While your manual transmission vehicle will offer you an engaging driving experience, it will also come with transmission problems. This is because the constant shifting of gears leads to constant rubbing and heating up of many interconnected parts within the manual transmission system. For this reason, the constant friction and heating of these transmission components means that they are bound to constant wear and tear. Transmission repairs are usually expensive and that's why it's important to identify problems as early as possible before they develop into something more complex. Therefore, here are some causes of a manual transmission that won't shift.
The transmission fluid should be the first thing you check when your manual transmission won't shift. Since the transmission system contains a lot of moving parts, the fluid is necessary to minimise friction and build-up of heat, which can cause other transmission problems. When was the last time you checked or changed your transmission fluid? Make it a habit to check and change the oil periodically even before your next scheduled auto service. You may not be able to easily tell when the fluid is low and that's why constant checking is important. In addition, if you notice that your manual transmission won't shift mostly in cold weather, you should consider changing the type of fluid that you use.
Clutch Disk or Pressure Plate
To determine whether the problem lies within the clutch disk or pressure plate, you need to know when the shifting problems occur. Therefore, if you can't shift a gear when your vehicle is moving, but you can when the engine is off, then you might want to have the clutch disk or pressure plate checked by a mechanic. This is because the only way to tell whether the clutch disk or pressure plate is the problem is to dismantle the bell housing of your transmission and checking for wear and tear of the disk or plate. If they are worn, replacing them should solve your manual transmission problem.
Listen for a grinding and clashing gear any time you shift between gears. If the gear is grinding or clashing, you will hear grating sounds when you shift gears. A grinding gear may be a result of faulty synchronisers. These are very important features that will lock a gear in the required speed with your engine when you shift between gears. These synchronisers have springs, which when are faulty or worn, may result in shifting problems.
For assistance with your manual transmission, talk to a professional.