MG Car Repair: MG Midget Clutch/transmission question, clutch fluid, clutch release

Question
QUESTION: Well, you helped me with a silly turn signal issue, now I have something more troubling. When taking it out for a drive today, the clutch wouldn't engage. Determined that the master cylinder was out of fluid. NOt sure why. It's old. Put in new fluid and it engaged just fine. Now there is a metallic noise when driving and it sounds like it's coming from the transmission, but I can't replicate unless I am in motion. It might help to know that it sounds louder and more "banging" when the car goes over bumps? There is no noise at all when the engine is idling and no noise when shifting (except, as noted, if I am going over a bump) - It's hard to figure because it only happens while moving.

Thanks again for your expertise.

Kit

ANSWER: Hi Kit.  If you have lost clutch fluid, then you must trace the leak.  Usually, either the slave cylinder under the car needs a rew seal, or the flexible hose to the cylinder needs replacing.  On some earlier cars there was no flexible hose, relying on the flexing of the metal pipe to take up any movement.  The metal pipe can develop a small crack as it flexes.  

Also, look up inside the driver's compartment above the clutch pedal.  Is there a pedal return spring?  These often break, after which the pedal doesn't fully retract and the carbon release bearing permanently touches the clutch release ring.  The banging could be the release bearing thumping against the clutch when you go over a bump.

---------- FOLLOW-UP ----------

QUESTION: Thank you again. The issue SEEMED to be bad motor mounts (the problem got progressively worse after my initial email to you). I had those replaced, as well as the transmission mounts and the brackets that hold the exhaust. But there is still SO MUCH vibration when I drive it. The mechanic is in denial and keeps telling me that "these cars always vibrate like that..." I know better - but I can't seem to find the reason. The banging noise is gone since the motor mount job, but the vibration seems worse. Could it be a total coincidence that they both happened at the same time and this could be a whole other issue?

Answer
Hi Kit.  There should not be vibration when you drive the car.  Something is out of balance.  

I am suspicious that the propshaft (driveshaft) may be out of balance, possibly needing a new universal joint.  Has your mechanic checked them both (front and rear)?  

Also, vibration at a set speed (such as 55mph) can be down to wheel balance.  If you can accelerate through the problem so it goes away at (say) 60 mph then the problem is that the wheels need re- balancing.