Vibration / Under powered

C

CJH

Member
Let me begin by saying that I know there are multiple answers for my questions and diagnosing a problem such as this with out putting hands on the car is difficult at best. I have my ideas about what is wrong, however, I am sure that the collective knowledge and experience of the Ford Barn will produce a few new ideas to consider.

I have a vibration that begins around 800 - 1000 RPM. Below this RPM level I do not notice the vibration. It happens sitting still, in gear or out of gear, clutch in or clutch out.

I also get a sight whine when driving in first and second gear, but not in third.

And finally the car seems to max out at 45 MPH. At this speed the vibration is in full swing.

There is no knocking associated with the vibration, just shaking.

Details; 1930 Town Sedan; <500 miles on rebuilt touring engine from H&H, Mitchell transmission, purchased a rebuilt U-joint, had the flywheel balanced (but not by a model A guy/shop).

Thanks for your time,

Chris
 
Here is my 2 cents worth...The under power may be due to point gap and/or timing. It is possible that a valve(s) have closed down. If you are not getting a vibration in nuetral and not going anywhere that should leave out the ****** on back. Good Luck.

Mike
 
Whine in first and second gear is normal. Transmission gears are straight cut in the model A and they whine. No whine in high gear, be cause no meshed gears are under strain, it is direct coupling in high.
Vibration that is excessive is often caused by out of balance rods. Some vibration is normal, it is a 4 cylinder engine, and all 4 pistons stop and restart every half revolution, which causes vibration at certain speeds.
 
Does it sound like irregular ignition? Like pistons are firing sporadically? I'm wondering if the points are making reliable contact. Perhaps the points spring is missing or not engaged and the points are flopping around and not making positive contact between cam lobes.
 
Thanks for all the quick replies. 2manycars, thanks for the response about it being normal. I am going to arrange a ride in another "A" to listen to that noise and see how many other things I worry about are normal for the old car.

I am going over to my Dad's house and will listen carefully, but it seems that all cylinders are firing normally. I'll get back to you guys about that one.

Thanks again,

Chris
 
CarlG, believe me when I say if I had the time and means to get get to Alaska to check out your center main, I would already be booking my flight. I have always wanted to see Alaska!

Do you have a picture? What happened?

Thanks for your reply,

Chris
 
I wonder if the vibration is from the u-joint. Does it vibrate revving the motor in neutral?
As for low power, others will surely chime in.
 
One day while on a search for vibrations, i discovered that a prior owner had tightend the front motor mounts down so tight that the springs could not offer any kind of vibration absorbtion. I backed the nuts off a couple of turns, re-keyed them and eliminated one of my most serious vibrations.
 
gweilbaker said:
I wonder if the vibration is from the u-joint. Does it vibrate revving the motor in neutral?
As for low power, others will surely chime in.
Click to expand...

Yes the vibration is there while revving the motor in neutral.

I'll also check the front motor mount.

Thanks for all the help. We'll get this one yet!

Chris Hall
 
Have you tried this?

Remove the distributor cap, body, and rotor. Grasp the distributor cam with your thumb and forefinger, and attempt to rock or move the shaft back and forth. There should be no discernible movement laterally. Any movement indicates worn bushings and/or shaft. The distributor will still function, but the point gap will vary by a corresponding amount. Keep in mind the recommended point gap is .018"-.022", not .013"-.027"!
Click to expand...
FYI, this comes from Marco Tahtaras at the link below.

http://www.abarnyard.com/workshop/timing.htm
 
Newshirt

I did get a little bit of forward and aft movement out of the distributor. There was no movement side to side at all. And it was the whole distributor moving not just the cam. I'll be checking that out today.
Thanks for the help.

Chris
 
Well, we re-timed the Town Sedan today before the football game started and were able to get some positive results. We followed Marco's instructions to the letter, it ran much smoother and we picked up a little speed.

It still has the vibration, although some what reduced. I'm sure that the vibration is coming from the flywheel. Either not balanced correctly or not mounted correctly, we'll soon find out!

Thanks to Newshirt for steering me towards Marco's site, and thanks Marco for the informative web site.

Chris
 
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