More opinions on my shift lever vibration please
03-28-2010, 02:47 PM
#1
Rennlist Member
Thread Starter
More opinions on my shift lever vibration please
Did some more testing this morning to try to diagnose the cause of my severe shift lever vibration at 5000 rpm and I have some new information.
It begins promptly at 5K rpm. I started in first and took it to 5k, about 35 mph. If I ease off the gas the vibration goes away quickly. However, if I let off gas and depress the clutch the engine quickly drops to idle but the vibration continues, slowing down gradually (5 seconds or so) as the car coasts down the road. The vibration appears to be rpm sensitive to start, but not to stop. To me this eliminates motor mounts as the cause.
I also brought the rpms up while stopped in neutral. If I do this with the clutch out (engaged), the vibration comes on at 5K. If I depress the clutch, the engine drops quickly to idle, but the vibration only slowly stops. I can depress the clutch at idle in neutral and take the engine to 6k with no vibration.
Does this mean torque tube bearings?
All opinions welcome and appreciated.
It begins promptly at 5K rpm. I started in first and took it to 5k, about 35 mph. If I ease off the gas the vibration goes away quickly. However, if I let off gas and depress the clutch the engine quickly drops to idle but the vibration continues, slowing down gradually (5 seconds or so) as the car coasts down the road. The vibration appears to be rpm sensitive to start, but not to stop. To me this eliminates motor mounts as the cause.
I also brought the rpms up while stopped in neutral. If I do this with the clutch out (engaged), the vibration comes on at 5K. If I depress the clutch, the engine drops quickly to idle, but the vibration only slowly stops. I can depress the clutch at idle in neutral and take the engine to 6k with no vibration.
Does this mean torque tube bearings?
All opinions welcome and appreciated.
03-28-2010, 02:54 PM
#2
Rennlist Member
Jim, when you take the engine to 5K with the clutch engaged the torque tube is also turning at 5K. When you step on the clutch and take your foot off the gas the engine goes to idle BUT the torque tube takes longer to slow down (the 5 sec.). The torque tube is also spinning the transmission input shaft and whatever gear you happen to be in so it has a lot more inertia or flywheel effect to keep it spinning. IMHO this is torque tube bearings and nothing else.
03-28-2010, 09:49 PM
#5
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Jim, when you take the engine to 5K with the clutch engaged the torque tube is also turning at 5K. When you step on the clutch and take your foot off the gas the engine goes to idle BUT the torque tube takes longer to slow down (the 5 sec.). The torque tube is also spinning the transmission input shaft and whatever gear you happen to be in so it has a lot more inertia or flywheel effect to keep it spinning. IMHO this is torque tube bearings and nothing else.
Nicely explained and nothing we can add.
