What size are the backing plate bolts?

[Mojo88]

'03 Silverado 1500 LS - I am gonna replace the rusted backing plates. There are four big bolts holding them in, each bolt has an 18mm head. But the bolts are super-rusty and I want to order 8 new ones before I start the job. I cannot find them online for some reason. Does anyone know the size of the bolts? Pic below. Thanks!

 

 

[newdude]

11509421.  

[Mojo88]

Ahh, thanks for the part number. I was hoping to get the thread pitch and length, then I can buy at my local fastener store. That bolt (online) is nothing special, but sells for like $8 per bolt, LOL. Dang...................

[Sharpz]

4 hours ago, Mojo88 said:

Ahh, thanks for the part number. I was hoping to get the thread pitch and length, then I can buy at my local fastener store. That bolt (online) is nothing special, but sells for like $8 per bolt, LOL. Dang...................

the problem is these are specific bolts, if you know the same hardness, exact length then yeah you could just use a fastener provider, but its one of those things, do you want to risk anything with other then OEM?

[Mojo88]

23 hours ago, Sharpz said:

the problem is these are specific bolts, if you know the same hardness, exact length then yeah you could just use a fastener provider, but its one of those things, do you want to risk anything with other then OEM?

Great points, thanks, but the fastener store I go to is incredible. They have everything, and they know all about hardness and such. I am normally in the OEM camp though. Thanks again!