At 11:11 PM 4/16/99 -0700, Joe Curry wrote:
>
>Greg,
>I can't imagine why you would be having this problem. There is not
>supposed to be much weight or tension on that part and certainly not
>enough to cause the bolt to shear.
I agree with Joe. Greg, you _do_ know that the original air cleaner
hardware consisted of shoulder bolts with rubber washers under the heads?
They don't seem all that strong to me (as if they should be grade 5 or 8 or
anything). Heck, on my car, the rear bolt threads in the carb got 'wide'
and I ended up using a helicoil to repair the carb body because the bolt
kept falling out!.
Here's how I would attack this problem: Buy a thread repair kit (IIRC the
thread is 5/16) and go back to the original shoulder bolt type and size in
the carb. The bolts should screw TIGHT into the carb body and stop on the
shoulder (the air cleaner just sort of hangs on the bolts, thats why the
factory used the rubber washers, to fight rattles).
If you don't have the shoulder bolts anymore, you can buy them (I notice
both TRF and Victoria British list them, but they are $14 apiece!).
Or if you can't bear to part with that much cash for a 'couple of steenkin
bolts', use grade 5 hardware but make your own "shoulder" by using a piece
of pipe inside the air cleaner part of the bolt. Goal is, to have the
shoulder TIGHT against the carb, not the air cleaner housing.
>
>I would start by looking to see if something is pressing on the air
>cleaner. Perhaps the bonnet is not clearing and exerting pressure on
>it.
You said you checked that, but I know there is not too much clearance
there. Remember the motor moves on its mounts and the bonnet flexes too
while driving, so you could have interferance. I recommend sticking a
piece of clay over the air cleaner then driving on a bumpy road if you want
a true picture of dynamic clearances.
I know you can fix it,
Atwell Haines
'79 Spit
>Growe58@aol.com wrote:
>> On of the bolts holding the air cleaner to the stock carb
>> on my 78 spit keeps shearing. It is the one closest to
>> the front of the car. The first time it happened, I had to
>> drill out the remains and re-tap the hole one size larger.
>> I have been unable therefore to replace with an OEM bolt
>> and have using bolts from the local hardware store.
>>
>> I have now had four shear with the break point just below
>> the carb surface. They seem to last about 2 days. I have
>> verified that the bonnet is not making contact with the air
>> cleaner and I have (long since) removed the hot air
>> ducting and that associated weight.
>>
>> Why are these freaking bolts shearing? There's next to
>> no weight on them. Any ideas?
>>
>>>
>
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