as I posted before I am changing the power stering setup on my 74' f250. here is my question A friend of mine said that I should not weld the tubing and the plate to the frame. He said nothin should be welded to the frame because the frame is designed to flex. Has anybody know of this. I did not think it would be a problem welding in the steel. has anybody had problems after they did this up grade? thanks

 

your truck 2wd, or 4x4?? welding to the frame is generally not a good idea.... but in some cases it is nessary... what do you need to weld to the frame??

 

the flatbed on my 77 wasn't secured very well at all and I considered just welding it to the frame. But , I decided to weld a piece of 3/8 " by 5 " plate to the flatbed and bolt that too the frame. All metal to metal connections made at the factory are done with Rivets...not welded so there is your answer i suppose.....fd

 

I have never had a problem welding on my or other people's frames. I know a lot of people and shops that do. If you are competent and know what you are doing, then it's ok. I would assume frames are riveted at the factory because its quicker, cheaper and easier, not because its unsafe. Even so, alot of the chevy pickup frame is welded.

 

You can drill holes into the frame to attach brackets and other items. Just don't drill into the flange area. Welding the frames of trucks isn't considered a good idea because of the heat treated steel in them. Welding will weaken the strength of any and all forms of heat treated steel.
Having said that don't drill too agressively and use a spray lube as a coolant as the heat from drilling can also weaken heat treated steel.

 

if you do weld it in do it along the frame. never across the frame. the cross members below your engine is probably welded in. you also want to make the welds in short stiches & then let it cool. when i did this conversion on my truck i boxed the frame with a piece of channel iron & some flat plate. everything was bolted in at first. i then made four small welds on all four corners of the channel to keep things in place.

 

I have never had a problem welding on my or other people's frames. I know a lot of people and shops that do. If you are competent and know what you are doing, then it's ok. I would assume frames are riveted at the factory because its quicker, cheaper and easier, not because its unsafe

actually, it is unsafe, it's not always cheaper, or faster.

welding on a frame depends on what it is, how the frame is made, and what it is you are trying to mount.

Frames are ment to fle atleast in 73-79 ford trucks they are). if you weld a xmemeber in, it will crack, it's just a matter of when. the reason the factory uses rivits, is that they will alowe some movement between the frame rails and the xmemebers (ask any compentant engineer about it, they'll spend about 2 hours explaining it to you). and is why i bolted all the xmemebers in on my 78 i rebuilt

you can weld frame rails to repair frames, or to lengthen/shorten them, but you never weld at a 90 degree angle to the rails. always at an angle(30 to 45 degrees), this keeps the stresses evened out on the rail, and will be very strong.

If you want to know how i know this, i run a machine/welding shop, and i am a certified welder. If you do choose to weld on your frame, please ask a qualitified person for thier opinion on what you are doing, and ask them for advice, even if it costs ya a few $$ it'll be worth it in a job well done.

 

Thanks for the explanation. So you're saying that if you were to shorten a framerail, you would make an angled cut on each piece that would match up when put together? I have never had any problems, but there is always room for learning and improvement. Thanks for the info.

Also, is it necessary to weld in short intervals and allow the metal to cool when welding frame type metal? And if so, how long is sufficient?

 

what I am trying to do is change the power stering set up. The 78'-79' power stearing you need to box the frame out. what will be welded is 2 pieces of 2.5'' 1/4'' wall square tubing about 7'' long on the inside, and a 1/4'' plate on the outside. Got it from the tech article. do you think this would cause problems? thanks

 

I have pictures...no naked women..just really good pics of what you are wanting too do....

send your email and i'll forward what I have.......fd

 

i assume the box your adding goes on the front part of the frame, ahead of the engine x memeber, if so it should be ok to weld there, but don't over weld it, and try not to weld very much 90 degrees to the rail.

as for shortening and joining the frame, i have made a square joint b4, with any troubles, but it was halfway between the x memebers, and was a good clean weld. on my latest project, i joined the frame right behind the front spring hangers, but the new frame i added, went ahead of the same hanger, then was cut on a 45 degree angle. all the holes in the new frame were drill to match a frame rail i had kicking around, so i bolted the old to the new with those 4 hanger bolts. then ligned everything up as close as possiable and welded it , made a good strong job, easy to keep inline, and was very solid, and safe.
pics are in my gallery for the 78 f-100 if anyone wishes to see. the whole rear section of the frame is 3/16 plate, made to match the orginal.

 

I think the guys clarified pretty well why its not good to weld on your frame, and how to keep it as cool as possible when you do. The only thing I will add is if you do weld on your frame, I would also stress relieve the welds with a ball peen.

 

With welding there is a part of the base metal right next to the actual filler metel that is called the "heat affected zone". This area has lost any of the heat treatment that was applied to the original steel. It does not do any good to keep the base metal cool etc.

Bull is right, you have to know what you are doing.

 

I will try to explain how I fit everything when I did my conversion on my 1974 high boy. I first took a piece of 1/4 plate cut to fit inside the frame. I marked an drilled holes to line up with the hole in the frame for the old steering box. I bolted the plate to the inside of the frame. The bolts were tack welded in place. I then removed the plate and welded the bolts in place permanently. I then tack welded a piece of channel iron to the flat plate. This made a box with bolts sticking out one side. The bolts matched the holes in my frame. I then bolted the box in place. The box being bolted in place allowed me to fit the steering box in place and mark the holes. I then drilled these holes. I once again removed the box. While the box was out I ground the tack weld off one side of the box. This allowed me to open the box enough to put the box side bolts in from the inside of the box. I the retack welded the box. The box was rebolted into the frame. The new steering box was bolted to the channel iron. When clearences were checked all bolts were welded in place. The box was welded permamently. All of this was then bolted in the truck. The only welding I did on the frame were four small welds on each corner of the channel iron to keep everything in place. I know it would stay in place without the welds (I tend to over do things). I hope someone understands what I just tried to explain. The channel iron and plate basically make a box with bolts sticking out both sides. One side matches the frame. The other matches the new steering box. When I remove my steering box all I have to remove is three nuts & washers.

-edited by moderator for all caps.-

 

makes sence to me. sounds like a good way of doing the change over, without welding to the frame