage the drum splines and the housing itself. As this is a well-known and common problem, there are rebuild kits that use upgraded and more durable parts. Many transmission specialists recommend replacing affected parts as a preventive measure, even when there are no symptoms. 

Shift flares and harsh downshifts.

Opel Vectra and Antara equipped with Aisin AW55 5-speed automatic transmission suffer from an issue that is quite common. This will show up as intermittent shift flares during accelerations that affect upshifts from 2nd to 3th gear.

Sometimes, this will also cause harsh downshifts from 3th to 2nd. At start, this will be more prominent when the vehicle is cold but might get worse with time. In most cases, this issue will trigger a check engine light, meaning there will be a trouble code stored in the DTC memory. 

Possible causes and solutions

• Worn valve body bores, causing loss of transmission fluid pressure or valve movement obstruction. The failure mode depends on the position and the nature of the wear. This is a very common problem caused by the fact that the material for the solenoid valve material is harder than the valve body itself. When examining the valve body, check for wear marks and replace it if there are any.
• Wrong type of control valve installed, as different variants either have or don’t have a control spring. This is something that can easily happen during transmission repairs and can result in sporadic 2-3 gear shift issues.

Opel vehicles are fun to drive and generally inexpensive to maintain. We recommend to have the transmission serviced at the recommended interval to minimize potential issues down the road.