VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc Transmission/clutch chatter

I have a 47 Stylemaster that is giving me lots of chatter in first gear when taking off but smooth in the other gears when the clutch is depressed. I understand the need for new motor and transmission mounts with the proper alignment from the manual.
I looked that up and don't understand this portion:
3. Check the clearance between the transmission cross member and the "U" section plate (pas­senger models only). This clearance should he from .005" to .015", equally spaced fore and aft. If the clearance exceeds these limits, remove the mounting and bend the "U" section plate until the clearance is within the above limits.
What is the "U" section plate they are talking about? Pic would have helped me...visual guy!
Thanks for your time and advice.

Hello WG1,

I do not have a '47 but in the spirit of trying to help answer the question. The "U" section plate may be the transmission plate the rubber is vulcanized into for the transmission mount assembly. That will bolt to the transmission, and the transmission cross member. I suspect it is the transmission cross member they are telling you to bend so the rubber in the mount is not preloaded in one direction or the other. That way it should not touch metal to metal and transmit road and engine noise.

Another cause of first gear chatter is too much engine thrust bearing clearance. A lot of people sit too long such as through a stop light with the clutch pressed in. Do it enough times and it is really hard on the engine thrust bearing. As the clutch is let out essentially the crankshaft bounces back and forth in the engine making the clutch grab and chatter. If the rubber in all the mounts are soaked with oil and worn out it will greatly exaggerate the chatter.

Please let the forum know what you find. I can guarantee other people are having the same or a similar problem.