Make holes chassis for quarter fenders

You definitely don't want to swiss cheese the rail but extra holes won't hurt. Technically speaking if a bolted accessory is removed, the empty holes in the frame should have a bolt put back in it.

Can't remember if it was @daf105paccar or @98989 that posted a picture in the Trucking in USA vs The World thread of a log truck chassis with about a gazillion extra holes in it. Looked so strange but apparently it was factory.

 

Make sure you follow the manufacturer's recommendations for size and spacing of holes.

 

https://www.amazon.com/Blair-Equipment-11090N-Rotabroach-Cutter/dp/B000LQOCRK

Rotabroach is the fastest drill method for large diameter holes. These things put drill bits to shame on bolt holes. Low and slow drill speed and keep it lubed with a quality cutting oil.

 

It was @98989
Mercedes trucks now have a LOT off holes
But it is designed that way and i think a different steel.

Can the OP post some.pictures?
I find it hard to believe there are no holes he can use.

 

it is factory, there are 4 rows with 2inch spacing and horizontally every 2inch along almost whole frame

 

Not illegal at all.
Autocar, Diamond T, the old original Sterling (1920’s -50’s), Kenworth, Peterbilt,WesternStar and Macks that I’ve seen over the years all had the flanges drilled for crossmembers and brackets. Front and rear spring hangers were bolted or riveted on the flanges. Even fifthwheels were installed with bolts down thru the flanges up into the late 60’s. Some auxilary trans boxes were installed that way.

Flanges drilled for suspensions is still common.

The don’t drill the flange thing was put in place back in the day for the aluminum frames. Alcoa and Budd had a different spec than the steel frames. CF worked with Alcoa to develop it in the ‘40-‘42 time period. Petes first use of an aluminum frame was in ‘47or ‘48.
At one time probably 90% of trucks on the west coast had aluminum frames. Cost eventually killed that practice by the 80’s.

 

Most manufacturers of frames for these trucks use punches for the holes, not drills.

 

The top most forward bolt on the cross member in front of fifth wheel is what’s most commonly used. I just replaced one on mine. Dealer sells the tubes, they’re pretty cheap. Get some new nuts and bolts Look at any similar Truck, you’ll see.