Odd modification to motor mount bracket

Zax40

Zax40

Well-known member
These motor mount brackets have the top, motor side bolt hole notched out. You can tell this was cut out on purpose. I can't think of any reason someone would have done this. Anybody seen this before? Any theories?

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i'm guessing that someone cut them up to make it easier to get the remaining bolt started.
Seems like a poor choice.
 
The person who modified these mounts probably didn't have a standard 3/4" wrench and resorted to using an adjustable open end or maybe an old school monkey wrench.
 
I guess I may never know why it was done. The good thing is they have been replaced now and new rubber was also installed.
 
Kurt in NJ said:
Not a modification, broken, have seen similar cracks and had the piece fall out upon removal
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The missing pieces were not present, just the bolt in the hole and tightened down snug with the block doing nothing but filling a bolt hole.
 
I have seen this before. The missing material cracked-out in fatigue. My guess is that the bolts that went into the missing holes carried more load which led to an earlier fatigue life.
 
Came across the same thing years ago on a '29 AA grain truck; both side the broken pieces were still bolted tight to motor.
 
I think that’s because if you stop and think about it, how can you bolt one end of the engine to the frame securely while the front is spring loaded? The motor wants to pivot due to the movement up and down in the front but the bell housing end is bolted up tight with no way to move casing the motor mounts to crack over many years of fatigue. Seems to me if the rear mount had only one bolt per side would be a better design. Think about why bell housings crack…from taking the flex needed due to the front of the engine moving up and down. Something has to give. Just my take on it.
 
I noticed after removal the chunk missing also allowed the mount brackets to distort or sag. As in they were slightly bent downwards. I used the earlier ones to replace them and they seem a lot more beefy.
 
I have never seen this but I agree with Zax40 that it may have been a bad crack that went unnoticed and the piece fell out, but both mounts?
 
Post #7 is correct. I’ve seen a number of rear mounts broken like this. It’s best to find another one that is not broken, but be sure to check carefully for cracks. More than half of the rear motor mounts I’ve found are cracked, if not broken at that same location.
Good luck,
Jim
 
Ford had rubber cushions between the mounts and the frame, on both sides. Would this allow the engine to move up and down a little in the front so that the front spring motor mount could do it's job?
 
The rubber was sandwiched between the mounts and frame utilizing bolts and bushings to allow for some movement in the hopes that the bushings would still hold it solid. The way they formed those parts, they left relief slots in between the bolt holes. I guess they figured that that would allow for some movement without cracking. This design is better than the first design they used back in late 1927. Those early ones would crack real easy so they came up with the later types. They last fairly well but not so much if any bolts are loose.
 
I suspect the cracks occurred in the rear motor mounts from jacking up the front of the motor without loosening the rear motor mount bolts at the flywheel housing, or frame sag at the rear mounts over the years. I remember jacking up the front of the motor of my first A when I was 15 so that i could replace a broken crankshaft pulley….and I did not loosen bolts on the rear motor mounts. I’m sure others did the same.
Jim
 
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