Float-A-Motor Problem

[Lona]

Our '31 roadster had a vibration problem I felt was related to the motor mounts. It has FAM mounts which were installed over 20 yrs ago and the rubber was hard. Removing the old doughnuts, I found the top ones to be the same thickness as the replacements but the bottom ones were only half as thick. Saw marks on the lowers indicated they had been cut down but I can't understand why because there was no problem installing the new thick ones.

In order to get the hand crank to engage, I had to pull down on the front mount to the point the yolke springs are almost completely compressed and the nut on the center bolt below the cross member is about 1/2" above the cotter pin hole. There was a noticable reduction in vibration after a test drive and I am pleased with the results.

However, something does not seem right with this picture. I am concerned about the alignment of the engine and drive train and the possible stress on the bell housing.

Has anyone else had this problem and, if so, how was it corrected? Should I be concerned or just leave it how it is?

Glen

[Mitch//pa]

the FAM mounts have a top and a bottom... if installed upside down that will cause the crank hole to not align

[Ray in La Mesa]

Do you have the rear yolk mount over the joint housing? This helps considerably in getting it all to fit right. It is part of the FAM kit, if not you could find one here or at a swap meet.

[Del in NE Ohio]

I see a lot of FAM's with rear mounts installed up-side down. Some earlier versions were not marked as to which side faces up. Try this. Look at the upper bolt that attached the FAM bracket to the flywheel housing. If you cannot get your finger tip between the head of the bolt and the bracket, it is probably upside down. Check the lower bolt. If you CAN get your finger tip between the bolt head and the FAM bracket, it is upside down.

[Lona]

Originally Posted by Del in NE Ohio

I see a lot of FAM's with rear mounts installed up-side down. Some earlier versions were not marked as to which side faces up. Try this. Look at the upper bolt that attached the FAM bracket to the flywheel housing. If you cannot get your finger tip between the head of the bolt and the bracket, it is probably upside down. Check the lower bolt. If you CAN get your finger tip between the bolt head and the FAM bracket, it is upside down.

Thanks for the replies. I did not replace the original FAM mounts...just changed the rubber doughnuts and installed the yolke at the transmission that was missing when I bought the car. This is not saying the last owner might have installed the FAM mounts upside down. However, the hand crank fit ok before I changed the doughnuts.
We are presently snowed in at Richmond and won't be able to get to the car in Gloucester until the weekend. Good point on how to check if the mounts are installed wrong and I'll investigate when I get to the car.

Glen

[stewwolfe]

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Glen, give Dennis Stone a call (if you don't have his number call me and I'll give it to you). It sounds like you both might have similar problems. Stew

[Lona]

Originally Posted by Lona

Our '31 roadster had a vibration problem I felt was related to the motor mounts. It has FAM mounts which were installed over 20 yrs ago and the rubber was hard. Removing the old doughnuts, I found the top ones to be the same thickness as the replacements but the bottom ones were only half as thick. Saw marks on the lowers indicated they had been cut down but I can't understand why because there was no problem installing the new thick ones.

In order to get the hand crank to engage, I had to pull down on the front mount to the point the yolke springs are almost completely compressed and the nut on the center bolt below the cross member is about 1/2" above the cotter pin hole. There was a noticable reduction in vibration after a test drive and I am pleased with the results.

However, something does not seem right with this picture. I am concerned about the alignment of the engine and drive train and the possible stress on the bell housing.

Has anyone else had this problem and, if so, how was it corrected? Should I be concerned or just leave it how it is?

Glen

Well, with all the snow and cold weather, I finally got back to where my roadster is garaged to check the FAM mounts. I had hoped the mounts were installed upside down by the previous owner but they were not. So, no solution yet. While hard to measure, the top of the head slants upward to the radiator about 5 degrees when the frame is level. Is this normal? Should the engine be level with the frame?
I'm still stumped as to why the front mounts had to be tightened to where the mount springs are almost fully compressed in order to just get the hand crank to engage and am concerned about possible strain on the drive train.
Anybody have ideas on this?
Glen

[Del in NE Ohio]

A quick way to check your rear engine height. Park on level surface. Using a yardstick/tape measure/whatever and measure the from the ground up to the upper inside surface of the frame rail. (where the orig motor mount would have been positioned). Then measure from the top of the machined mounting surface of the flywheel housing ( this is the point where the flywheel housing would have rested on the orig motor mount) down to the ground. Compare the two measurements. Often, the rubber biscuits are compressed too much, making the rear of the motor too low and in turn raising the front of the engine somewhat. Also, over-compressing the rubber biscuits can lessen the vibration absorption properties of the rubber.

[Lona]

Originally Posted by Del in NE Ohio

A quick way to check your rear engine height. Park on level surface. Using a yardstick/tape measure/whatever and measure the from the ground up to the upper inside surface of the frame rail. (where the orig motor mount would have been positioned). Then measure from the top of the machined mounting surface of the flywheel housing ( this is the point where the flywheel housing would have rested on the orig motor mount) down to the ground. Compare the two measurements. Often, the rubber biscuits are compressed too much, making the rear of the motor too low and in turn raising the front of the engine somewhat. Also, over-compressing the rubber biscuits can lessen the vibration absorption properties of the rubber.

Del,
Good point about taking measurements to determine what the position of the motor should be when it had the original mounts. Will check that tomorrow.

However, the old FAM lower rubber doughnuts were cut down to half the thickness of the new ones I installed which would have lowered the motor at the rear even more than it is now yet the hand crank fit ok with the thinner doughnuts.
Glen

[modelAtony]

Lona. On a degree is should be 3 degrees, lower to the back. have fun modelAtony tony white Lafayette, LA

[hardtimes]

Hey Lona,
I also have FAMs to many years. About 3 degree engine tilt(front to back) it about all should be. 5 degrees seems like what would occur if someone cut the rubber insulators (donuts) as you've stated has been done. And, yeah that would seem to necessitate cranking down on the front mount to somewhat compensate. I'd reinstall the new proper thickness donuts and I think that you will see the difference. BTW, it's good that you installed the other part of the mount on the trans at the front of center cross member. Without this necessary mount, I can see where someone who didn't know better...cut into the lower FAM donut. I've never had a problem with properly installed/maintained FAM mounts.
BTW...I have heard/read that there are BETTER rubber donuts than the ones that model A suppliers have, i.e.- better/harder/firmer donuts. I seem to remember that maybe the front V8 flathead engine mount donuts will work. Don't know as haven't tried them yet ?

[Lona]

Del, Model A Tony, Hardtimes,

Thanks for the input. Today I took a more accurate measurement of the motor incline, using several points on the motor and also allowing for the average readings of the frame. The average incline seems to be between about 2.5 and 3 degrees instead of the five degrees I first measured somewhat inaccurately. This would indicate the motor is just slightly lower in the front than it should be but if I raise any higher in the front, the hand crank won't fit.

I also measured the distance from the floor to the top inside of the frame rail and from the floor to the machined surface for the mount on the bell housing. These measurements are within 1/16" of each other indicating the FAM's are installed very close to where they should be.

The old lower doughnuts I replaced were cut down to a full 1/2" less than the thickness of the replacements so the back of the motor was sitting 1/2" lower than it is now yet the hand crank fit ok. I did not change the old FAM mounts, only the doughnuts and the old mounts are not installed upside down.

I'm still in the dark as to why the hand crank just about fits into the crank nut, especially after the replacement doughnuts raised the rear of the motor 1/2" and I had to tighten the front mount to where the springs are almost fully compressed. The crank works and I am ok leaving things as they are provided the opinions of the Model A gurus say not to worry about if there will be no stress or damage to the drive train.

Anyone out there have this problem and found the cause and a fix?

Glen

[Mitch//pa]

how did you determine that the rear mounts were not on upside down??

[Bob C]

In the drawing on page 253 of the A.G. McMillan book it
shows the engine at a 3 degree 20 min 52 second angle.

Bob

[Lona]

Originally Posted by Mitch//pa

how did you determine that the rear mounts were not on upside down??

Mitch,
See Del's post No 4 above which I did. Also checked the new FAM mount I didn't use which has "TOP" stamped in the casting. The old one not removed is in the same position.
Glen

[Mitch//pa]

Originally Posted by Lona

Mitch,
See Del's post No 4 above which I did. Also checked the new FAM mount I didn't use which has "TOP" stamped in the casting. The old one not removed is in the same position.
Glen

okay good... yes i have seen many early ones not stamped ....

just checking...

[bettlesr]

Maybe check to see if it has the after market front mounts with the rubber cones in them as they make the front of the engine sit to high.

[Lona]

Bettiesr,

Seems my front mount is not original but is the one with a yolk that attaches to the timing gear housing. It has two springs about 6" apart that rest on the front crossmember and a center bolt that goes through the member with a cotter pin nut on the bottom. I have read several posts saying you should tighten the nut just enough to get the cotter in but if I do that, the engine is too high and the crank won't line up with the crank nut. To line it up, I had to tighten the yolk nut to where the springs were almost fully compressed and the nut was about 1/2" above the bolt cotter pin hole.

Still no answer or solution to the problem. I must be doing something wrong but don't know what.
Glen

[Lona]

Originally Posted by bettlesr

Maybe check to see if it has the after market front mounts with the rubber cones in them as they make the front of the engine sit to high.

By the way, wife & I grew up in West Orange &got married at Florham Park country club almost 52 yrs ago.
Glen

[Bob C]

See the link to Marco's site to make sure your springs
are not to tall and you have all the right parts.
http://www.abarnyard.com/workshop/mount.htm

Bob

[Tom Wesenberg]

Your front mount is the original style. Some of the repro springs were too stiff and made the front of the engine set too high. I've bought springs fron Bert's, Bratton's, and Snyder's and they've worked fine. You might want the 4 rear mount bolts loose while you adjust the front.

[Lona]

Originally Posted by Bob C

See the link to Marco's site to make sure your springs
are not to tall and you have all the right parts.
http://www.abarnyard.com/workshop/mount.htm

Bob

Bob & Tom,
Thanks for your input and link to Marco's site showing the diagram of the dimensions and parts I should have for the front mount. I didn't think about a problem with the front mount because the crank fit fine before changing the rear FAM doughnuts. Also didn't know this was the original type front mount.

Springs that are too tall or missing parts could be the problem. The previous owner altered the rear FAM doughnuts and may have incorrectly played with the front mount as well. I will check the springs now mounted in the car when I'm able to get back to where the car is stored early next week. It's frustrating to have a project interrupted like this because of having to be away from home and I hope you all will be patient if you don't hear from me immediately regarding your suggestions. I will post my findings as soon as I can.

Thanks, Glen

[Lona]

Finally got back to work on the FAM problem. See photo. The old parts are in the background & the new parts up front. Several of you were correct, the old springs are 1/2" longer than the new ones and were probably 3/4" bigger when they were new. And they do have rubber inside the springs.
How do the new parts install? Per Marco's original Ford diagram, it looks like the flat composition washer goes on the yolk stud first, then the 5" long arched steel spring with the two new coil springs. The brass bushing installs from below the cross member along with the smaller spring, nut and cotter pin. Is this correct? I'll get the mount installed soon as someone can confirm the assembly sequence.
Hopefully, this will allow the engine to sit lower and allow the crank handle to properly engage.

Glen

[Bob C]

The brass bushing was not used after Jan 29, it was replaced with
a flat washer A-22323. Bratton's catalog says the washer was 3/16"
I can not find the washer listed in any of the Ford parts books but
it is shown in Marco's drawing.

Bob

[Lona]

Bob,
Thanks for responding quickly. After my last post, I went to Snyder's catalog and found a diagram of how things go together. They show the parts sequence as I described, including the brass bushing which they note is for '28 thru '31. The washer that goes on the yoke first in my repair kit is 1/8". Will install and see how things work out.

Glen

[Lona]

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Bob,
Thanks for responding quickly. After my last post, I went to Snyder's catalog and found a diagram of how things go together. They show the parts sequence as I described, including the brass bushing which they note is for '28 thru '31. The washer that goes on the yoke first in my repair kit is 1/8". Will install and see how things work out.

Glen

[Lona]

Thanks to all who responded with suggestions on my front mount problem. Got everything together today and did a road test. The vibration I had is considerably less now and I can actually clearly see cars in the rear view mirror where before they were just a blur.

Turns out the front mount problem was two problems instead of one. First, the springs I took off were too long which required tightening the yoke center nut to the point where the springs were fully compressed, thus no vibration isolation. Second, apparently the hole in the cross member had worn too large so the previous owner welded a 1/4" plate on the top of the cross member and drilled a new yoke hole in that plate. This made the excessive elevation of the motor even worse. I was able to install a new front mount spring kit but could not install the brass bushing above the lower spring because the welded plate interfered with the bushing going up into the cross member. However, everything else is installed and working fine.
Again, thanks to all who replied with advice.

Glen