Frame cracks?
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Frame cracks?
I'm in the process of putting my 48 F-1 back together. My frame has an old crack repair on one frame rail in front of the "big" riveted crossmember behind the cab. I looked at a parts truck the other day and at first look the frame looked a lot cleaner and straighter than the one I've been planning to use. Upon closer inspection, I found that the parts truck frame was cracked in a similar way to mine but on both frame rails. Both cracks were welded and one was plated a long time ago.
My questions are:
Has anyone else experienced these cracks in the frame?
And if so, how did you go about repairing them?
I'm really thinking about taking the parts truck to see if the frame is more square than the one I have (It surely has less rust). If it is square, I was thinking about grinding out the cracks and re-welding, then plating the inside of the frame where it will be less visible. I will be installing the Jag IFS (soon, I promise!) and I may very well just box the frame back to that point. Decisions, decisions....
So what do you all think??????
My questions are:
Has anyone else experienced these cracks in the frame?
And if so, how did you go about repairing them?
I'm really thinking about taking the parts truck to see if the frame is more square than the one I have (It surely has less rust). If it is square, I was thinking about grinding out the cracks and re-welding, then plating the inside of the frame where it will be less visible. I will be installing the Jag IFS (soon, I promise!) and I may very well just box the frame back to that point. Decisions, decisions....
So what do you all think??????
Cargo Master
Joined: Apr 2005
Posts: 3,337
Likes: 165
From: Harpswell Maine
Originally Posted by badtomatoes
I'm in the process of putting my 48 F-1 back together. My frame has an old crack repair on one frame rail in front of the "big" riveted crossmember behind the cab. I looked at a parts truck the other day and at first look the frame looked a lot cleaner and straighter than the one I've been planning to use. Upon closer inspection, I found that the parts truck frame was cracked in a similar way to mine but on both frame rails. Both cracks were welded and one was plated a long time ago.
My questions are:
Has anyone else experienced these cracks in the frame?
And if so, how did you go about repairing them?
I'm really thinking about taking the parts truck to see if the frame is more square than the one I have (It surely has less rust). If it is square, I was thinking about grinding out the cracks and re-welding, then plating the inside of the frame where it will be less visible. I will be installing the Jag IFS (soon, I promise!) and I may very well just box the frame back to that point. Decisions, decisions....
So what do you all think??????
My questions are:
Has anyone else experienced these cracks in the frame?
And if so, how did you go about repairing them?
I'm really thinking about taking the parts truck to see if the frame is more square than the one I have (It surely has less rust). If it is square, I was thinking about grinding out the cracks and re-welding, then plating the inside of the frame where it will be less visible. I will be installing the Jag IFS (soon, I promise!) and I may very well just box the frame back to that point. Decisions, decisions....
So what do you all think??????
On a separate note looking at your Gallery when you get to putting the Jag under the chassis it looks to me that your stock exhausts should clear the Jag r&p. I will be interested in what you find. My Jag is in my 49 but I dealt with a cxxxy. Don't buy any headers until you get the Jag in place. A second recommendation that I would have is to consider welding the Jag crossmember in place rather than soft mounting it. I soft mounted mine and felt that I should retain the original Jag Z joint to allow motion between the suspension and the steering column. Note that if you weld in the jag there is no need for the Z joint. The Z joint is located in the Jag right down at the end of the pinion. In that the Z joint is bulkier than a u joint, it can interfere (and did with the cxxxy) with the exhaust,. I have gone thru a lot of aggrevation to locate the Z joint at the end of the steering column.
Fleet Owner
Joined: Jul 2004
Posts: 27,297
Likes: 1,059
From: NM
No cracks in mine at that location. Are the cracks in the horizontal legs, upper or lower? Or down into the web of the C-section? If in the web, that's truly serious, and is probably a sign of severe and repeated overloading.
If the crack is ground out and welded with a full-penetration weld, by a qualified welder, I would resist adding plates. It just makes the frame stiff in that location (only), creating an opportunity for stress to attack the frame at the ends of the plate. It may be desirable to stress relieve the weld, too.
If I understand the location correctly, that is right about where my bed's front crossmember was banging down on the frame, due to general rot and disrepair. It doesn't take too much of that to weaken the frame.
If the crack is ground out and welded with a full-penetration weld, by a qualified welder, I would resist adding plates. It just makes the frame stiff in that location (only), creating an opportunity for stress to attack the frame at the ends of the plate. It may be desirable to stress relieve the weld, too.
If I understand the location correctly, that is right about where my bed's front crossmember was banging down on the frame, due to general rot and disrepair. It doesn't take too much of that to weaken the frame.
Senior User
Joined: Oct 2005
Posts: 201
Likes: 3
From: Churchville, VA
While I can't comment on the cracks, I did have a frame that was bent. It had a zig-zag under the passenger side cab mount. Body shop straightened it with no troubles. As far as squareness, it seems that back then it wasn't such a big issue, since the frames were built with some flex in them. After my frame was straightened, it was within 1/4" of square measuring diagonally over 48". When I installed the MII frontend, I got it to 1/16". Good enough for me.
If you already have done some prep on one of the frames, I would stick with it and fix the problems. They sound minor to me. My $.02
If you already have done some prep on one of the frames, I would stick with it and fix the problems. They sound minor to me. My $.02
Roast em' if you got 'em
Joined: Mar 2005
Posts: 22,013
Likes: 9,954
From: Rio Rancho, NM
Lets see if I understand this right, frame cracks in the upper flange at the front 2 bed mounting locations directly behind the cab.....yup, got 'em (or had them)
My frame was repaired (and I use the term very loosley here) and I still had cracking across the top flange. I ground things down nice and purty, beveled the edges of the cracks as best I could, welded them up, ground them down smooth, and redrilled the bed mounting holes.
Another common place for cracks is the front crossmember at the 2 front clip/radiator support mount bolt holes. I repaired those also but for those I welded washers to the backside as well. Not sure if it will help, but at the time it seemed like a good idea.
If you have to weld a plate across the frame web, etc, (it would be better if you didn't have to) then fishmouth >_< the edges of the plate. This will help reduce the localized stress points that the plate will cause.
Good luck
Bobby
My frame was repaired (and I use the term very loosley here) and I still had cracking across the top flange. I ground things down nice and purty, beveled the edges of the cracks as best I could, welded them up, ground them down smooth, and redrilled the bed mounting holes.
Another common place for cracks is the front crossmember at the 2 front clip/radiator support mount bolt holes. I repaired those also but for those I welded washers to the backside as well. Not sure if it will help, but at the time it seemed like a good idea.
If you have to weld a plate across the frame web, etc, (it would be better if you didn't have to) then fishmouth >_< the edges of the plate. This will help reduce the localized stress points that the plate will cause.
Good luck
Bobby
Fleet Mechanic
Joined: Mar 2005
Posts: 1,511
Likes: 1
From: peyton, colorado
I had the same crack, just on the pass side. Seems like it's a common flaw. I just ground the crack out and welded. I'll be boxing that area after the drive is sorted so I'm sure it'll be strong enough.
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