Model A motor mounts

J

JBohannon

Senior Member
I am trying to reduce vibration in my A as much as possible because at about 30mph and above or higher rpms in first or second it is really bad. My engine is stock and runs pretty darn well but I am sure it is not balanced. Right now my front motor mount has only the center bolt with rubber on top and bottom of the frame. My rear mounts at the flywheel housing are bolted directly to the frame no rubber or wood at all. Could not I at least put maybe 1/4" rubber between the frame and motor at back to improve vibration some. Thanks, Newbie Joe.
 
There is supposed to be a rubber piece between the rear mounts and the frame roughly 1/4" thick and the front is supposed to have a bushing were the center bolt goes through the frame and a spring on either side of it. So to answer your question yes.
 
First,do you have stock mounts at the rear?If you do,there has to be rubber between them and the frame.If installed correctly,there is no metal-to metal contact between the rear mounts and the frame.If you have float-a-motor mounts the inside piece does bolt directly to the frame.
 
The metal bushing on the center bolt of the front motor mount yoke was discontinued sometimes in 29. It was believed that the metal bushing caused the center yoke bolt to bend.
 
I have come to the conclusion that I do not have stock rear motor mounts so I bet the rubber between the frame and engine would help quite a bit. At front it seems that all I has it the center bolt with the rubber bushing. Do I not need springs on each side. Thanks for help.
 
Joe,
Damn! THE GHOST stole my Pot Stirrin' Stick!:mad: Oh! well, here goes,:D yes, Joe, they vibrate like a ***** at higher RPM's, makes you think you're tearin' up your motor!:eek: Chief said Ol' Man Lewis' BRAND NEW SEDAN vibrated, kinda' hard to tell much because of the poor gravel roads.:confused:
On Minerva, my '30 Coupe, I put Float-A-Motor mounts, front & rear, cut the side pans loose from the motor and formed 1/8 flat stock under the pans to reinforce them, installed a flexible exhaust pipe hanger, and VOILLE' It was like a different car. Even at 40 MPH in second gear, it would just huuum along SO SMOOTHLY!:D Bill W.
 
Ok I think I will try to improve the vibration a little bit. I think I will repair the front mount since the rubber seems bad in the center bolt and I am missing the 2 side springs. And I will put 1'/4" rubber between frame and flywheel housing. Do you all think that will help some. Joe B.
 
What do your rear mounts look like? If they look like homemade steel boxes with the end towards the rear open they may be original.
 
There is a good article in the Service Bulletins, New Flexable Front Motor Support, Pages 294, 295 and 296. Although the main purpose of this article is converting the early solid front motor mount to flexable, the information on page 296 applies to the proper set up of the Flexable Front Motor Mount, when not set up properly it defeats the purpose of this mount.

Ron
 
This is what you should have on the rear mounts,from Bratton's Catalog, if
they are stock.

Bob
 

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You need to get some catalogs from some of the vendors, many have detailed pictures of different assemblies in the car and answer many questions. Good luck.
paul in CT
 
What Bob C has pictured will be needed, either way. If you have float-A-motor rear mounts, you would leave out the L shaped rubber pads. As Keith True describes no rubber pads are used between the mounts and the inside of the frame, when Float-A-motor rear mounts are used. The Float-A-motor mounts that I have seen are aluminum. One half of the mount bolts to the frame and the other half bolts to the flywheel housing. A rubber pad is held between the halves with a through bolt and nut on each side. These pads are seperate from the above pictures. There should be a spring under each side of the front motor mount yoke. Another spring is used on the through bolt of the yoke under the front cross member . I usually only tighten the castle nut under the lower yoke spring, just enough to get the cotter pin through the castle nut. If the nut is tightened more, it will usually vibrate more. If you indeed have float-A-motor mounts, check and make sure that the rear universal housing part of the FAM is in place. If the rear part of the mount was left off you will have more chatter when you release the clutch as in takeing off.
 
I put on Float-A-Motor mounts because it was so difficult to replace the original mounts/rubber pads. I'm glad I did now. It smoothed out considerably and they are adjustable.
 
Here is a picture of an original rear motor mount. If this is the style that you have, you will need to use the L shaped pads between the rear mount and the frame. This is really the best rear motor mount, but the hardest to install. You will need a frame spreader to install this style mount because it is a very tight fit. I have used a 4 ton porta-power jack bofore I got my frame spreader. The original style rear mount gives another solid crossmember at the flywheel housing and gives more stability to the whole drivetrain.
2043380-T600450.jpg
 
Here is a better picture. This is a double A but the same setup. With the fenders and splash aprons removed, this gives a better view of the whole original style rear mount. The flat rubber pad goes under the outer metal plate with three bolts on the outer side of the frame. I hope this helps.
2177472-S800x400.0.jpg
 
JBohannon said:
Ok I think I will try to improve the vibration a little bit. I think I will repair the front mount since the rubber seems bad in the center bolt and I am missing the 2 side springs. And I will put 1'/4" rubber between frame and flywheel housing. Do you all think that will help some. Joe B.
Click to expand...

A proper front mount has no rubber. The center stud fits through a curved flat spring and is supported on top of the cross member by two springs that fit in the mount and upon two dimples in the flat spring. The lower side of the center stud is supported by a spring that rests against a flat washer on the cross member, with a castellated nut holding the spring in place. Studies by Model A Times and others have shown that all alternative front mounts increased vibration over the original.

see Vince's page on the A engine front mount here:
http://www.fordgarage.com/pages/afrontmounts.htm

If the correct mounts do not help, then the vibration is probably from an unbalanced engine, loose center main, worn U joint, unbalanced flywheel or other loose or unbalanced situation. An original Model A was smooth, with only a little vibration typical of 4 banger engine design prior to the development of internal counter rotating balance shafts.

given your description of the mounting you have now, new rubber in the rear and the correct front should make some noticeable difference.
 
MYTHS, MYTHS, MYTHS! The new Model A engine was NOT smooooth, like Hmmmm! Yes, it was probably smoother than an old worn out motor that has been "AROUND THE HORN." Think about it.............It's impossible!
Bill W. (Myth Buster, Ghost Chaser & Discussion Stirrer)
 
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