[DeTomaso] Shift Happens - Broken Motor Mount Bolt

[Larry Stock]

Mike not to bore everyone with a bunch of engineering specifications for
each comparative bolt design, you all can read about all these details
here at 
http://tinelok.com/grade-5-vs-grade-8-fasteners/
The conclusion basically sums it up;
Getting back to the original question, “which fastener grade should I
use?” We hope it’s very clear by now that grade 8 fasteners are far
superior to grade 5 fasteners. If this is so, then why do the automotive
manufacturers use some grade 5 fasteners? The automotive OEM’s use what it
needs to be safe and nothing more since there is a difference in cost
between grade 5 and grade 8 (or metric 8.8 and 10.9). Since the OEM’s
manufacture millions of vehicles each year, the difference in a few cents
per fastener adds up to a lot for them.

Larry Stock



On 5/14/18, 7:37 PM, "Mike Drew" <MikeLDrew at aol.com> wrote:

>Larry,
>
>Grade 8 bolts are stronger in tension and weaker in shear. They are more
>brittle, and they break when Grade 5 bolts bend.
>
>The fix is to use Grade 5 bolts―as originally installed (for a reason).
>The engine subjects the bolts to shear loading and Grade 8 bolts will
>snap when Grade 5 bolts distort. A distorted bolt is still doing its job
>after a broken bolt isn’t!  (Thats also why A-arm bolts are Grade 5
>instead of Grade 8).
>
>There are lots of other applications where Grade 8 bolts are appropriate.
> It depends on the nature of the job they are being asked to do. But
>neither Grade 5 or 8 bolts are ‘better’. They are instead ‘different’.
>
>The Ford engineer guys are no dummies.
>
>Scott―you should be able to support the engine from below (or suspend it
>from above), then unbolt the bottom half of the engine mount, remove the
>through bolt, and withdraw it. Then you can remove the other upper mount
>bolt (hope it isn’t broken too) then remove the upper mount. Then you can
>determine if you can extract the broken bolt with an EZ-out. Frame rails
>might make access difficult, so you may have to unbolt the other side
>mount and raise it up with a hoist to get better access.
>
>If the bolt is broken off inside the block and the EZ-out doesn’t work,
>you may need to take the block to a shop that can do EDM, Electro
>Discharge Machining, and have it zapped out. Or perhaps a machinist can
>extract it for you. Dismantling the engine might be part of either of
>those operations however....
>
>Mike
>
>Sent from my iPad
>
>> On May 14, 2018, at 11:04, Larry Stock <larrys at panteraparts.com> wrote:
>> 
>> There should be 2 bolts Scott, so I assume you sheared the other one
>>also.
>> Since you so good with that camera, shoot me a photo of the other side
>>as
>> well, I¹d like to see what the bolt heads indicate what grade of bolts
>>you
>> had in there. Factory came with grade 5, and after Radial tires were
>> invented and installed the true nature of the difference of a monocoque
>>vs
>> Unibody became evident with the shearing of the grade 5 bolts with the
>> engine being engineered as stressed member of the chassis. The fix has
>> been to use grade 8 or higher to keep that engine as a stressed member
>> brace of the chassis design. More Grip, more stress.
>> 
>> Larry
>> 
>> On 5/14/18, 10:47 AM, "DeTomaso on behalf of Scott Mead Photography"
>> <detomaso-bounces at server.detomasolist.com on behalf of
>> scott at scottmeadphotography.com> wrote:
>> 
>>> Hi Everyone -
>>> 
>>> 
>>> I was under the car this weekend, diagnosing my paperweight of an A/C
>>> system, when I noticed something a little unnerving: The right-front
>>> motor mount bolt had sheared off in the block, and the motor had
>>> shifted. With the hole in the motor mount no longer lining up with bolt
>>> remnants, there's no way I can "easy out" the bolt. Aside from pulling
>>> the engine/ZF, can I take out the other bolt, loosen the bolts on the
>>> other side and (using a block of wood under the oil pan), jack the
>>> engine up a bit to re-align or remove the motor mount to extract the
>>> bolt? Are there any other options I haven't thought of?
>>> 
>>> 
>>> Thanks,
>>> 
>>> 
>>> Scott (caretaker of 5638)
>>> 
>>> 
>>> 
>>> SMP-Slogo
>>> 
>>> PO Box 1190
>>> 
>>> Lake Arrowhead, CA 92352
>>> 
>>> T: 626-660-8075
>>> 
>>> E: scott at scottmeadphotography.com
>>> 
>>> W: www.scottmeadphotography.com
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