I just spent the whole day grinding and drilling off all of the old spring hangers off of the chassis. I am going IFS + IRS, after getting them all off the chassis now looks a lot like swiss cheese in a number of places.

So what have others done, just left them, or welded them over?

It looks like a lot of work to plug all all of them...

I am boxing the front and rear sections but did not intend to box all the way through.

Thanks
Lee

 

It is my understanding that with both IFS and IRS you want a very stiff frame for the independent suspensions to work properly. Filling extra holes is an appearance feature so it is mainly up to you. Don' forget to add weld nuts inside the boxed areas for items like stabilizer bars, etc. On my 56BW with the Corvette C4 IFS and IRS I have a fully boxed frame and am considering removing two crossmembers and adding a tubular x-member to make it more rigid.

 

I used a hole saw and cut out pieces to fit into the holes in the frame, and welded them in, these holes really will not be seen but esthetically the rails look better with the holes filled.

 

Lee -

Ditto what LEckart said. The holes do not degrade the structural integrity appreciably. If you want to lay mirrors around it when you park it, fill them.

Boxing the entire frame is not appreciably more work than boxing some of it, but the stiffness of the overall structure goes WAY UP when the whole thing is boxed. Box it all! With IFS and IRS, you'll be glad you did. The problem with boxing some of the frame actually creates a problem. While the boxed area is stiffer for obvious reasons, the unstiffened sections wind up seeing more stress and flex more than they did before. In fact, the unboxed areas wind up seeing all the stress (twist) that the entire frame handled before. That can lead to cracks in the frame rail where the boxing ends.

(My Engineering 101 professor would be proud).

 

I boxed back to the front Cab mounts.... slicked all that up pretty since the whole front tilts.... left all the other 763 holes just where they are...no mirrors under mine..

john

 

Mine is boxed from front cross member to the rear, left all the holes. If your going to fill the holes, I'd leave a couple on the bottom for drainage incase any moisture develops inside.

 

The steel used in these frames doesn't take to a lot of welding. Without good heat control you can make it brittle.

 

I painted my frame pretty nice but did not feel any holes.After my truck is finished I hope to never see the underside of it again.HA HA

 

Lee, These photos show some of the boxing done on 53' that has a Corvette IFS and IRS. On a Vette leaving "flex" in the frame would sorta Kinda defeat the purpose of using a Vette Suspension. See the Front Clip in my gallery under 55 F100 Stock Seat Restomod





Donald in TN

 

Thanks to all for the replies,

I dont intend laying mirrors under it when its done. It will be used, not become a trailer queen.

I will have a go at boxing the front and see how it goes. If it goes well, I will probably have a go at the whole thing....

I was wondering about the stresses on the unboxed area myself. I have to admit that I have never worked on a truck that sat on a simple rivetted u section frame before. I couldnt beleive it when I first saw it.

I am used to 4x4 Land Rover chassis' that come as a solid box frame as standard.

Thanks
Lee

 

Lee-
When boxing your frame be sure to weld small sections at a time, skipping around, just as if welding sheetmetal panels. You don't want to heat the metal to the pointing of warping or twisting the rails.

 

trucks that are built for heavy duty use are usually u-section frames to allow flex, so that it will not crack when a whole load of stone is dumped in the back and such it doesnt snap. that is why even on the 2006 super duty its not a fully boxed frame. The boxed frame is used in say, the new f150, to decrease flex in frame to allow the suspension to do its thing, and decrease creaking and groaning of bed and cab. each has its own purpose.

 

Filling the holes in my frame is still on my "to do" list and will probably stay there....

Vern

 

of course.... now that I think about it ?????

I might fill all mine in ..... then drill them out and fill them in with a different wire !!!!! yea, that's the ticket...

I'm a sick puppy

Later
John

 

I left the holes in my frame. Maybe better aerodynamics? To quote Homer Simpson, I'll call them "speed holes".