Frame Repair

[mudtoy67]

The years have finally taken a toll on my truck's frame, producing a 3" long crack behind the driver's radius arm drop bracket.

http://img372.imageshack.us/img372/731/dscn05758yn.jpg

What's the proper way to fix this? From what I've understood I need to drill a hole at the end of the crack to relieve the stress there and keep the crack from continuing. Also I need to grind a groove along the crack to give the weld something to flow into. But should I do this on both sides or just the outside? The crack is very close to the body mount rivets so I dont think I could plate the inside of the frame, but I do think I can box the frame to help strengthen the frame in the in the drop bracket area. Any other ideas?

[KrazyKarl02]

Proper way to fix it, get a new frame

Pilot hole drilling will stop the crack... To weld it you need to gouge it or grind it till there is no trace of the crack, then weld it. After welding I would stress relieve by letting the metal cool very slowly, maybe some sort of thermal wrap or slow cool with a torch

That being said, after doing all that I would scab a piece of plate over it, for added strength, my experience with cracks is they just keep coming back...

[robertf03]

don't scrap it, j-b weld it

[AggieTJ2007]

it looks like if you welded a brace or a gusset in there it would help alot

[CheapJeep]

nice crack. :gigem:

[sasquatch]

i guess mid 90s f-150 frames had some problems. both your frame and seths are cracking. drilling the crack and grinding a small gap or bevel seems like the way to fix it

[Seth]

don't forget tate

[sasquatch]

i didnt know tates is cracked too. that sucks

[william_ace]

tates is not anymore, thats why he did a frame off. so he could get a new frame...

[fbronco86]

Proper way to fix it, get a new frame

Pilot hole drilling will stop the crack... To weld it you need to gouge it or grind it till there is no trace of the crack, then weld it. After welding I would stress relieve by letting the metal cool very slowly, maybe some sort of thermal wrap or slow cool with a torch

That being said, after doing all that I would scab a piece of plate over it, for added strength, my experience with cracks is they just keep coming back...

really after welding you should probably heat the area up with a torch and let the whole area cool down. I would also ping it with a ballpin hammer to relieve stress.

[mudtoy67]

What's the deal with stress relieving using the ball-peen hammer? Do I do it when the area is heated or when it's cold? And any special way of doing it or just smack it a bunch of times?

Karl-I had thought about trying to do a little heat treat like you are talking about, but i'm not sure how I could insulate that part of the frame to slow the cooling.


it looks like if you welded a brace or a gusset in there it would help alot

I'm planning on boxing the frame. I'm also thinking about making a brace that connects the back of the two radius arms together at the retaining nut.

[eight]

Don't worry about this heating and shot peening crap. Just drill little stop holes past where you think the crack ends, grind into the crack, and put a good weld into it. You can preheat if you'd like, that's more improtant than trying to slow the cooling, because by preheating you greatly slow the cooling of the weld because it is not cooled as quickly by the surrounding cold metal. And don't weld it too hot. If you're not comfortable welding it, I'll weld it for you if you turn the truck over.

[DRAGOONRANCH]

Kopeki hit on the most important thing of this project. If you are not comfortable weldiing it, get some one that is. It takes better than average skill to get this right. Numerous frames, various pieces of farm equipment, and plenty of structural welding have taught me that you have to do it right. If not, it will crack again, or will pass the stress on elsewhere and start another one. Good luck with it :beer:

[BMFScout]

BDR, I'd let a professional do it... :flipoff2:

[Doug Krebs]

I saw CDR on the motorcycle today. She was behind me at a redlight and I saw a yellow windshield sticker in my mirror. Turned around and waved, at first she didn't know who I was at and looked behind her. I waved again and then she looked at me like i was a registered sex offender. After a couple seconds she realized it was my goofy ass.

[mudtoy67]

I'm comfortable with welding...i did plenty of it when I had a job :D

I'm just now learning the techniques involved in heat treating and stress relieving so I'm not yet that familiar with them. I figure as long as I do some stress relief and reinforce the frame it should be fine. Nothing is going to 100% keep this problem from coming back. It's a 21 year old frame and there is a lot of stress applied to the frame from that radius arm drop bracket. As long as the truck stays in one piece another couple years I'll be happy.

[Doug Krebs]

123

Testing... Testing...

[mudtoy67]

Testing... Testing...

Check now :)

[mudtoy67]

BDR, I'd let a professional do it... :flipoff2:

You make me a sad panda...

[jerryg79]

I'm comfortable with welding...i did plenty of it when I had a job :D

I'm just now learning the techniques involved in heat treating and stress relieving so I'm not yet that familiar with them. I figure as long as I do some stress relief and reinforce the frame it should be fine. Nothing is going to 100% keep this problem from coming back. It's a 21 year old frame and there is a lot of stress applied to the frame from that radius arm drop bracket. As long as the truck stays in one piece another couple years I'll be happy.

21 years old? What do you have that is an 85?

[CheapJeep]

21 years old? What do you have that is an 85?
Exactly what I was thinking.

[mudtoy67]

21 years old? What do you have that is an 85?

Sorry, I just got out of a fluid dynamics midterm and my brain is fryed.

I must have used

frame age=(Pa/gamma)+Za+(Va^2/2g)=21

It's 11 years old :)

[Seth]

but the design is 21 years old....er somethin.......

[Shaggy]

cracked frames suck... that is all

[Graystroke]

if you want to shot peen after your done you can get an air hammer attachement like I have that will do it to it a million times by just pullling the trigger on the air hammer. pre-heat is the most important like everyone said. shot peening would be a good idea to relieve stress iwhere the weld meets the parent material...what is that, the fillet?

[mudtoy67]

Luis, Jose, and I fixed it this afternoon. Once removing the radius arm drop bracket and cleaning away some of the rust, we found the crack was actually two cracks which joined, seperated, and then made a circle joining again:eek: (see pic). I used a die grinder to cut a nice groove along the bottom side, and then the portion that was behind the body mount I used a drill with a 3/16" bit. First I drilled a through hole at the end of the crack, then drilled multiple holes about half deep along the rest of the crack where I couldn't grind a groove. We then heated the area, about 3/4" on each side of the crack and I welded it up. Before it had a chance to cool I heated the area again till it was lightly glowing and let it cool. I didn't have time to box the frame, but I think it should hold for now, I don't beat on my truck like I used to.

[bburris]

No more trips to Shiloh for the F150? :confused:

[mudtoy67]

Not till I get another DD.......then the interior says bubye, the welder come out, and it's on! :gigem: