Author Topic: motor mounts  (Read 2838 times)

EdwardGT350

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motor mounts
« on: May 28, 2020, 07:05:04 PM »
how can one determine if a motor mount is cracked or bad?
what are the signs?
will engine vibrate excessively?
how hard is it to change them?
which brand is a good quality?
are the hipo ones more robust?
im getting severe shuttering under load from a stand still and its particularly bad on an incline.
tia
1966 GT350 6s1761

gt350hr

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Re: motor mounts
« Reply #1 on: May 29, 2020, 04:43:52 PM »
   Early multi piece or later one piece mount?
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EdwardGT350

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Re: motor mounts
« Reply #2 on: May 29, 2020, 05:04:55 PM »
for april 66 build.
1966 GT350 6s1761

gt350hr

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Re: motor mounts
« Reply #3 on: June 01, 2020, 10:50:33 AM »
   Your car "should" have later "standard production" '66 mounts. They are one piece and easily inspected for cracks in the almost 3/4" thick rubber that bonds the upper and lower halves together. There are several "improved designs" but they are obvious if you are trying to keep it looking "stock" . They are not too difficult to replace. Jack stands and a floor jack are a must have.
    The shudder you describe sounds more like a clutch/flywheel issue.
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67350#1242

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Re: motor mounts
« Reply #4 on: June 01, 2020, 01:53:27 PM »
The driver's side usually the one to go first because is stretched by torque.
A good indicator with a 4spd is the shifter will tilt excessively to the right during acceleration.
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kjspeed

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Re: motor mounts
« Reply #5 on: June 01, 2020, 02:15:36 PM »
Easy to check with a friend (or if you can see your motor from the driver's seat with the hood up). Put car in drive (auto trans) and slowly press the gas pedal as you keep your foot on the brake to keep the car from moving. If the driver's side motor mount is shot you'll see the engine lift up. Put the car in reverse and repeat to check the passenger side. With a good emergency brake you can do this with a stick also. If your E brake won't hold the car, then it's a bit trickier. Either way, make sure that there's nothing in front or behind you when you do this.
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1968 Mustang GT S-code
2009 Mustang Bullitt

S7MS427

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Re: motor mounts
« Reply #6 on: June 01, 2020, 09:03:39 PM »
Put the car in reverse and repeat to check the passenger side.

I don't understand how this will check for a bad mount on the passenger side.  The engine only rotates in one direction regardless of whether the transmission is in forward, neutral, or reverse.  Am I missing something?
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SFM5S000

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Re: motor mounts
« Reply #7 on: June 01, 2020, 10:39:14 PM »
Martin,
The best stock looking OEM type to me are the Lakewood “muscle mounts”. They look like the stock ford pieces, but are interlocked.
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427hunter

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Re: motor mounts
« Reply #8 on: June 01, 2020, 11:01:34 PM »
how can one determine if a motor mount is cracked or bad?
what are the signs?
will engine vibrate excessively?
how hard is it to change them?
which brand is a good quality?
are the hipo ones more robust?
im getting severe shuttering under load from a stand still and its particularly bad on an incline.
tia



Are you sure it's not clutch chatter?
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EdwardGT350

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Re: motor mounts
« Reply #9 on: June 01, 2020, 11:37:03 PM »
same shuttering occurred before the new clutch. i thought the new clutch would solve problem.
now we think its either the flywheel or oil from a rear main seal that got onto new clutch.
advised to slip the clutch or start in 2nd gear to hopefully burn off the dried oil.
shuttering ONLY happens when starting in first gear, especially on an incline.
1966 GT350 6s1761

427hunter

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Re: motor mounts
« Reply #10 on: June 01, 2020, 11:56:40 PM »
same shuttering occurred before the new clutch. i thought the new clutch would solve problem.
now we think its either the flywheel or oil from a rear main seal that got onto new clutch.
advised to slip the clutch or start in 2nd gear to hopefully burn off the dried oil.
shuttering ONLY happens when starting in first gear, especially on an incline.



You always have to resurface the flywheel when you change the clutch, oil will not burn off - it's the clutch and flywheel not the motor mounts.
« Last Edit: June 02, 2020, 12:01:28 AM by 427hunter »
“You keep using that word, I do not think it means what you think it means”

Inigo Montoya

“This life’s hard, man, but it’s harder if you’re stupid”

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kjspeed

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Re: motor mounts
« Reply #11 on: June 02, 2020, 07:34:34 AM »
Put the car in reverse and repeat to check the passenger side.

I don't understand how this will check for a bad mount on the passenger side.  The engine only rotates in one direction regardless of whether the transmission is in forward, neutral, or reverse.  Am I missing something?

Transmission output shaft in reverse applies torque in the opposite direction. With brakes locked it will lift the passenger side if the mount is broken.

Sounds like OP's problem is clutch related though.
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1968 Mustang GT S-code
2009 Mustang Bullitt

EdwardGT350

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Re: motor mounts
« Reply #12 on: June 13, 2020, 08:25:20 PM »
where is the best place to jack up the motor to check or change the motor mounts?
can the jack be placed under the drivers side of the oil pan with a 2x4 piece of wood in between?
1966 GT350 6s1761

Jbarela

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Re: motor mounts
« Reply #13 on: June 13, 2020, 11:43:56 PM »
I am no expert but I experience the exact same thing in my mustang and in my bmw after clutch replacements.both times it was either the throw out bearing or the pilot bushing. I cant remember but I remember when the clutch was done one of those parts were not replaced and bam chatter..parts replaced and chatter was gone. I also went with needle bearing pilot bushing.