Transmission
#transmission
#gear
#judder
#ZF specialist
#service
#sport mode
#fifth gear
#fourth gear
#incline
#vehicle
Description: The automatic transmission experiences a judder in fifth gear only, which is more pronounced when climbing an incline. Engaging sport mode and shifting down to fourth gear eliminates this judder. After consulting a local ZF specialist, a service was performed, but it did not resolve the issue. The specialist suggested that the torque converter needed refurbishment. The torque converter was subsequently removed, refurbished, and reinstalled along with a new oil and filter while the transmission was out. Despite replacing the torque converter with a brand new Land Rover part, the judder persists at speeds between 55 and 60 mph. The old torque converter was removed with clean oil and no burnt smells. The next step involves inspecting the valve block for potential issues with the valves controlling the lock-up clutch. Although the transmission operates well with fresh, correct fluid, a vibration is still present at speeds between 55 and 65 mph. Engine misfire diagnostics have been performed, as the engine management light occasionally activates, which may be linked to the transmission judder. The individual reporting this issue runs a large BMW dealership and notes that this problem is uncommon with similar transmissions in their vehicles.
The automatic transmission system described consists of several critical components, including the torque converter, valve block, and the control system that manages gear shifting and lock-up clutch engagement. The judder occurring exclusively in fifth gear indicates a potential issue with the torque converter's lock-up mechanism or the valve block responsible for regulating fluid flow to the clutch.
The torque converter, which has been refurbished and replaced, plays a vital role in coupling the engine to the transmission, allowing for smooth acceleration and deceleration. The refurbishment process typically involves cleaning, replacing worn components, and ensuring that the unit operates within specified tolerances. The mention of clean oil and the absence of burnt smells upon removal suggests that the torque converter itself was not excessively damaged, but rather that the issue may lie within the control mechanisms.
The valve block is a critical assembly that houses various solenoids and valves that control hydraulic pressure and fluid flow within the transmission. Anomalies in the valve block can lead to improper engagement of the lock-up clutch, resulting in vibrations during specific speed ranges. The inspection of the valve block should include testing the solenoids for proper operation and checking for any blockages or leaks that could impair hydraulic function.
The engine management light activation may indicate a miscommunication between the transmission and the engine control unit (ECU). This could be due to the judder affecting the engine's performance, leading the ECU to register a fault. It is essential to ensure that the transmission fluid level is correct and that the fluid used meets the manufacturer's specifications, as incorrect fluid can also contribute to shifting issues and vibrations.
In summary, the judder experienced in the automatic transmission could stem from a combination of factors, including the torque converter's operation, valve block functionality, and potential interactions with the engine management system. Further diagnostics and inspections are warranted to pinpoint the exact cause and implement an effective solution.To the automatic transmission, there is a judder throught the box in fifth gear only and is more pro nounced when climbing an incline. If you knock it into sport mode and thus change down to fourth gear this judder disappears, it has been to the local ZF specialist!
i was informed that a service should cure this problem and this was done. As you can guess this did nothing and when i asked why i was told i would need to drive it for a few days for it to come good( ha ha), when this didnt happen i was informed that the torque converter needed to be refurbished. I then took the box out and took the converter to the local torque converter place and had it refurbished, and oil and filter was then carried out will the box was out and the torque converter was re install with box.
I have just replaced the torque converter with a brand new Land Rover part at great expense and the judder at 55-60 mph is identical sadly. The old one came out with clean oil and no burnt smells. I am now going to look at the valve block to see if the valves that control the lock up clutch could be causing the problem.
With some fresh correct fluid the box changes and operates brilliantly in every way except between 55 and about 65 mph where I get a vibration much like everyone else describes. Ive done all the engine misfire tricks as occasionally the EML light comes on which we believe is the judder in the gearbox fooling the engine management system.
Will let you know how it goes and feedback! Amazingly I run a big BMW dealership for a living and we never get this problem on our cars with this box so my boys are as lost as me!
The automatic transmission system described consists of several critical components, including the torque converter, valve block, and the control system that manages gear shifting and lock-up clutch engagement. The judder occurring exclusively in fifth gear indicates a potential issue with the torque converter's lock-up mechanism or the valve block responsible for regulating fluid flow to the clutch.
The torque converter, which has been refurbished and replaced, plays a vital role in coupling the engine to the transmission, allowing for smooth acceleration and deceleration. The refurbishment process typically involves cleaning, replacing worn components, and ensuring that the unit operates within specified tolerances. The mention of clean oil and the absence of burnt smells upon removal suggests that the torque converter itself was not excessively damaged, but rather that the issue may lie within the control mechanisms.
The valve block is a critical assembly that houses various solenoids and valves that control hydraulic pressure and fluid flow within the transmission. Anomalies in the valve block can lead to improper engagement of the lock-up clutch, resulting in vibrations during specific speed ranges. The inspection of the valve block should include testing the solenoids for proper operation and checking for any blockages or leaks that could impair hydraulic function.
The engine management light activation may indicate a miscommunication between the transmission and the engine control unit (ECU). This could be due to the judder affecting the engine's performance, leading the ECU to register a fault. It is essential to ensure that the transmission fluid level is correct and that the fluid used meets the manufacturer's specifications, as incorrect fluid can also contribute to shifting issues and vibrations.
In summary, the judder experienced in the automatic transmission could stem from a combination of factors, including the torque converter's operation, valve block functionality, and potential interactions with the engine management system. Further diagnostics and inspections are warranted to pinpoint the exact cause and implement an effective solution.To the automatic transmission, there is a judder throught the box in fifth gear only and is more pro nounced when climbing an incline. If you knock it into sport mode and thus change down to fourth gear this judder disappears, it has been to the local ZF specialist!
i was informed that a service should cure this problem and this was done. As you can guess this did nothing and when i asked why i was told i would need to drive it for a few days for it to come good( ha ha), when this didnt happen i was informed that the torque converter needed to be refurbished. I then took the box out and took the converter to the local torque converter place and had it refurbished, and oil and filter was then carried out will the box was out and the torque converter was re install with box.
I have just replaced the torque converter with a brand new Land Rover part at great expense and the judder at 55-60 mph is identical sadly. The old one came out with clean oil and no burnt smells. I am now going to look at the valve block to see if the valves that control the lock up clutch could be causing the problem.
With some fresh correct fluid the box changes and operates brilliantly in every way except between 55 and about 65 mph where I get a vibration much like everyone else describes. Ive done all the engine misfire tricks as occasionally the EML light comes on which we believe is the judder in the gearbox fooling the engine management system.
Will let you know how it goes and feedback! Amazingly I run a big BMW dealership for a living and we never get this problem on our cars with this box so my boys are as lost as me!