Gearshift Doesn’t Return? Try to Check the Return Spring of the Shift Shaft!

001-5.jpg How to

Whether upshifting or downshifting, it is natural for the pedal to always return to the same position after operating the gearshift. That's the reason why I get impatient when I can't get the brake pedal back on. In such cases, forcing the pedal up may help you to upshift, but it may also lead to major problems, so it is necessary to determine the cause and make appropriate repairs.

Poor lubrication or poor angle of the change link can cause deterioration in operability.

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The thicker spring is the return spring for the shift shaft, and the thinner one is for the shift pawl. The end of the return spring is V-shaped. When setting it on the engine, the V-shape is opened and hooked onto the return pin. When overhauling or restoring an engine, it should be replaced regardless of whether it is damaged or not.

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The spring is inserted into the shaft part of the shift shaft and both ends of the V-shape are opened wide and hung on the pawl. The tension of the gearshift is strong enough to bring it back to the neutral state whether you step on it or scrape it up, but the stronger it is, the more likely it is to break at once.

Lighting comfort is greatly affected by whether or not the clutch lever and gearshift operations are synchronized. Whether you are shifting up or down, you will be able to drive rhythmically if you can shift gears with a simple click of the lever and your foot on the pedal. On the other hand, if the levers are too heavy or the pedals have friction loss, you will be distracted by them and stressed.

To improve the clutch operation, it is important to clean and lubricate the cable if it is a cable-operated clutch, and to grease the lever pivot and release arm. For hydraulic clutches, regular fluid changes and cleaning of the master cylinder and release piston are effective.

On the other hand, if the gearshift is reluctant to move or the pedal is heavy, if your model has a link between the shift shaft and the gearshift, it may be useful to review the link settings. The shift rod connecting the shift lever and gearshift at the end of the shift shaft is threaded at both ends and incorporates a pillow ball. By turning the shift rod, you can change the pedal height by moving the distance between the pillow balls closer or further apart, but the key to this adjustment is to keep the shift rod and shift lever at approximately 90 degrees.

If the angle between the shift lever and the gearshift deviates greatly from 90° due to the amount of adjustment of the shift rod, the shifting force will not be transmitted properly, causing poor operability. If the manufacturer's OEM gearshift is within the STD adjustment range, the angle between the shift rod and the shift lever should not shift significantly, but if you have to pull the shift lever out of the shift shaft, it is important to restore it so that the correct angle can be reproduced.

As a basic matter, it is also essential to properly lubricate the gearshift pivot area and pillow ball. Since the gearshift is returned to neutral by the force of the spring, it is difficult to notice any increase in friction loss at the pivot. However, by cleaning and lubricating the moving parts, the pedal can move surprisingly smoothly and the shift touch can be greatly improved. It's easy to get distracted by lubricating the clutch cable, but sometimes it helps to pay attention to the gearshift side to enjoy a comfortable ride.

POINT
  • POINT 1: If the touch of the pedal when shifting gears is reluctant, lubricate the pivot part of the gearshift or the joint part of the linkage if it is a linkage type.
  • POINT 2: The angle between the shift lever and shift rod is also important for link-type gearshift.

A broken return spring that returns the gearshift to the neutral position is often the cause of poor return.

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Change external mechanism of Kawasaki Zephyr X. The shift shaft and shift drum are exposed by simply removing the cover where the output shaft and shift shaft go through, and both the return spring and the shift pawl spring can be easily replaced.

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The oil seal for the output shaft is also press-fitted into the cover of the change external mechanism, making it easier to replace than the crankcase press-fit type seal when engine oil leaks due to aging of the seal. On the end face of the shift drum, there is a black strip with a slit in it, and this strip is touching the neutral switch on the cover side. When the shift drum comes to the neutral position, the switch terminal makes contact with the break in the strip and conducts, turning on the neutral lamp.

Friction loss due to insufficient lubrication of the clutch cable or gearshift is a type of problem that gradually increases with neglected maintenance, but there are also problems that suddenly occur with shifting gears. That is the return spring breakage of the shift shaft.

Whether you step on or scratch up the shift pedal, it returns to its original position when you take your foot off the pedal, thanks to the return spring built into the shift shaft. This spring is shaped like a safety pin, with both ends of the coiled spring extended toward the same direction, and is hung on the return spring pin.

Therefore, whether the shift shaft is turned right or left, that is, upshifted or downshifted, it can return to its original position because the position of the return spring is determined by the return spring pin. Then, when the shift shaft moves from neutral, the two shift pawls at the end of the shaft rotate the shift drum to change the transmission gear combination.

The return spring is one of the most important parts of the change mechanism, but it can break suddenly and without warning. It is not a part that wears out like a tire or clutch plate, nor does it deteriorate faster if the shifting motion is rough, and many motorcycles have never been broken.

However, if the return spring is broken, various problems will occur. First of all, the gearshift will stay down and not return. There is a single return spring attached to the shift shaft, which acts on both upshifting and downshifting. However, since the pedals itself are lowered by gravity, the symptom is lowering of the pedals.

You may think that you cannot shift up when the pedal is down (for normal change), but this is not necessarily the case. If the shift pawl integrated with the shift shaft is functioning, the shift pedal position may be unstable, but the shifting operation itself may be possible. Rather, the spring built into the shift pawl is more important in terms of the inability to shift gears. This spring pulls the two pawls that hold the shift drum from both sides together, and if it is damaged, the shift drum cannot be turned, meaning that the gear cannot be shifted.

Compared to return springs, the probability of trouble occurring is lower, but no part can be absolutely undamaged. The gearshift cannot shift toe to toe whether it is stepping down or scraping up to return to neutral position. Or, if you can only operate one or the other, it may be due to a broken spring on the pawl side.

POINT
  • POINT 1: If the return spring on the shift shaft breaks, the gearshift will stay down.
  • POINT 2: If you are unable to shift gears by operating the gearshift, the shift pawl that operates the shift drum may have a broken spring.

Spring fragments can cause secondary damage, so early repair is necessary.

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If the return spring, which is wound to the point that its ends become V-shaped, is damaged, it will no longer be able to pinch the return pin and the shift shaft will not be able to be positioned. As a result, the gearshift goes down. Since you never know when or if it will break, the trouble will come suddenly.

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If the return spring breaks, it will naturally fall into the engine. If this debris gets caught in the rotating parts, it can lead to serious problems, so if the gearshift does not return, do not just keep riding and get it fixed as soon as possible.

If the return spring on the shift shaft breaks, the gearshift will stay down, but can be raised by putting your toe further down the lowered pedal. However, there is a risk that fragments of the broken spring may fly into the rotating parts of the engine and cause damage, so it is necessary to identify the cause and deal with it as soon as possible.

Here are the shift shaft and return spring sections for Kawasaki 4-cylinder engines such as the Z1 and Zephyr, and Ducati. It was traditional for Kawasaki to mount the complete shift shaft outside the crankcase, and this was called the change external mechanism. Thanks to this, there is no need to remove the clutch basket when replacing the return spring. On the other hand, Ducati engines have the shift shaft behind the flywheel, so the flywheel needs to be removed when replacing the return spring.

Therefore, if the return spring is broken, it can be replaced by removing the cover on the back side of the sprocket if it is a Kawasaki Z series engine (including GPZ900R and ZZR series), but for engines that require the removal of the flywheel and clutch basket, the tools and equipment required for the work must be prepared accordingly.

The reluctance of the gearshift to move can be improved by cleaning and greasing, but there is no way to predict when the return spring will break. If you are riding as usual and the gearshift does not return in the middle of your ride, you should suspect a return spring problem.

POINT
  • POINT 1: Difficulty in replacing the shift shaft return spring varies depending on the structure of the engine.
  • POINT 2: If a problem occurs, stop driving and repair it as soon as possible to avoid damage to the inside of the engine from broken spring pieces.
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