Spring to air ride suspension conversion - pete379

These were undrilled rails to start. Every hole in them I started with a 3/8" bit, then ran a tapered reamer through with a 1/2" heavy duty Makita drill. Might have taken 2 hours max to do all the holes in the picture on both rails like that.

 

Mag drill with annular cutters is the way to go. Easy and quick.

 

What is the reason peterbilt uses class 10.9 bolts which are closer to grade 5 bolt?
Instead of using grade 8 bolts?
You would think you would want to use strongest bolts possible on the frame.
Must be a reason for it. Anyone explain this?

 

I'm by far no expert BUT Grade 8 doesn't stretch but will brake or shear easier than a grade 5 that will stretch but not shear as easy. Kinda like glass is strong and wont bend but breaks and wood is soft and bends.

 

Remember, before drilling, measure twice. Otherwise that truck will dog track like an old hound.

 

As a farm boy who has replaced many many shear bolts in augers and other PTO driven devices I disagree with that statement. It's been my rxexperien that a grade 8 will hold a much higher load than a grade 5 before shearing. Ever used a grade 3 bolt as a shear bolts? Forget about it, won't hold for crap.

 

Class 10.9 = grade 8
Class 8.8 = grade 5

 

I th

tgats what I thought. ####### at bolt place wanted to argue with me and then I believed him. Thanks