Is Transmission Dismantling Necessary When Fifth Gear Cannot Be Engaged?
3 Answers
Is transmission dismantling necessary when fifth gear cannot be engaged? Below are methods to distinguish between dry and wet DCT transmissions: 1. Whether the clutch plates are immersed in transmission oil: Dry dual-clutch plates are not immersed in transmission oil; Wet dual-clutch plates are immersed in transmission oil. 2. The connecting medium between the driving and driven discs in the clutch differs: Dry dual-clutch uses air as the connecting medium; Wet dual-clutch uses oil as the connecting medium. 3. Different usage scenarios: Generally, dry types are used for short-duration semi-clutch states; Wet types are mostly used in automatic transmissions, such as the now commonly used manual-automatic integrated transmissions.
Last time I fixed my old Passat, I encountered the same issue. Actually, there's no need to rush into removing the transmission. First, squat down and check the shift linkage—it's most likely due to worn or stuck bushings. Spray some WD-40 on the moving joints and manually wiggle the shift lever to test. If you feel obvious resistance when shifting gears but no strange noises, it's probably this issue. Replacing the bushings yourself only costs about twenty bucks, much easier than dealing with the transmission. Of course, if the shift fork is bent or the synchronizer ring is damaged, then you really will need to remove the transmission. I suggest first taking it to a repair shop to inspect the clutch disc wear with a borescope before rushing to dismantle the engine.
Having repaired manual transmissions for over a decade, there are three scenarios for fifth gear engagement failure: If it engages when cold but not when hot, it's likely due to viscosity changes in transmission fluid under high temperatures—try switching to a full synthetic 75W-90 oil. If it engages when stationary but not while driving, focus on checking the clutch release bearing travel. A special case involves deformed shift cables, especially in cars with aftermarket exhaust systems where thermal expansion presses against the shift mechanism. Just two days ago, I fixed a Volkswagen Bora by finding a misaligned stopper under the dust cover—adjusted with a wrench in five minutes. Unless there's internal rattling noise, major disassembly is rarely necessary.
