help with vibrating mirror !
- Thread starter al's28/33
- Start date
Big hammer
Well-known member
In your phaeton? Cork does a nice job for quieting down vibrations, if you don't squeeze it to much.
CWPASADENA
Well-known member
The 33 Pick-Up originally did not have an inside rear view mirror, only an outside mirror on the left side. You may try making the mirror bracket very stiff. Any springiness in the bracket will accentuate the vibration.
My opinion,
Chris W.
My opinion,
Chris W.
nkaminar
Well-known member
Does anyone else remember this: Many years ago there was an article about how to analyse the reflection in the vibrating rear view mirror to determine engine problems. If it was jumping up and down it was a rod bearing or side to side a main. I am pretty sure it was a spoof, more humor than fact.
Patrick L.
Well-known member
Oldbluoval
Well-known member
If the header is vibrating….the mirror will do the same. Maybe worse as it is extended and gets more leverage/wiggle room
MikeK
Well-known member
The mirror vibration problem also often occurs on modern cars when you replace a broken side mirror glass with a cheapo non-factory piece. WHY??-
Every object has what's called a 'period of motion'. That's basically the frequency at which it will swing/vibrate when given one impulse of inertial movement. Mounted automobile mirrors are like clock pendulums. Change either the distribution of mass or the length of the arm and the period of motion changes. When the vibration of the vehicle approaches any mathematical relation to that period of motion the mirror will go into a harmonic and vibrate strongly.
Modern cars that suffer after a non-factory cheapo mirror replacement have less mass and incorrect mass distribution. The fix there is to epoxy some weights to the back side edges of the glass.
To fix the mirror on a Model A, in addition to isolation mounting as suggested above, you need to increase the mass which will lower the frequency of motion. I have tamed several add-on exterior mirrors by opening or drilling the external SS case and filling the void with #7 lead shot.
Every object has what's called a 'period of motion'. That's basically the frequency at which it will swing/vibrate when given one impulse of inertial movement. Mounted automobile mirrors are like clock pendulums. Change either the distribution of mass or the length of the arm and the period of motion changes. When the vibration of the vehicle approaches any mathematical relation to that period of motion the mirror will go into a harmonic and vibrate strongly.
Modern cars that suffer after a non-factory cheapo mirror replacement have less mass and incorrect mass distribution. The fix there is to epoxy some weights to the back side edges of the glass.
To fix the mirror on a Model A, in addition to isolation mounting as suggested above, you need to increase the mass which will lower the frequency of motion. I have tamed several add-on exterior mirrors by opening or drilling the external SS case and filling the void with #7 lead shot.
J Franklin
Well-known member
Counterbalances on the crank and a full balance of the reciprocating parts will help. Maybe a harmonic balancer up front would be a good touch. Back in the day there was no problem with a dancing mirror because the model A was so far ahead of all the other cars on the road!Counterbalances on the crank and a full balance of the reciprocating parts will help. Maybe a harmonic balancer up front would be a good touch. Back in the day there was no problem with a dancing mirror because the model A was so far ahead of all the other cars on the road! except the 6 cylinder chevys!!!!!!!!!!!!!!!!!
Chevy outsold them by a ton.
Ivan in southeast va.
Senior Member
Might try a rubber faucet washer.