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Bolt hole size question

cgalpha08

"Like Nothing Else"
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3,584
Location
Indianapolis, IN
All, I'm looking for the correct size bolts that go into the holes into the attached photo. I believe these are the holes where the added crash/impact bar bolted into in the 08+ years.

The bigger hole i think is either a M10x1.5 or a 3/8 -16tpi, I had a 3/8 laying around and it went in but wasn't happy.

If anyone knows the sizes that would be much appreciated. Thanks.
1be24efd630380e65428a4a23981d8f6.jpg


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Alpha X

Well-Known Member
Messages
409
Location
The Motor City
It's highly unlikely a standard thread, and it probably isn't a metric fine thread. That leaves a few metric choices in coarse thread. If the bigger hole is a M10x1.5, the smaller hole looks like a M6x1.0.
 

cgalpha08

"Like Nothing Else"
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3,584
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Indianapolis, IN
Which is why it makes me think the larger one is M10×1.5, it's close in similarity to the 3/8-16tpi.

I'll pick up a handful of bolts in various sizes and see which one fits best lol

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Last edited:

Alpha X

Well-Known Member
Messages
409
Location
The Motor City
AFAIK, GM hasn't used SAE threaded bolts since the 80's ha ha....

Fun fact... and this is a tangent from this thread. There's one component that is still fastened with a SAE fastener. I believe this is true with GM, Ford, & Toyota. This component is used multiple times per vehicle.
 

Korby7

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395
Location
Utah
Big ones are M10-1.5 and smaller are M6-1.0. If yours are like mine it'd be good to run a tap through the M6s.
 

cgalpha08

"Like Nothing Else"
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3,584
Location
Indianapolis, IN
Any time a bolt doesn't want to go in it's either the wrong size or it's really dirty/rusty.

It's definitely metric. Those are for the impact bar for sure. What are you trying to bolt onto there?

I gotcha, yea i picked up some metric ones to test fit, for a few bucks i figured why not.

As to why, I'm going to fab up a cross-member and bolt it into those holes. Reason being: Since i'm solid axle swapped, there really isn't a cross-member from the trans forward. The Thorparts bumper kinda acts like one but i want another for added rigidity. Mainly this is due to the trans fluid line coming out of the radiator when i was on the trail a couple of weeks ago. I've got a few theories as to why it happened. 1. The frame twist and flex somehow worked the clip loose. 2. the rubber flap that I have yet to cut off, knocked the clip loose somehow in a water or mud hole possibly. Or 3. it was already loose and the trail riding just sealed the deal and popped it out.
Either way I have no idea how it happened, but I want to make sure it doesn't happen again lol


Big ones are M10-1.5 and smaller are M6-1.0. If yours are like mine it'd be good to run a tap through the M6s.

Thank you! I did happen to buy both of those in my "test bolt" buy ha. I have a M10-1.5 tap already, might have to get the M6-1.0 depending on how nasty the threads are.
 

scoreh3

Well-Known Member
Messages
1,024
Location
SoCal
Fun fact... and this is a tangent from this thread. There's one component that is still fastened with a SAE fastener. I believe this is true with GM, Ford, & Toyota. This component is used multiple times per vehicle.

I say it’s the muffler bearing retaining nut .
 

Alpha X

Well-Known Member
Messages
409
Location
The Motor City
Fun fact... and this is a tangent from this thread. There's one component that is still fastened with a SAE fastener. I believe this is true with GM, Ford, & Toyota. This component is used multiple times per vehicle.

.... Seatbelt Retractors. I'm not sure why, but I'm assuming it's because it's been extensively tested with a SAE fastener, and they aren't going to change now. If I recall correctly, GM, Ford, & Toyota are held with a 7/16-20, possibly other auto manufacturers. This was true 5 years ago, and I believe it is still true today. A buddy of mine said new GM full size trucks still use this fastener.
 
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