<VV> Re: LM mounts

Kirby Smith kirbyasmith at gwi.net
Sun Feb 26 15:14:51 EST 2006


Now that I have taken the initial steps (thanks Padgett) for 
installation, in my opinion this heavy duty mount is a good idea badly 
executed.  Beyond the barely long enough, untapered bolts used for studs 
(GM made them long and pointy for a reason), and beyond the reported 
need to drag holes and slots as required (the LM OEM unit has slots for 
the mounting bolts for a reason), and beyond my uncertainty w.r.t. the 
effect on strength of welding on the heads of the Grade 8 bolts used to 
build it, the example I got from Clarks doesn't fit the figure-8 washer, 
which does fit the two LM and one EM motor mounts in my possession.  It 
is no more likely to fit the engine cradle, which appears to have even 
less freeplay.

It would seem that a jig was not used (as it should have been) to 
establish the alignment of the bolts used for studs.

I'm not going to mill the washer and the engine cradle to accommodate 
this out-of-tolerance mount.  I'm going to ask Clarks to replace it with 
one that fits the figure-8 washer.  Then I can determine what milling is 
needed to get it to fit the frame.

kirby
66 turbo Corsa (bought new)


Padgett wrote:
> 
>> Jeff Brekke no longer have any of the mounts he was making, which I 
>> had heard were quite good?
> 
> 
> Had virtue of having replaceable inserts but I e-mailed Jeff and he did 
> not have any. When he did they were a little more expensive.
> 
> Mount had no indication of origin or any markings on it. Was part of a 
> paper tag attached but not enough to read. I had to e-mail Lon to ask 
> about them and are on page 28 of Clark's supplemental catalog.
> 
>  > couldn't use the "figure 8" washer under the two stud nuts, the studs
>  > weren't long enough
> 
> I remembered these feeling a bit a bit short but remember the factory 
> setting for the rear mount nuts (65 FSM specifications (in back) page 5) 
> is 50-60 ft-lb.
> 
> The jpg at http://padgett.ws/files/newmntstds.jpg was taken after 
> torqueing both to 50 lb-ft and then removing.  5.5 to 6 threads were 
> engaged (turns before nut fell off) on both. Nuts were replaced and 
> retorqued then one was removed again for the photo. Remember these are 
> locking nuts so taller than most. Note that the threads come to within 
> about a 1/16 of the end unlike the factory studs which have a tapered 
> guide end. I believe this is sufficient though barely and another 1/8" 
> would be nice. If someone with more expert/current knowledge has a 
> different opinion please let me know.
> 
> I know this is getting a bit AR but only took about ten minutes and it 
> is 68 degrees in the garage.
> 
> Padgett
> 
> 

> 



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